[From the U.S. Government Printing Office, www.gpo.gov]







                              S141 OF C-0
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                                                NOAA Technical Memorandum NMFS- AFSC-27
                                            J
                             SPqrE S'Of
                                            Status of Living
                                 Marine Resources off
                                                Alaska, 1993





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        1994















                                               NOAA Technical ME!morandum NMFS





                        The National Marine Fisheries Service's Alaska Fisheries Science Center
                        uses the NOAA Technical Memorandum series to issue informal scientific
                        and technical publications when complete formal review and editorial
                        processing are not appropriate or feasible. Documents within this series
                        reflect sound professional work and ma@ be referenced in the formal
                        scientific and technical literature.


                        The NMFS-AFSC Technical Memorandim series of the Alaska Fisheries
                        Science Center continues the NMFS-F/NWC series established in 1970 by
                        the Northwest Fisheries Center. The now NMFS-NWFSC series will be used
                        by the Northwest Fisheries Science Center.



                        This document should be cited as follows:


                                Low, Loh-Lee. (coordinator) 19,33. Status of living marine resources
                                off Alaska, 1993. U.S. Dep. Corimer., NOAA Tech. Memo. NMFS-
                                AFSC-27, 110 p.

                        Reference in this document to trade names does not imply endorsement by
                        the National Marine Fisheries Service, IqOAA.

















                        This document Is available to the public through:

                        National Technical Information Service
                        U.S. Department of Commerce
                        5285 Port Royal Road
                        Springfield, VA 22161










                                    NOAATechnical Memorandum NMFS-AFSC-27



                         ENT Orr



                                  Status of Living Marine
                                Resources off Alaska, 1993







                                       Alaska Fisheries Science Center
                                   7600 Sand Point Way N.E., BIN C-1 5700
                                           Seattle, WA 98115-0070




















                                      U.S. DEPARTMENT OF COMMERCE
                                            Ronald H. Brown, Secretary
                                  National Oceanicand Atmospheric Administration
                                  D. James Baker, Under Secretary and Administrator
                                         National Marine Fisheries Service
                                Rolland A. Schmitten, Assistant Adminstratorfor Fisheries

         C"
                                                 January 1994
                             LIBRARY
                           NOAA/cCEH
                        1990 HOBSON AVE.
                       'HAS. SC 29408-2623






                                                CONTRIBUTORS

                    This report was written primarily by scientists at the Alaska Fisheries Science Center, National Marine
                   Fisheries Service, with some contributions from the Alaska Department of Fish and Game and the Interna-
                   tional Pacific Halibut Commission. The following personnel were the major contributors:

                   Technical Editors: Loh-Lee Low, James C. Olsen, and Howard W. Braham.

                   Section Contributors:
                    Groundfish Resources Section: Vidar G. Wespestad, Grant G. Thompson, Anne B. Hollowed,
                       Looh-Lee Low, Sandra A. Lowe, Thomas K. Wilderbuer, Terrance M. Sample, Gary E. Walters,
                       Daniel 11 Ito, James N. Ianelli, Harold H. Zenger, Jr., Eric S. Brown, Jeff-fey T. Fujioka,
                       David M. Clausen, Jonathan Heifetz, Victoria M. O'Connell, and Patrick J. Sullivan.
                    Pelagic Resources Section: Vidar G. Wespestad.
                    Shellfish Resources Section: Jerry E. Reeves.
                    Salmon Resources Section: James C. Olsen.
                    Marine Mammal Section: Howard W. Braham.


                   Photograph Selections: Julie A. Pearce.
                   Graphics: Loh-Lee Low.
                   Copyediting: Gary J Duker, James K. Lee, and Susan Calderon.
                   Publication: James K. Lee and Gary J Duker.
                   Coordinator Loh-Lee Low.






                                                                         CONTENTS

                         Overview                                                          IA)h-Lee Low  ................................................................ I
                         Bering Sea/Aleutian islands Groundfish Resources
                                      1.  Walleye, Pollock                                 Mdar G. Vkspestad   ........................................................ I I
                                      2.  Pacific Cod                                      Grant G. Thompson    ........................................................ 14
                                      3.  Yellowfin Sole                                   Thomas K Wilderbiter   .................................................... 17
                                      4.  Greenland Turbot                                 Thomas K. Wilderbuer and Terrance X Sample      ..................... 20
                                      5.  Arrowtooth Flounder                              Terrance M. Sample and Thomas K Wilderbuer      ..................... 22
                                      6.  Rock Sole                                        Thomas; K. Wilderbuer and Gary F. Walters   .......................... 24
                                      7.  Other Flatfish                                   Gary K Walters and Thomas K Wilderbuer      .......................... 26
                                      8.  Pacific Ocean Perch                              Daniel H. Ito and James N. lanetli  ...................................... 29
                                      9.  Other Rockfish                                   Daniel H. Ito  ................................................................ 32
                                    10.   Atka Mackerel                                    Sandra A. Lowe   ............................................................ 34
                                    11.   Squid and Other Species                          Loh-Lee Low    .............................................................. 37
                         Gulf of Alaska Groundfish Resources
                                    12.   Walleye Pollock                                  Anne B. Hollowed   ......................................................... 39
                                    13.   Pacific Cod                                      Harold H. 7enger, Jr . ...................................................... 42
                                    14.   Flatfish                                         Thomas K. Wildertnier and Eric S. Brown  .............................. 44
                                    15.   Sablefish                                        Sandra A. Lowe and Jeffrey T Fujioka   ................................. 46
                                    16.   Slope Rockfish                                   David NL Clausen and Jonathan Heifetz   ............................... 49
                                    17.   Pelagic Shelf Rockfish                           David K Clausen and Jonathan Heifetz    ................................ 52
                                    18.   Demersal Shelf Rockfish                          Victoria X O'Connell and Jeffrey T. Fujioka  ......................... 54
                                    19.   Thomyheads                                       Loh-Lee Low   ............................................................... 56
                                    20.   Pacific Halibut                                  Patrick J. Sullivan  .......................................................... 58
                         Pelagic Resources
                                    21. Pacific Herring                                    Vidar G. Wespestad  ........................................................ 61
                         Shellfish Resources                                               Jerry E. Reeves  .............................................................. 65
                                    22. King Crabs                              .............................................................................................. 66
                                    23. Tanner and Snow Crabs                   .............................................................................................. 71
                                    24. Shrimp and Sea Snails                   .............................................................................................. 74
                         Pacific Salmon Resources                                          James C. 01scm  ............................................................. 77
                                    25. Chum Salmon                             .....................................................................................  ......... 79
                                    26. Pink Salmon                             .............................................................................................. 81
                                    27. Sockeye Salmon                          .............................................................................................. 83
                                    28. Coho Salmon                             .............................................................................................. 85
                                    29. Chinook Salmon                          .............................................................................................. 87
                         Marine Mammals                                                    Howard W. Braham     ....................................................... 91
                                    30.   Bowhead Whale                         .............................................................................................. 93
                                    31.   Gray Whale                            .............................................................................................. 95
                                    32.   Humpback Whale                        .............................................................................................. 97
                                    33.   Killer Whale                          .............................................................................................. 99
                                    34.   Beluga Whale                          .............................................................................................. 100
                                    35.   Dall's Porpoise                       .............................................................................................. 101
                                    36.   Harbor Porpoise                       .............................................................................................. 102
                                    37.   Northern Sea Lion                     .............................................................................................. 103
                                    38.   Northern Fur Seal                     .............................................................................................. 105
                                    39.   Harbor Seal                           .............................................................................................. 107
                                    40.   Spotted Seal                          .............................................................................................. 109



                                                                                            V






                                                                                                          OVERVIEW

                                                                                                                        By Loh-Lee Low


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                     Status of Stocks                                              Gulf of Alaska, pelagic resources, shellfish, salmon,
                                                                                   and marine mammals. There are other resources of
                     off the Coast of Alaska                                       commercial and recreational importance that are not
                                                                                   included in this report; these are mostly inshore
                                                                                   marine resources under the jurisdiction of the State
                        This report provides a species-by-species descriP-         of Alaska.
                     tion of the status of living marine resources off
                     Alaska as assessed for 1993. The descriptions are             Alaska FisherlesSclence Center
                     for resources that are primarily under the research
                     and management jurisdiction of the National Marine                The Alaska Fisheries Science Center (AFSC) is
                     Fisheries Service (NMFS), National Oceanic and                responsible for research on living marine resources
                     Atmospheric Administration, U.S. Department of                in Federal waters off Alaska and parts of the West
                     Commerce. The report was prepared by scientists               Coast of the United States. This region includes the
                     from the NMFS' Alaska Fisheries Science Center,               northeast Pacific Ocean and the eastern Bering Sea,
                     the Alaska of Fish and Game (ADF&G) and the                   which support some of the most important commer-
                     International Pacific Halibut Commission (lPHC).              cial fisheries in the world for Pacific salmon, walleye
                     It is one of a series of regional reports on the status       pollock, Pacific cod, sablefish, flounders, rockfishes,
                     of living marine resources throughout the United              and crabs. The region also supports popular sport
                     States.                                                       fisheries for Pacific salmon, halibut, and steelhead
                        The resources are grouped under six major                  trout and is home to an array of marine mammal
                     headings: groundfish resources of the Bering Sea/             species.
                     Aleutian Islands region, groundfish resources of the


                     Overview














                    65N  140'      150'      160'     170'E      180'     170'W    160'       150'     140'     130'      120'      110' 65'N
                                                                                 
                                               U.S.S.R.
                                                                                           ALASKA

                    60'                               
                                                                                                                                         60'
                                                                     
                                                             
                                                                                  Bering
                                                                                 Sea

                                                                                                                     
                                                                             
                                                                                                                        
                    50'                                       
                                                                                                                                          50'




                                                                                                                     Pacific
                                                 P   A    C     I   F     I      C      0    C    E    A    N        Coast
                    40'                                                                                                                   40'
                                                                                                                                U.S.A.




                    30'
                                                                                                                                                30'


                                                                                   
                                                                                      

                    20o                                                                                                                         20'                        
                                                                                                                          
                         140'      150'      160'       170'E      180'    170' W    160'       150'     140'      130      120'      110'

                    The range of distrubution of  marine resources native to Alaska


                      The mission of the AFSC is to conduct research             fisheries from the early 1950s until the enactment of
                    programs to generate the best scientific data for            the Magnuson Fishery Conservation and Manage-
                    better understanding the region's resources and the          ment Act (MFCMA) in 1977. The implementation
                    environmental quality essential for their existence.         of the MFCMA led to an extremely successful
                    The Center provides scientific data and technical            development of the domestic groundfish industry off
                    advice to its constituents for better utilization and        Alaska. Under the MFCMA, joint ventures with
                    management of these living marine resources. The             foreign countries were first formed to involve
                    Center's primary constituents are the Pacific and            domestic fishermen in the fisheries. Within a short
                    North Pacific Fishery Management Councils, NMFS              3-5 years, most of these joint ventures became
                    headquarters and regional offices, State and Federal         purely domestic operations. Thus a thriving domes-
                    agencies, international fisheries commissions, the           tic groundfish industry was born.
                    fishing and fish processing industry, and the general           Under the MFCMA, the groundfish resources
                    public.                                                      became subject to management by the North Pacific
                                                                                 Fishery Management Council (NPFMC) under two
                    Groundfish Resources                                         fishery management plans (FMPs): one for the
                                                                                 Bering Sea/Aleutian Islands region and the other for
                      The productive waters off the coast of Alaska              the Gulf of Alaska.
                    support some of the world's largest populations of              The long-term potential yield (LTPY) for all
                    groundfish. Large-scale commercial fisheries for             groundfish resources off Alaska (Bering Sea/
                    groundfish were developed and dominated by foreign           Aleutian Islands region plus the Gulf of Alaska)


                    2                                                                                                      Overview
 










                                                       Fisheries Resources off Alaska




                      Species                                   Recent Average Current                            Long-term
                      Group                                     Yield (t)                  Potential              Potential
                                                                (1990-92)                  Yield (t)              Yield (t)

                      -----------------------------------------------------------------
                      Groundfish (BSAI)                         1,664,710                  2,422,495              2,909,500
                      Groundfish (GOA)                          222,760                    734,550                451,070
                      Pacific Halibut (U.S.)                    31,000                     29,000                 30,000
                      Pacific Herring                           45,860                     45,100                 Unknown
                      Shellfish                                 125,220                    125,220                95,370
                      Salmon                                    320,500                    282,200                282,200

                      Total                                     2,410,050                  3,638,565              3,813,240




                    totals more than 3.39 million metric tons (t). The          and Pacific cod. The abundances of flatfishes; and
                    current potential yield (CPY) of 3.19 million t is          Pacific cod are high. Pollock and sablefish abun-
                    close to LTPY, reflecting excellent condition of the        dances are at average levels. The abundances of all
                    stocks. For the Bering Sea/Aleutian Islands region,         rockfishes are generally low. The LT?Y for Gulf of
                    the average groundfish catch in recent years (1990-         Alaska groundfish is 451,000 L The CPY is
                    92) was about 1.66 million t; the 1992 catch of             735,000 t, well above LTPY because flatfishes are
                    1.76 million t had an ex-vessel value above                 particularly abundant. The RAY was 222,700 t,
                    $522 million. For the Gulf of Alaska the average            indicating that the Gulf of Alaska groundfish
                    1990-92 catch was 222,800 t; the 1992 catch of              resources are still substantially underutilized.
                    213,000 t had an ex-vessel value of $133 million.              In addition to the general groundfish complexes,
                       For the Bering Sea/Aleutian Islands region, the          Pacific halibut is a groundfish species that has
                    major species groups harvested are walleye pollock          supported an important traditional fishery for the
                    (77%), Pacific cod (10%). flatfishes (9%), Atka             United States and Canada. The resource is fully
                    mackerel (1.8%), rockfishes (0.9%), and sablefish           utilized and managed by IPHC. The LTPY for the
                    (0.2%). Except for Greenland turbot, all the                entire Pacific halibut resource totals 30,000 to
                    groundfish species are high in abundance and in             36,000 t; the portion in U.S. waters is about 30,000
                    excellent condition. The LTPY or maximum                    L The CPY in U.S. waters is 29,000 t, reflecting the
                    sustainable yield (MSY) for the complex is about            generally good condition of the resource. Recent
                    2.91 million L The CPY of 2.42 million t is 17%             average catches (1990-92) were 31,000 t in U.S.
                    below LTPY, which mostly reflects lower abundance           waters and, including Canada, were 35,700 L
                    of walleye pollock in recent years.
                       The major species groups harvested in the Gulf of        Pelagic Resources
                    Alasks, are walleye pollock (37%), Pacific cod
                    (34%), sablefish (10%), flatfishes (9%), and slope             In the Gulf of Alaska, major concentrations of
                    rockfish (8%). Overall abundance of groundfish in           Pacific herring occur in Southeast Alaska, Prince
                    the Gulf of Alaska has been relatively stable. The          William Sound, and Kodiak Island-Cook Inlet. In
                    most abundant species in the Gulf are flatfishes,           the Bering Sea, they occur in Northern Bristol Bay
                    particularly arrowtooth flounder, followed by pollock       and Norton Sound. In the Chukchi Sea and Arctic


                    Overview                                                                                                         3










                                     Bering Sea-Aleutian Islands Groundfish Resources


                        Species                     Recent Average    Current      Long-term     Status of
                                                    Yield (t)         Potential    Potential     Utilization
                                                    (1990-92)         Yield (t)     Yield (t)
                        ------------------------------------------------------------------------------
                        Pollock                     1,281,000         1,398,700    1,944,600     Full
                        Pacific cod                 170,300           164,500      143,000       Full
                        Yellowfin sole              90,400            238,000      220,000       Full
                        Greenland turbot            5,800             7,000        27,100        Full
                        Arrowtooth flounder         5,600             72,000       59,000        Under
                        Rock sole                   29,900            185,000      160,200       Under
                        Other flatfish              12,100            191,000      148,500       Under
                        Sablefish                   3,270             4,100        10,900        Full
                        Pacific ocean perch         14,500            17,170       14,900        Full
                        Other rockfish              930               1,325        1,300         Full
                        Atka mackerel               30,260            117,100      117,100       Full
                        All Others                  20,650            26,600       62,900        Under


                        TOTAL                       1,664,710         2,422,495    2,909,500




                                                 Gulf of Alaska Groundfish Resources


                        Species                     Recent Average    Current      Long-term     Status of
                                                    Yield (t)         Potential Potential        Utilization
                                                    (1990-92)         Yield (t)    Yield (t)
                        ------------------------------------------------------------------------------
                        Pollock                     81,400            160,000      169,000       Under
                        Pacific cod                 76,680-           56,700       56,700        Full
                        Sablefish                   21,600            20,800       23,500        Full
                        Slope rockfish              17,470            21,580       21,580        Full
                        Flatfish                    21,160            466,750      169,000       Under
                        Thornyhead rockfish         1,500             1,180        3,750         Unknown
                        Pelagic shelf rockfish      2,480             6,740        6,740         Full
                        Demersal shelf rockfish     470               800          800           Full


                        TOTAL                       222,760           734,550      451,070



               Ocean, abundance is low and commercial concentra-         In the Gulf of Alaska, stocks am at moderate to
               tions of Pacific herring have only been located in     high abundance levels and the outlook is for in-
               Kotzebue Sound. The fishery takes place in inshore     creases as a strong 1988 year class recruits to the
               areas.                                                 fisheries. In the Bering Sea, Pacific herring stocks
                  The LT?Y for Pacific herring off Alaska is not      declined through the 1980s as the very strong 1977-
               known because stock abundance is highly variable.      78 year classes which sustained the fisheries aged
               The CPY is about 45,100 L The 1992 total Pacific       and declined in abundance. In 1992, a strong 1988
               herring harvest of 56,400 t (23,850 t in the Gulf of   year class recruited into the fishery and those fish
               Alaska and 32,550 t in the Bering Sea) had an ex-      should further increase abundance of the stocks in
               vessel revenue of $30 million. The majority of the     1993.
               harvest was roe herring and the remainder was food
               and bait herring and roe-on-kelp.


               4                                                                                           Overview











                     Shellfish Resources                                         1992 catch in the Gulf of Alaska was about 900 t'
                                                                                 worth about $680,000. Shrimp catches used to be
                        T'he king and Tanner crab fisheries we currently         fairly large in the Bering Sea in the early 1960s
                     the most important shellfish fisheries off Alaska           (32,000 t in 1963). The fishery ceased operation in
                     71iree species of king crab (red, blue, brown or            1973 after the resource was depleted by foreign
                     golden) and two species of Tanner crab                      fisheries.
                     (Chionoecetes bairdi and C. opilio) are harvested              The sea mail stocks are located primarily in the
                     commercially. Historically, red king crab has               eastern Bering Sea shelf. Ile stock is underutilized
                     predominated in king crab landings. In recent years,        because the fishery for sea mails is undeveloped.
                     blue and brown king crab have become relatively             The status of the snail stocks is not clear, although
                     more importanL                                              resources are known to be generally abundanL
                        During the developmental phase of the Tanner                Besides the major shellfish resources summarized
                     crab fishery, C. bairdi dominate the landings. In           above, fishermen also harvest the following shellfish
                     more recent years, there has been a shift in species        resources mostly within State waters: Dungeness
                     composition; the C. opilio catch is currently 10-           crab, Korean horse hair crab, sea cucumber, sea
                     times the C. bairdi catch.                                  urchin, scallop, abalone, geoduck, and octopus. The
                        The annual ex-vessel value of Alaskan king and           combined value of these catches in 1992 (4,W t)
                     Tanner crab fisheries averaged $195 million during          was $13 million.
                     the 1978-90 period. The 1992 value was
                     $287 million; 25% ($70 million) was attributable to         Salmon Resources
                     king crab and the rest to Tanner crab. The Bering
                     Sea crab stocks are jointly managed by the State of            There are five species of Pacific salmon: chum,
                     A]-q.qk-q and the Federal government under an FM[P          pink, sockeye, coho, and chinook salmon. Pacific
                     of the NPFMC. Gulf of Alaska crab and shrimp                salmon are anadromous; they spawn in fresh water,
                     resources are managed by the State of Alaska                migrate and rear in the open ocean, and return to
                        The U.S. fishery for shrimp in Alaskan waters is         their home stream or lake to repeat the life cycle.
                     currently at a low level. The western Gulf of Al-asksk         The Pacific salmon fishery in Alaska contributes
                     has been the main area of operation. From the               significantly to the food supply and economy of the
                     1960s, catches rose steadily to about 58,000 t in           Nation and ranks as the largest non-government
                     1976, and declined precipitously after that time.           employer in Alaska with sales exceeding those of
                     During the 1960-90 period, the ex-vessel value of           tourism, mining, or forest products. The fishery
                     western Alaska shrimp fisheries averaged $4 million         provides adundant recreational opportunities and is
                     annually, with a peak value of $14 million in 1977.         an integral part of Alaska native culture and heri-
                     Since 1988, shrimp catches have been minor. The             tage. Recent catches (1990-92) exceed 155 million


                                                             Pacific Herring Resource


                         Species                        Recent Average Current                 Long-term              Status of
                                                        Yield (t)              Potential       Potential              Utilization
                                                        (1990-92)              Yield W         Yield (t)

                         ------------------------ ---------------------------------------------------
                         Bering Sea-Aleutians 23,230                           28,200          Unknown                Full
                         Gulf of Alaska                 22,630                 16,900          Unknown                Full


                         Total                          45,860                 45,100          Unknown                Full






                     Overview                                                                                                           5













                                                       Pacific Halibut Resource


                       Species                     Recent Average    Current        Long-term       Status of
                                                   Yield (t)         Potential      Potential       Utilization
                                                   (1990-92)         Yield (t)      Yield (t)
                       ---------------------------------------------------------------------------------
                       Bering Sea-Aleutians        3,600             2,800          ---             Full
                       Gulf of Alaska              27,200            25,900         ---             Full
                       Pacific Coast               200               300            ---             Full
                       Off Canada                  4,700             4,500                          Full


                       Total                       35,700            33,500-        30,000-36,000   Full
                       U.S. Total                  31,000            29,000



                         Higher by 16,000 t if     sports catch, bycatch, and waste are included.

                                                     Alaska Shellfish Resources



                       Species                     Recent Average    Current        Long-term       Status of
                                                   Yield (t)         Potential      Potential       Utilization
                                                   (1989-91)         Yield (t)      Yield (t)
                       -----------------------------------      ---------------------------------------------


                       King crabs                  12,710            12,710         27,070          Full
                       Tanner crabs                112,510           112,510        40,900          Full
                       Shrimp                      0                 300            22,600          Full
                       Sea snails                  0                 1,800          4,800           Under


                       Total                       125,220           125,220        95,370



                                                     Alaska Salmon Resources


                                                                     Curient
                       Species                     Recent Average    Potential      Long-term       Status of
                                                   Yield (t)         Yield (t)      Potential       Utilization
                                                   (1990-92)         (1980-92)      Yield (t)
                       ---------------------------------------------------------------------------------
                       Pink                        127,300           113,200        113,200         Full
                       Sockeye                     138,900           109,000        109,000         Full
                       Chum                        31,700            38,200         38,200          Full
                       Coho                        17,800            16,100         16,100          Full
                       Chinook                     4,800             5,700          5,700           Full


                       Total                       320,500           282,200        282,200         Full




               fish or 320,500 L Ex-vessel value of the 1992 catch    complex niixture of domestic and international
               was about $575 million.                                bodies, treaties, regulations and agreements. The
                  Management of Pacific salmon in Alaska's vast       State of Alaska has prime responsibility for manag-
               marine area with a coastline of nearly 34,000 miles    ing the Pacific salmon resource, where most of the
               is accomplished by Federal and State agencies in a     fishery takes place inshore. Management in the U.S.

               6                                                                                           Overview











                   Exclusive Economic Zone (EEZ) is the
                   responsibility of NMFS and the               Status of Resident and Selected Species
                   NPIFMC.                                             of Marine Mammals off Alaska'
                      Recreational fishing is permitted in
                   all regions of the EEZ off Alaska under
                   ADF&G regulations. The recreational       Species                                       Trends
                   catch in the EEZ is probably less than                             Abundance            (% Change)
                   several hundred salmon with most          -----------------------------------------------------
                   taken in the charter boat fishery. The    Bowhead whale            7,500                +3.1/yr
                                                                                                           (1978-88)
                   statewide sport catch within State
                   waters in 1990 was about 909,000 fish.    Gray whale               20,869               +3.3%/yr
                      The five species of Pacific salmon                              (19,737-22,489)      (1968-88)
                   are fully utilized. The stocks have       Humpback whales          >2,000               Unknown
                   generally rebuilt to or are beyond
                   previous high levels. On a regional       Killer whale             >300                 Unknown
                   basis, some stocks may be overutilized    Beluga                   15,800-18,450        Unknown
                   because of mixed stocks in the catch.

                                                             Dall's porpoise          300,000-600,000      Unknown
                   Marine Mammal Resources
                                                             Harbor porpoise          Unknown              Unknown

                      Forty-two species of marine            Northern sea lion        >34,844              -70%
                   mammals in U.S. waters of the North
                   Pacific Ocean are under the jurisdic-     Northern fur seal        982,000              -50%
                   tion of the U.S. Department of Com-                                                     (1975-90)
                   merce. These include 31 species of        Harbor seal              Uncertain            -60%
                   whales, dolphins and porpoises, and                                (<1001000)           (1976-92)
                   11 species of seals and sea lions. Six    Spotted2 seal            Unknown              Unknown
                   species are found only in Alaska.
                      Fourteen of the most commonly
                   observed species of marine mammals
                   are normally found close to shore. The      Bowbead, gray, and humpback whale estimates
                                                               are for the entire eastern North Pacific
                   other species usually remain in             Ocean; all others are for Alaska.
                   offshore waters, on remote islands, or    2 Other ice-associated seals are the bearded,
                   am rare in number and seldom seen.          ribbon, and ringed seals.
                   Most marine mammals make long-
                   distance migrations or move thousands of miles        under the Marine Mammal Protection Act (MI@IPA)
                   within smaller areas of the ocean between seasons of  of 1972 and the Endangered Species Act (ESA) of
                   the year. These movements occur when marine           1973.
                   mammals, especially whales and dolphins, travel
                   Erom one feeding ground to another or spend the
                   breeding season in lower latitudes and the major
                   feeding and calf-rearing seasons in higher latitudes.
                      There are several populations of marine mam-
                   mals that only spend a portion of the year in Alaska,
                   such as humpback whales and northern fur seals,
                   whereas others are found year-round inAlaska, such
                   as the bowhead whale. These zoogeographic
                   differences have lead to unique life history strategies
                   and result in the need to manage accordingly.
                   Management of marine mammals is carried out

                   Overview                                                                                              7






















                                                                                                                        Z

















                    2%






                                           -WK


                                                                                                                 _L_   Al

                                                                                                                   Photo: 1PHC

                 Glossary of Common
                 Abbreviations and Terms

                 MFCMA         Magnuson Fishery Conservation and            ABC     Acceptable biological catch. A catch
                               Management Act of 1976.                      level that can be justified on biological and ecologi-
                 ESA           Endangered Species ACL                       cal grounds without reference to social or economic
                 MMPA          Marine Mammal Protection ACL                 factors. Scientists use various mathematical meth-
                 NMF'S         National Marine Fisheries Service.           ods to estimate ABC, depending on the stock type
                 NOAA          National Oceanic and Atmospheric             and available data. Similar to current potential yield
                               Administration.                              (CPY).
                 AFSC          Alaska Fisheries Science Center
                 NWFC          Northwest Fisheries Science Center           LTPY -- Long-term potential yield: The maxi-
                 SWFC          Southwest Fisheries Science Center           mum long-term average yield (catch) from the
                 ADFG          Alaska Department of Fish and Game           resource. It is similar to maximum sustainable yield
                 NPFMC         North Pacific Fishery Management             (MSY).
                               Council
                 PFMC          Pacific Fishery Management Council           CPY -- Current potential yield: The current catch
                 INPFC         International North Pacific Fisheries        that may be obtained from the resource. It is similar
                               commission.                                  to acceptable biological catch (ABC) which mea-
                 CalCOF1       California Cooperative Oceanic               sures the biological production potential of the stock.
                               Fisheries Investigations.
                 IEPHC         International Pacific Halibut                RAY -- Recent average yield: This is current
                               Commission                                   average catch, denoted usually by a specific time
                   CO.'
































                                                                            period.

                 8                                                                                                  Overview










                        TAC -- Total allowable catch: Total allowable                  F0.1    is a point at which the increase in yield for
                        catch is the total regulated catch from a stock in a           increased effort is 10% of what it was when fishing
                        given time period, usually a year.                             mortality was very low.

                        Mortality rates: The rate at which fish die from               F,,,, is the fishing mortality rate that reduces
                        natural causes or through fishing. Mortality rates             spawning biomass per recruit ratio to 35% of the
                        can be described in several ways. The easiest--total           unfished level. This rate has often been adopted by
                        annual mortality rate--defines the fraction of the fish        the PFMC and NPFMC as the fishing rate to
                        within a group that die during the year. These rates           calculate ABC. The F3,,, has often been adopted as
                        are difficult to use mathematically when describing            the F...... rate.
                        the relative contribution of different types of natural
                        or fishing mortality to the total mortality of fish            CPUE - Catch per unit effort: This is an index of
                        during a year. Thus, instantaneous mortality is used.          stock abundance.
                        Instantaneous mortality rate: An instantaneous                 Recruitment: The amount of fish, in numbers or
                        mortality rate is the fraction of the population of fish       weight, that reach a certain size or age in a specific
                        that dies in a very short (instantaneous) period of            year. For example, all fish reaching their second
                        time. There is a relatively simple mathematical                year would be age-2 recruits. This is often used to
                        conversion between instantaneous rates and annual              describe the strength of a year class.
                        rates. For example, the total instantaneous mortality
                        rate, often denoted by Z, is equivalent to the annual          Year class (or cohort): Fish of the same stock born
                        rate A, according to the formula: A = 1 - e-z .                in the same year. Occasionally a stock produces a
                                                                                       very small or very large year class and tins group of
                         M -- Natural mortality is the mortality due to                fish is followed closely by assessment scientists since
                        natural causes.                                                it can be pivotal in determining the stock abundance
                         F -- Fishing mortality is the mortality due to                in successive years.
                        fishing.
                         Z -- Total mortality rate is the combined effect of           Population: An interbreeding group of living marine
                        all sources of mortality acting on a fish population.          organisms, such as a species in a geographic area.
                        Thus Z = M + F.
                                                                                       Stock: A portion of the population that is reason-
                        Reference fishing mortality rates: There are                   ably well mixed and is geographically distinct in
                        specific rates of F that measure how close a stock is          terms of fishery and management.
                        to full exploitation. They are defined in terms of an
                        increase in yield from a year class over its lifespan as
                        fishing mortality increases. When no fish are taken,
                        there is no yield from the year class. As fishing
                        increases, the yield increases, but at a decreasing
                        rate.


                         F.      is the point at which the increased yield for
                        additional effort is zero; that is, additional fishing
                        mortality will not increase yield, but in fact, may
                        decrease it as fish are caught before they are fully
                        grown.

                         F..,    is the rate of fishing mortality when
                        maximum sustainable yield for the stock is achieved.



                        Overview                                                                                                              9





                                                                      1, WALLEYE POLLOCK

                                                                                                               By Vidar G. Wespestad




                                                                           F
                                                                                  7
                                                                                                                40

























                                                      _oc








                                                                                                                             Photo: AFSC
                          The walleye pollock (Theragra chalcogramma)              Islands region.
                       is the most abundant groundfish species in the                 Bering Sea pollock recruit to the fishery at age 3-
                       eastern Bering Sea/Aleutian islands region, compris-        4 years, which corresponds to their age of maturity,
                       ing well over 50% of the total groundfish catch.            at an average size of 35-40 cm and 0.25-0.40 kg.
                       Total ex-vessel value of the 1.2 million t catch in         The rate of natural mortality of exploited pollock is
                       1991 was $232 million. Walleye pollock is a                 0.3 and they survive in significant numbers to age 9.
                       semidernersal species that is primarily pelagic             Strong year classes persist to about age 16-18 years
                       during the first few years of life and then becomes         in the commercial catch. The maximum observed
                       increasingly demersal in behavior as it ages.               age for pollock is 31 years. Maximum length is
                          The species is found in greatest abundance along         91 cm and maximum weight is 5 kg.
                       the outer continental shelf and slope between the 100          From 1954 to 1963, pollock were harvested at
                       and 500 m depth contours. Pollock migrate from              low levels in the eastern Bering Sea. Directed
                       deep to shallow water in summer and return to deep          fisheries began in 1964. Catches increased rapidly
                       water in autumn. They are both bottom and pelagic           during the late 1960s and reached a peak of
                       feeders and consume plankton, krill, and fish. The          1.9 million t in 1972. Since 1977, catch quotas have
                       walleye pollock is highly cannibalistic, with its           ranged from 950,000 to 1.3 million t. Catches in the
                       young a major component of its diet. They also              Aleutian Islands region have always been less than
                       occur pelagically in deep waters of the Aleutian            those in the eastern Bering Sea. Catches in this area
                       Basin. Stock structure of pollock has not been well         increased from 1980 to 1984 due to increased
                       delineated. For the purpose of management within            foreign effort and have decreased in recent years as
                       the U.S. EEZ, the resource is divided into two major        the foreign fishery was phased out and domestic
                       regions: the eastern Bering Sea and the Aleutian            fisheries began to exploit the resource.


                       Bering Sea/Aleutian Islands Groundfish Resources                                                                   1














                                                          WALLEYE POLLOCK
                                      Eastern Bering Sea, Aleutian Islands and Aleutian Basin
                                                       COMMERCIAL CATCH (1,000 t)



                                                             AlpijtjAn Tq1&Q"                        Al aut i an
                                                                                                        Ragin
                          Year Foreign      JVP     DAP      Foreign JVP DAP           Total
                          ----------------------------------------------------------------------------
                          1977     978       0       0           8     0     0           986                0
                          1978     979       0       0           6     0     0           985                0
                          1979     914       0       0           10    0     0           924                0
                          1980     948      11       0           58    0     0        1,017                 15


                          1981     931      42       0           56    0     0        1,029                 1
                          1982     903      53       0           56    2     0        1,014                 4
                          1983     835     145       1           56    3     0        1,040                 71
                          1984     862     230       6           70    7     4        1,179               181
                          1985     771     370       38          51    7     1        1,238               336


                          1986     337     805       47          15    30    1        1,235             1,061
                          1987        4   1,015     218          0     28    1        1,266             1,325
                          1988        0    739      489          0     41    2        1,271             1,396
                          1989        0    227      952          0     5   11         1,195             1,399
                          1990        0     22   1,180           0     0   79         1,259               917
                          1991        0      0    1,038          0     0   79         1,117               297
                          1992        0      0    1,348          0     0   so         1,398                 3



                          JVP:  Joint Venture  Processing                 DAP: Domestic Annual Processing




                   Two important developments occurred in the            Assessment of eastern Bering Sea pollock utilizes
                Bering Sea pollock fishery in the 1980s. Ile first     mformation from age-structured models, bottom
                was the initiation of high-seas pollock fisheries in   trawl surveys, and hydroacoustic surveys. Bottom
                the central Bering Sea (the "donut hole" area)         trawl surveys have been conducted annually since
                outside of the U.S. and Soviet'FF7- . The second       1977 and hydroacoustic surveys have been repeated
                was the development of a U.S. fishery on spawning      trienally since 1979. Three age-structured popula-
                pollock in the vicinity of Bogoslof Island (Bering     tion dynamics models have been employed to assess
                Sea Area 518). In 1984, the donut hole catch was       pollock: cohort analysis, a catch-at-age model
                only 18 1,000 L The catch grew to a peak of            (CAGEAN), and a stock synthesis model. All three
                1.4 million t in 1989; this exceeded the pollock catch models show the same biomass trend, however, the
                within the U.S. Bering Sea EEZ. The catch fell         cohort model results are reported below to indicate
                rapidly to 917,000 t in 1991 and 297,000 t in 1992.    biomass levels.
                The donut hole fishery ended in 1993 under terms of      The abundance of pollock in the eastern Bering
                a temporary (1993-94) multilateral moratorium. The     Sea has risen from a low of 4.0 million t in the late
                Bogoslof fishery occurs in deep water off the eastern  1970s (induced by large removals in the early to
                Bering Sea shelf. In 1987 the catch was 377,000 L      mid-1970s and by reduced recruitment) to a peak of
                It decreased by 36,100 t in 1989, but increased to     15.8 million t in 1985. Most of the increase during
                264,800 t in 199 1. In 1992, fishing in the Bogoslof   the early 1980s was due to the recruitment of a very
                Island area was prohibited in response to the rapid    strong 1978 year class. The population has since
                decline of Aleutian Basin pollock abundance;           been declining following lower levels of recruitment
                biological information suggests that fisheries in the  in the early 1980s and aging of the 1978 year class.
                Aleutian Basin and the Bogoslof Island area are        A strong 1989 year class began recruiting into the
                harvesting the same group of fish.                     fishery in 1992. This year class is expected to


                12                                       Bering Sea/Aleutian Islands Groundfish Resources














                                                                                        WALLEYE POLLOCK
                                                                             Eastern Bering Sea and Aleutian Islands



                                                                                               V.Aqt-@rn Rpriner _qAa                        Alpiltian Tslands


                             Average catch (1977-92)                                             1.1 million t                                     39,071 t
                             Long-term potential yield (MSY)                                     1.8 million t                                     144,600 t
                             Acceptable biological catch (1993)                                  1.34 million t                                    58,672 t
                             Fishing strategy                                                    F351                                              F35%
                             Age of recruitment                                                  3 years
                             Size at recruitment                                                 35 cm, 251 g
                             Maximum age                                                         31 years
                             Abundance and trend                                                 Moderate-stable                                   Unknown
                             Recreational importance                                             None                                              None
                             Subsistence use                                                     Minor                                             Minor
                             Management                                                          BSAI Groundfish          FMP
                             Assessment Method                                                   Age structured                                    Trawl survey
                             Status of exploitation                                              Fully exploited                                   Fully exploited
                             M                                                                   0.30                                              0.20
                             FwY
                                                                                                 0.38
                             F (35%. 1*931
                                                                                                 0.37                                              0.42




                          contribute significantly to the fishery for the next                         For further information
                          few years and end the declining trend. Trawl
                          surveys also indicate that the 1990 and 1991 year                            Wespestad, V. G., and P. Dawson. 1992. Walleye
                          classes may be above average. If these year classes                          pollock. In Stock assessment and fishery evaluation
                          hold up, then eastern Bering Sea pollock biomass is                          document for groundfish resources in the Bering
                          expected to continue increase through the mid-                               Sea/Aleutian Islands region as pmjected for 1993.
                          1990s. Ile ABC for the eastern Bering Sea stock                              North Pacific Fishery Management Council, P.O.
                          was estimated to be 1.34 million t from a biomass of                         Box 103136, Anchorage, AK 99510.
                          5.9 million t in 1993.
                              Sufficient data are not available to
                          perform an age-structured analysis for                                                    Walleye Pollock
                          the Aleutian Islands stock; thus the                                              Bering Sea/Aleutian Islands
                          biomass is estimated from occassional
                          trawl surveys. The 1993 exploitable                        3.5- Catch @Million t)                                        Biomass (Million t)    21
                          biomass is estimated to be 195,6W t@                                 _4@_ Cohort Biomass
                          with an ABC of 58,700 L                                       3--    =   Bogoslof                                                           --- 18
                              For the Bogoslof Island area,                          2.5- -        Donut Hote                                                           -15
                          occasional hydmcousfic surveys welre                                     Aleutian isianas
                          conducted during February-Mmh to                              2---   1=1 E.Bering Sea
                          estimate the spawning biomass. Ile
                          biomass was estimated to be
                          2.4 million t in 1988, 2.1 million t in
                          1989, 0.6 million t in 199 1, and
                          0.8 million t in 1992. The ABC was                         0.5                                                                                  3
                          estimated to be 169,000 t in 1993.

                                                                                       0                                                                                  0
                                                                                            77 78 79 80 81          82 83    84 85     86 87 88 89 90 91            92
                                                                                                                              Year


                          Bering Sea/Aleutian Islands Groundfish Resources                                                                                                13





                 2. PACIFIC COD

                 By Grant G. Thompson



























                   In North American waters, Pacific cod (Gadus                 Tagging studies have demonstrated significant
                 macrocephalus) are distributed from Santa Monica           migration of Pacific cod between the Bering Sea and
                 Bay, California, through the Gulf of Alaska, Aleu-         the Aleutian Islands region. Therefore, the resource
                 tian Islands, and eastern Bering Sea to Norton             is managed as a single unit under the NPFMC'S
                 Sound. They occur demasally on
                 the continental shelf and upper                                Pacif ic Cod
                 continental slope. They are                                Eastern Bering Sea
                 omnivorous. feeders that attain sizes
                 in excess of 100 cm in length and             Catch (1,000 metric tons)          Biomass (1.000 metric tons) 1400
                 20 kg in weighL Ages up to                20
                 18 years have been observed,                                                  Biomass                    1200
                 although young fish (ages 3 to 8)         150-                                                           1000
                 comprise the bulk of the catch.
                 Spawning occurs between January                                                                          800
                 and April, perhaps peaking in             100-                                                           600
                 Mamh. Pacific cod is harvested                                   Cat
                 using a variety of gear types,                                                                           400
                 including (in order of catch vol-          50 -
                 umes) trawl, longline, and pot gear.                                                                     200
                 Fishing has historically occurred           0                                                            0
                 year-round-                                    77 78 79 80 81 82    83 84 85 86 87    88 89 90 91 92
                                                                                         Year


                 14                                           Bering Sea/Aleutian         Islands Groundfish Resources










                   FMP for groundfish of
                   the Bering Sea and                                      PACIFIC COD
                   Aleutian Islands                          Eastern Bering Sea and Aleutian Islands
                   region. Although
                   foreign and joint       Average catch (1977-92)                           =  115,000 t
                   venture flew were       Long-term potential yield                         =  143,000 t
                   major participants in   Acceptable biological catch (1993)                =  164,500 t
                                           Age/length at recruitment                         =  3 yrs/42 cm
                   the flShUY throughout   Age/length at 50% maturity                        =  5.3 yrs/61 cm
                   most of the 1980s,      Maximum observed age                              =  18 yrs
                   growth in the domes-    Abundance and trend                               =  Average, declining
                   tic fleet has altered   Stock biomass (age 3+, model projection)          =  690,000 t
                                           Harvest strategy                                  =  F33,
                   this picture drarnati-  Importance of recreational fishery                =  Negligible
                   cally. Ile foreign      Management                                        =  BSAI Groundfish FMP
                   fleet has not received  Status of exploitation                            =  Fully exploited
                   an allocadon since      Projected spawning stock per recruit              =  Above maintenance level
                   1987, and the joint     Assessment Method                                 =  Age structured
                   venture fleet has not   Fc., = 0.142    F30% = F@rf,"Im = 0.139    F...   0.427    F30% = 0.121
                   received an anoCafion                  0.11      F1112 0.148      M = 0.29
                   since IM. Pacific
                   cod catches have
                   increased substantially from the average level of      exceptionally strong year class spawned in 1977.
                   41,000 t observed from 1977 to 1979. Total landings    Good (though not exceptional) year classes were
                   peaked in 1988 when 198,000 t were taken in the        spawned in 1978 and 1982, helping to sustain a high
                   eastern Bering Sea and Aleutian Islands region.        biomass level. Throughout the 1980s, trawl survey
                   Total landings in 1991 were the second highest on      estimates of biomass for the eastern Bering Sea
                   record, with 176,000 t reported for the two areas.     portion of the stock exceeded 900,000 L, peaking in
                   Without exception, the vast majority of the com-       1987 at 1,142,000 L Model estimates of biomass for
                   bined-area catches are taken in the eastern Bering     this area and period show a similar abundance trend.
                   Sea.                                                   However, back-to-back poor year classes from 1986
                      Currently, the stock is declining following a       and 1987 have led to a pronounced decline from the
                   period of high abundance that was fueled by an         high biomass levels observed during most of the



                                                                    PACIFIC COD
                                                   Eastern Bering Sea and Aleutian Islands
                                                        . COMMERCIAL CATCH (1,000 t)



                                                1983    1984    1985  1986   1987   1988    1989   1990    1991  1992


                         -----------------------------------------------------------------------------------
                         Eastern Bering Sea
                          Foreign               39      57      56    40     54     0       0      0       0     0
                          Joint Venture         10      24      36    58     47     107     44     8       0     0
                          Domestic              34      29      41    33     42     86      120    155     167   126
                          Subtotal              83      ill     133   131    143    193     165    163     167   126


                         Aleutian Islands
                          Foreign               2       1       1     0      0      0       0      0       0     0
                          Joint Venture         5       6       6     6      10     3       0      0       0     0
                          Domestic              3       14      6     4      3      2       4      8       8     38
                          Subtotal              10      22      13    10     13     5       4      8       8     38


                         Total                  93      133     145   141    157    198     169    171     176   164




                   Bering Sea/Aleutian Islands Groundfish Resources                                                       15









                1980s. The trawl survey biomass estimates for the
                eastern Bering Sea portion of the stock in 1990,
                1991, and 1992 were only 709,000 L, 533,000 t, and
                547,000 t, respectively, with model estimates of
                biomass coming in only slightly higher. Although
                the stock is declining, this is more likely due to
                unusually low recruitment than to excessive fishing.
                The MSY for Pacific cod cannot be accurately
                estimated; however, historical data suggest the LTPY
                to be 143,000.L


                For further information


                Thompson, G. G. 1992. Pacific cod. la Stock
                assessment and fishery evaluation document for
                groundfish resources in the Bering Sea/Aleutian
                Islands region as projected for 1993, p. 2:1-2:37.
                North Pacific Fishery Management Council, P.O.
                Box 103136, Anchorage, AK 99510.

                Thompson, G. G., and R. G. Bakkikin 1990.
                Assessment of the eastern Bering Sea Pacific cod
                stock using a catch-at-age model and trawl survey
                data. Int. North Pac. Fish. Comm. Bull. 50:215-236.




























                16                                        Bering Sea/Aleutian Islands Groundfish Resources





                                                                      3, YELLOWFIN SOLE

                                                                                                  By Thomas K. Wilderbuer







                                                                                       4<7




                                                                                                      r




                                                                                   177

                                                                                                                         -0i




                                                                                                                  Photo: AFSC
                       Yellowfin sole (Pleuronectes asper) inhabits        these nearshore waters and gradually shift to deeper
                    continental shelf waters of the North Pacific Ocean    water and, at lengths of 16 to 20 cm (mainly ages 5-
                    from off British Columbia, Canada, to the Chukchi      8 years), they begin occupying much the same waters
                    Sea. It is the most abundant flatfish                  as the larger fish.
                    in the North Pacific Ocean and by
                    far the most abundant in the eastern                    Yellowf in Sole
                    Bering Sea--the only region in            Eastern     Bering Sea/ Aleutian Islands
                    North America where it forms
                    commercially harvestable concen-       600- Catch (1,000 metric tons)       Biomass (1,000 metric tons)  4000
                    trations.
                       Yellowfin sole is a small flatfish  500-                                          Survey
                    attaining a maximum size of about                                                     Biomass     -3000
                    40 cm and 700 g; it averages about     400-
                    26 cm and 200 g in commercial                           Catch
                    catches. In summer, yellowfin sole     300-                                                       -2000
                    are found from nearshore areas to                                    Biomass
                    depths of about 100 m. In winter,      200-                         SS Mod                         1000
                    concentrations of adults move to       100-
                    depths between 50 and 200 m to
                    avoid ice cover. Spawning occurs          0-                                                      0
                    from June to August in nearshore           54 57 60 63 66 69 72 75 78 81 84 87 90
                    waters. Young juveniles develop in                                  Year

                    Bering Sea/Aleutian Islands Groundfish Resources                                                        17


















                                                                     YELLOWIN SOLE
                                                                     Eastern Bering Sea
                                                                 COMMERCIAL CATCH (1,000 t)



                      Category           1983     1984     1985      1986     1987     1988     1989      1990      1991    1992
                      ----------------------------------------------------------------------------------------
                      Domestic           0        0        0         0        0        9.8      1.7       10.9      84.5    106.0
                      Joint-
                        venture          22.5     32.8     126.4     151.4    179.6    213.3    151.5     69.7      0       0
                      Foreign
                         Japan           64.8     83.9     59.5      49.3     1.1      0        0         0         0       0
                         U.S.S.R.        0        8.0      8.2       0        0        0        0         0         0       0
                         ROK             21.0     34.9     33.0      7.6      0.7      0        0         0         0       0
                         Others          0        0        0         0.2      0        0        0         0         0       0


                      Total              108.4    159.5    227.1     208.6    181.4    223.2    153.2     80.6      84.5    106.0




                      FAstern Bering Sea yellowfin sole are from a                Cohort analysis and stock synthesis modeling
                  single stock. Their distribution extends into the            indicate that stock abundance during the 1980s was
                  Aleutian Islands region but only to a limited extent         as high, if not higher, than abundance during the
                  and in minor abundances.                                     early years of the fishery. Surveys have shown
                      Fisheries for yellowfin sole were initiated by           unreasonable biomass fluctuations in the 1980s
                  Japan in 1954. Japanese and other foreign fisheries          ranging from 1.8 to 3.9 million t. Nevertheless,
                  continued to take yellowfin sole until 1987, after           even the lower estimates demonstrate that the
                  which all of the catch was allocated to U.S. fisheries.      abundance of yellowfin sole remains high. The 1992
                  The species was intensively exploited for fish meal          survey estimate was 2.2 million L Results from
                  during the early years of the fisheries, with catches        stock synthesis indicate that biomass was as high as
                  ranging as high as 553,700 t (in 1961) and averag-           2.8 million t in 1984 and is estimated at 2.6 million t
                  ing 404,000 t in 1959-62. Catches of this magnitude          in 1992.
                  were more than the stock could sustain and subse-
                  quently they caused a sharp decline in abundance.
                  Following a recovery
                  of stock abundance
                  during the 1970s,                                                 YELLONFIN SOLE
                  catches have ranged as                                          Eastern Bering Sea
                  high as 227,100 t (in
                  1985) and averaged            Average catch (1977-92)                             =  131,793 t
                  131,793 t from 1977 to        Long-term potential yield (MSY)                     =  155,000-284,000 t
                                                Exploitable biomass (1993)                          =  2,504,500 t
                  1992. Catches                 Acceptable biological catch (1993)                  =  238,000 t
                  declined to 106,OW t          Fishing strategy                                       F330
                  in 1992 mainly as a           Abundance and trend                                 =  High and declining
                  result of limitations on      Status of exploitation                              =  Under-exploited
                                                Importance of recreational fishery                  =  Nonexistent
                  bycatch of prohibited         Management                                          =  BSAI Groundfish FMP
                  species rather than to a      Age/length    at 50% maturity                       =  Males: 7 years/20.3 cm
                  decline in abundance.                                                                Females: 8 years/23.8 cm
                  Yellowfin sole has            Age/length    at 50% recruitment                    =  Males: 9 years/26.1 cm
                                                                                                       Females: 9 years/27.1 cm
                  been mainly utilized          Maximum age                                         =  30 years
                  for human consump-            Assessment Method                                   =  Age structure model
                  tion since the early
                  1960S.                        M = 0.12      F0.1 = 0.14      FN_ = 0.50      F3.s%=  0.118
                                                F 1977-92        0.061 F-riaim= 0.17


                  18                                             Bering Sea/Aleutian Islands Groundfish Resources









                      I'he primary reason for the recovery of the stock
                   during the 1970s and early 1980s was the recruit-
                   ment of a series of stronger than average year classes
                   spawned in 1968-77. Many of these year classes still
                   support the population and there is good recruitment
                   from some later year classes. particularly 1981,
                   which may be one of the strongest yet observed. and
                   a good 1983 year class. Abundance of eastern
                   Bering Sea yellowfin sole is at a high level and
                   strong incoming year classes should maintain the
                   stock in good condition.


                   For further information


                   T. K. Wilderbuer. 1992. Yellowfin sole. In Stock
                   assessment and fishery evaluation document for
                   groundfish resources in the Bering Sea/Aleutian
                   Islands region as projected for 1993. North Pacific
                   Fisheries N[anagement Council, PO. Box 103136,
                   Anchorage, AK 99510.


























19







                   Bering Sea/Aleutian islands Groundfish Resources                                                          19





                  4. GREENLAND TURBOT
                 By Thomas K. WiWerbuer and Terrance M. Sampk











                                            A-
                                                                                Vd. 2-
                                                                               "N-T

                                                                        C"Mi
                                                                                                   0.











                    Greenland turbot (Reinhardtius hippoglossoides)         between 63,000 and 78,000 t from 1972 to 1976.
                are distributed in the Atlantic and Pacific Oceans.         Catches declined in the late 1970s but were still
                In the North Pacific, they are most abundant in the         relatively high in 1980-83 with annual catches
                eastern Bering Sea and Aleutian
                Islands region. It is a demersal
                flatfish species. Juveniles inhabit                       Greenland Turbot
                the continental shelf waters of the           Eastern Bering Sea/ Aleutian Islands
                eastern Bering Sea until about 4 or
                5 years of age. Older age groups am            Catch (1,000 metric tons)          Biomass (1.000 metric tons)
                found in continental slope waters at       100                                                           1000
                depths greater than 200 m.
                   Ile Greenland turbot is a large                                                                      -800
                flatfish that may live more than
                20 years and reach sizes as great as         60-                                                         600
                110 cm and 16-17 kg. Spawning                                                       SRA Biomass
                occurs in winter and may be pro-             40 ----                                                     400
                tracted, starting in September or                                                 Catch
                October and continuing until March.          20                                                          200
                Maturity is reached at 5-10 years.
                   The fishery for Greenland turbot                                                         MMMIP
                                                                    72   74   7e
                intensified in the early 1970s with            70                 78   80   82  84   so   Be   go  92
                annual catches reaching a peak of                                        Year


                20                                           BerIng Sea/Aleutian Islands Groundfish Resources















                                                            GPJMNLAND TURBOT
                                                Eastern Bering Sea and Aleutian Islands



                         Average catch (1977-92)                                  =   25,870 t
                         Long-term potential yield (MSY)                          =   27,100 t
                         Exploitable biomass (1992)                               = 292,500  t
                         Acceptable biological catch (1992)                            7,000 t
                         Fishing strategy                                         = Bycatch  only
                         Abundance and trend                                      = Low and  decreasing
                         Status of exploitation                                   = Fully exploited
                         Importance of recreational fishery                       = Non-existent
                         Management                                               - BSAI Groundfish FMP
                         Age/length  at 50% maturity                              = 5-10 years/44-57 cm
                         Age/length  at recruitment                               = 5 years/44 cm
                         Maximum age                                              = At least 20 years
                         Assessment Method                                        = Yield per recruit and
                                                                                     stock reduction analysis

                         M - 0.18     F0. I = 0.062   Fw = 0.08 F1,2     0.001
                         F,97.1_92 - 0-051          F@rftt@@ = 0.068



                  ranging Erom 48,000 to 57,000 L Catches have          in 1979, and again in 1981-82, but a notable absence
                  continued to decline to less than 10,000 t since 1986. of similar-sized fish in later surveys.
                  For 1992, no directed fishery was allowed and            Results of comparative trawling between a U.S.
                  harvest was bycatch only. This decline is primarily   research vessel and Japanese commercial vessels
                  due to catch restrictions placed on the fishery       indicate that the bottom trawl survey of the conti-
                  because of continuing poor recruitment observed       nental slope underestimates the biomass of
                  since 1986.                                           Greenland turbot. Because of this, stock-reduction
                     Results from triennial surveys conducted on the    analysis has been used to estimate the biomass and
                  eastern Bering Sea shelf in 1975 and 1979-92 have     population trend to evaluate the consequences of
                  shown a significant decline in the juvenile popula-   various levels of fishing mortality. Results of the
                  tion. In addition, surveys of the continental slope   analysis suggest that the biomass of Greenland
                  indicated strong recruitment of fish less than 55 cm  turbot has steadily decreased from virgin levels of
                                                                        over I million t in 1960 to 292,500 t in 1993.


                                  GREENLAM TUPJ30T
                     Eastern Bering Sea and Aleutian Islands            For further information
                                 COMMERCIAL CATCH (t)
                                                                        Wilderbuer, T. K and T. M. Sample. 1992.
                    Year     Foreign    Joint Domestic      Total       Greenland turbot. Stock assessment and fishery
                                        Venture                         evaluation document for groundfish resources in the
                    ------------------------------------------          Bering Sea/Aleutian Islands Region as projected for
                    1983       47,554         4       0   47,558
                    1984       23.097       22        0   23,119        1993. North Pacific Fishery Management Council,
                    1985       14,720       11        0   14,731        RO. Box 103136, Anchorage, AK 995 10.
                    1986        6.894       36   2,934      9,864
                    1987        1,048       59   8,479      9,585
                    1988            0       88   7,020      7,108
                    1989            0       50   8,772      8,822
                    1990            0         1  9,618      9,619
                    1991            0         0  6,119      6,119
                    1992            0         0  1,641      1,641




                  Bering Sea/Aleutian Islands Groundfish Resources                                                    21






                  5. ARROWTOOTH FLOUNDER
                  By Terance M. Sample and Thomas K. Wilderbuer











                                                                              



                                                                                                

                                                                                                      

                                                                                                     













                     Affowtooth flounder (Atheresthes stomias) is             fishery. Catches of arrowtooth flounder ranged
                 widely distributed from California to the Gulf of            from 19,000 to 25,000 t during 1974-76. Catches
                 Alaska, and in the central and northern Bering Sea           decreased thereafter to 3,000 t in 1990 and 1991
                 westward to the Asiatic coast.
                 Arrowtooth flounder is a relatively
                 large flatfish species that occupies                    Arrowtooth Flounder
                 continental shelf waters almost                Eastern Bering Sea/ Aleutian Islands
                 exclusively until age 4, and at older
                 ages is found in both shelf and slope       25 Catch (1,000 metric tons)              Biomass (1.000 metric tons) 600
                 waters to depths of 900 in. A
                 maximum length of 84 cm and ages                                                                               
                 of over 15 years have been observed.        20 -                                                            500
                 Spawning probably occurs from                                      Catch
                                                                                           ------                   - --- --- 400
                 December to February in the Bering            15
                 Sea.                                                                                                         300
                    Arrowtooth flounder is similar in        10
                 life history, distribution and exploi-                                                                       200
                 tation to the Greenland turbot. It            5
                 has been an undesirable commercial                                                                           100
                 species and generally has been taken          0                                                              0
                 as by catch in other target fisheries,          70    72   74   76    78   80   82    84   86   88    90   92
                 mainly in the Greenland turbot                                              Year


                 22                                             Bering Sea/Aleutian Islands Groundfish Resources
 














                                                             ARROWTOOTH FLOUNDER
                                                   Eastern Bering Sea and Aleutian Islands



                       Average catch (1977-92)'                                              9,446 t
                       Long-term potential yield (MSY)                                  =  59,000 t
                       Exploitable biomass (1992)                                       = 479,700 t
                       Acceptable biological catch (1993)                               =  72,000 t
                       Fishing strategy                                                   F35%
                       Abundance and trend                                              = High and increasing
                       Status of exploitation                                           = Under-exploited
                       Importance of recreational fishery                               = Non-existent
                       Management                                                       = BSAI Groundfish FMP
                       Age/length  at 50% maturity                                      = Unknown
                       Age/length  at recruitment                                       = Male 4 years/29.6 cm
                                                                                          Female 4 years/30.4 cm
                       Maximum age                                                      = At least 20 years
                       Assessment Method                                                = Yield per recruit

                       M = 0.20      Fo., =0.18   F,_ = 0.41 Fl,,2    0.018
                       F1977-92 = 0-05         F-fishim = 0.25       F35% = 0. 15




                   and were 8,500 t in 1992. This decline is primarily 490,000 t in 1990 and have remained at this level
                   the result of catch restrictions placed on the      through 1992. Trawl surveys conducted in the
                   Greenland turbot fishery and the phasing out of the Aleutian Islands Region have indicated that the
                   foreign fishery in the U.S. EEZ. Arrowtooth         resource also increased there during the 1980s Erorn
                   flounder is underutilized as a commercial species.  40,400 t in 1980 to 125,700 t in 1986. A series of
                      Biomass estimates from bottom trawl surveys on   strong year clams accounts for the increase in
                   the Bering Sea shelf and slope have revealed        abundance and should continue to maintain the
                   moderate increases in arrowtooth flounder abun-     overall population abundance at a high level.
                   dance from 1975 (58,000 t) through 1982 (92,000 t).
                   Significant increases in total biomass have been
                   observed since the early 1980s reaching nearly      For further information

                                                                       Sample, T. M., and T. K. Wilderbuer. 1992.
                                  ARROWTOOTH FLOUNDER                  Arrowtooth flounder. In stock assessment and
                      Eastern Bering Sea and Aleutian Islands          fishery evaluation document for groundfish resources
                                  COMMERCIAL CATCH (t)                 in the Bering Sea/Aleutian Islands Region as
                                                                       projected for 1993. North Pacific Fishery Manage-
                      Year    Foreign    Joint Domestic      Total     ment Council, P.O. Box 103136, Anchorage, AK
                                        Venture                        99510.

                      -----------------------------------------
                      1983      13,880       89        0     13,969
                      1984      9,184       268        0     9,452
                      1985      6,851       507       17     7,375
                      1986      3,462     3,376       65     6f9O3
                      1987      2,789     1,675       75     4,539
                      1988           0    2,574   3,309      5,883
                      1989           0    2,264      958     3,222
                      1990           0      600   3,572      4,232
                      1991           0        0   4,069      4,069
                      1992           0        0   8,516      8,516




                   Bering Sea/Aleutian Islands Groundfish Resources                                                  23






                   6. ROCK SOLE

                   By Thomas K. Wilderbuer and Gary E. Walters



                                                                                                                                    A




                                                                           
                                                              



                                                 
                                                                                                                             A--

                        
                                                                                                                                APF









                                                                                   




                                                                            



                                                                                                                          Photo: AFSC
                      Rock sole (Pleuronectes bqilineatus) is distributed       L. bilinewus peracuata (Cope) of the Gulf of Alaska,
                   from southern California (where it is scarce)                Bering and Okhotsk Seas and L. bilineatus
                   northward to the Bering and Okhotsk Seas and                 mochigaeri Snyder of the northwestern Pacific
                   southward to the Korean peninsula
                   and the Sea of Japan. The largest
                   concentrations are found on the mid-                             Rock Sole
                   Bering Sea shelf, the center of its            Eastern Bering Sea/ Aleutian Islands
                   distribution. Rock sole is a relatively
                                                                  catch (1,000 metric tons)           Biomass (1,000 metric tons)
                   small flatfish that may attain weights     80                                                             2000
                   over 1.5 kg and lengths of 53 cm for                                                     Survey
                   males and 60 cm for females.                                                          Biomass
                   Maximum age is at least 25 years.                                                                          1500
                   Spawning occurs during winter and
                   early spring with 50% sexual                                                      SS Biomas
                   maturity occurring at 29 cm for            40                                                              1000
                   males and 32-33 cm for females, or                     Catch
                   at about 8 years of age. Rock sole is      20                                                              500
                   one of a few species of flatfish with
                   demersal eggs.
                     There are dime subspecies:                  0                                                            0
                   bilineatus bilineata (Ayers) off the            63 65 67 69 71 73 75 77 79  81 83 85 87 89 91
                   West Coast of North America,                                              Year
                          



                                                                  

                   24                                             Bering Sea/Aleutian         Islands Groundfish Resources
 














                                                                     ROCK SOLZ
                                                                 Eastern Bering Sea



                           Average Catch (1977-92)                                         - 22,080 t
                           Long-term potential yield (MSY)                                 - 136,400-184,000 t
                           Exploitable biomass (1992)                                      - 1,500,500 t
                           Acceptable biological catch (1993)                              - 185,000 t
                           Fishing strategy                                                  F350
                           Abundance and trend                                             = High and stable
                           Status of exploitation                                          = Underexploited
                           Importance of recreational fishery                              = Non-existent
                           Management                                                      = BSAI Groundfish FMP
                           Age/length    at 50% maturity                                   = Males 8 years/29 cm
                                                                                             Females 8 years/32-33 cm
                           Age/length    at recruitment                                    = Males 3 years/14.4 cm
                                                                                             Females 3 years/14.3 cm
                           Maximum age                                                     = At least 25 years
                           Assessment Method                                               = Dynamic pool models

                           M - 0.2       Fo., = 0.159    Fmy = 0.176           F1112    0.003
                           F1977-92 = 0-029     F@rftsblw    0.176       F351    0-18




                    Ocean. Commercial catches of rock sole in the              level (40,000 t in 1992) primarily due to the bycatch
                    eastern Bering Sea are managed as a unit stock.            of valuable halibut and crab species taken in the
                       With the advent of the yellowfin sole bottom            pursuit of rock sole. Rock sole is currently
                    trawl fishery in the late 1950s and early 1960s, rock      underutilized with a very low fishing mortality rate.
                    sole catches occurred first as bycatch, but also as a         Biomass of rock sole are estimated Erom bottom
                    target species during the roe-bearing season.              trawl surveys, cohort analysis and stock synthesis
                    Catches peaked at nearly 61,000 t in 1972 and then         modeling. Rock sole biomass was relatively stable
                    declined to low levels until the late 1980s when a         from 1975 to 1979, but then increased substantially
                    valuable domestic rock sole roe fishery developed,         throughout the 1980s from 951,000 t in 1979 to
                    taking over 63,000 t in 1988. Ibis domestic roe            1.5 million t in 1992. Current biomass may be at or
                    fishery is believed to have been worth $25-35 million      above virgin levels.
                    in 1988. Current catches have remained below this             The primary reason for the increase in abundance
                                                                               during the 1980s appears to be the recruitment of a
                                          ROCK SOLZ                            series of strong year classes spawned Erom 1981 to
                         Eastern Bering Sea and Aleutian Islands               1987. Trawl survey estimates of age composition in
                                         COMMERCIAL CATCH (t)                  1991 indicated that 84% of the population numbers
                                                                               were ages 4-8. corresponding to the 1981-87 year
                      Year     Foreign      Joint     Domestic       Total     classes. This strong recruitment should provide an
                                            Venture                            abundant and stable biomass in the near future.

                      -------------------------------------------
                      1983         4,478      9,140          0       13,616    For further information
                      1984        10,156    27,523           0       37,679
                      1985         6,671    12,079           0       18,750    Wilderbuer, T. K., and G. E. Walters. 1992. Rock
                      1986         3,394    16,217           0       19,611
                      1987            776   11,136     14,209        26,121    sole. In Stock assessment and fishery evaluation
                      1988             0    40,844     22,374        63,218    document for groundfish resources in the Bering
                      1989             0    21,010     23,544        44,554    Sea/Aleutian Islands Region as projected for 1993.
                      1990             0    10,492     13,584        24,076    North Pacific Fishery Management Council, P.O.
                      1991             0          0    26,297        26,297
                      1992             0          0    39,314        39,314    Box 103136, Anchorage, AK 99510.



                    Bering Sea/Aleutian Islands Groundfish Resources                                                                25






                 7. OTHER FLATFISH
                 By Gary E. Walters and Thomas K. Wilderbuer





                    The "other flatfish"complex of
                 species is a category of flatfish created                      Flathead Sole
                 for management purposes. This                Eastern Bering Sea/ Aleutian Islands
                 category is made up prunarily of two
                 species, flathead sole                      60 Catch (1.000 metric tons)           Biomass (1,000 metric tons) 700
                 (Hippoglossoides elassodon) and
                                                                                                                                600
                 Alaska plaice (Pleuronectes                 50
                 quadrituberculatus), but also includes
                                                                                                                                500
                 several others such as rex sole (Errex      40                    -----_Survey- Biomas
                 zachirus), Dover sole (Microstontias                                                                           400
                 pacificus), starry founder (Platichthys     30
                 stellatus), longhead dab (Pleuronectes                                                                         300
                                                             20
                 proboscidea), and butter sole                                                                                  200
                 (Pleuronectes isolepis). With the
                 exception of Alaska plaice and              10                                                                 100
                 flathead sole, these species are not         0                                                                   0
                 abundant in the eastern Bering Sea.             63 65 67  69 71 73 75 77 79 81 83 85 87 89 91
                                                                                          Year






                                                                  OTHER FISH
                                                     Eastern Bering Sea and Aleutian Islands



                                                                          Flathead Sole               Alaska Plaice


                           Average catch (1982-91)                        =   5,250 t                22,420 t
                           Long-term potential yield (MSY)                =  65,100 t                76,600 t
                           Exploitable biomass (1992)                     = 650,100 t               562,400 t
                           Acceptable biological catch (1993)             = 105,600 t               77,300 t
                           Fishing strategy                               =   F 356                   F 356   
                           Abundance and trend                            = High and                High and
                                                                            increasing                 stable
                           Status of exploitation                         = Underexploited          Underexploited
                           Importance    of recreational fishery          = None                    None
                           Management                                     = BSAI Groundfish FMP
                           Age/length    at 50% maturity                  = Unknown                 Females
                                                                                                    9 yrs/31 cm
                           Age/length    at recruitment                   = 3 yrs/17 cm             4 yrs/13 cm
                           Maximum age                                    = 20+ years               23+ years
                           Assessment Method                              = Yield per recruit
                           M                                              = 0.2                     0.2
                           F  (0.1)                                       = 0.159                   0.159
                           F  (MSY)                                       = 0.176                   0.176
                           F  (1992)                                      = 0.002                   0.003
                           F  (1977-91)                                   = 0.023                   0.031
                           F  (overfishing)                               = 0.23                    0.2
                           F  356                                         = 0.193                   0.167



                 26                                         Bering Sea/Aleutian Islands Groundfish Resources
 














                                                            OTHER 17,ATFISH
                                                Eastern Bering Sea and Aleutian Islands
                                                        COMMERCIAL CATCH (1,000 t)


                     Category           1982   1983   1984      1985   1986   1987    1988    1989    1990    1991
                     ---------------------------------------------------------------------------------------
                     Flathead Sale
                      Foreign           4.3    4.4    3.6       2.6    0.7    0.2     0       0       0       0
                      Joint Venture     0.2    0.8    0.9       3.1    4.5    3.7     6.8     3.5     2.2     0
                      Domestic          0      0      0         0      0      0.01    0       0.02    9.9     1.1


                     Total              4.5    5.2    4.5       5.7    5.2    3.9     6.8     3.5     12.1    1.1


                     Alaska Plaice
                      Foreign           6.6    9.1    15.1      11.3   6.2    0.8     0       0       0       0
                      Joint Venture     0.2    1.6    3.7       13.6   40.3   17.5    61.7    13.8    15.9    0
                      Domestic          0      0      0         0      0      0.05    0       0.07    4.8     1.8


                     Total              6.8    10.7   18.8      24.9   46.5   18.4    61.7    13.9    20.7    1.8






                  Flathead sole                                        Alaska plaice

                     Flathead sole range from Point Reyes, California,    Alaska plaice range Erom the Gulf of Alaska to
                  along the U.S. West Coast and British Columbia into  the Bering and Chukchi Seas and south into Asian
                  the Gulf of Alaska, Bering Sea, Aleutian Islands,    waters to the Sea of Japan, including the Okhotsk
                  and the Kuril Islands. It is by far most abundant on Sea to as far south as Peter the Great Bay. In the
                  the eastern Bering Sea shelf, occurring at bottom    eastern Bering Sea, where Alaska plaice is most
                  depths between 100 and 250 in. Flathead sole is a    abundant, it is almost entirely limited to continental
                  relatively small-sizod flatfish and may attain lengths shelf waters with a distribution similar to yellowfin
                  up to 49 cm for males and 52 cm for females, and     sole. The highest concentrations are found on the
                  weights of 1.2 to 1.5 kg, respectively. Most females middle shelf area southeast of St. Matthew Island
                  mature by age 2, but whether or not spawning occurs  primarily at depths less than 150 in. Alaska plaice
                  at this age is unknown. Spawning occurs during the   are a relatively large flatfish and may reach a length
                  spring.                                              of 60 cm and an age of over 20 years. Alaska plaice
                     Flathead sole are managed by the NPFMC as one     spawn Erom April to June on hard, sandy substrates
                  stock unit in the Bering Sea. It is of limited com-  with females reaching 50% maturity at 31 cm, which
                  mercial importance and are usually caught as         corresponds to an age of 9 years.
                  bycatch in the yellowfin sole and rock sole (roe)       Commercial fisheries catch information reported
                  trawl fisheries. Catches from 1963 to 1980 averaged  by foreign fleets during the 1960s indicated that
                  18,400 t annually with a peak of 5 1,000 t occurring Alaska plaice was not sought after and was lightly
                  in 197 1. Catches since 1980 have averaged only      exploited. Although not a target species, it is
                  5,070 L Flathead sole are underexploited in the      believed that substantial unreported removals of
                  Bering Sea.                                          Alaska plaice occurred in the intensive yellowfin
                     Bottom trawl surveys conducted by the NNFS in     sole fishery during the 1960s and may have contrib-
                  the eastern Bering Sea indicate that the flathead sole uted to a population decline. In 1975, when Bering
                  resource has increased from 100,000 t in 1975 to     Sea trawl surveys were initiated, Alaska plaice
                  over 650,000 t in 1992. This increase appears to be  biomass was estimated at 103,500 t@ the lowest level
                  the result of a series of consecutive strong year    observed during the time series. Catches since the
                  classes spawned in the late 1970s and early 1980s.   implementation of the Magnuson FMCMA in 1977



                  Bering Sea/Aleutian Islands Groundfish Resources                                                    27










                 have increased to a high of 61,600 t
                 in 1988 and have averaged only                                   Alaska Plaice
                 16,800 t (F = 0.032). Alaska              Eastern Bering Sea/Aleutian Islands
                 plaice are currently underexploited.
                    Bottom trawl surveys indicated             70 Catch (1,000 metric tons)           Biomass (1.000 metric tons) 1000
                 that Alaska plaice biomass increased
                 from a low of 103,500 t in 1975 to            60
                 734,400 t in 1994. Since 1984, the                                                                            800
                 biomass has remained stable between           50          
                 525,000 and 600,000 t.The increase            40                                                              600 
                 during the late 1970s to early 1980s                                                                          400
                 was caused by a series of stronger
                 than average year classes from 1973           20
                 to 1976.                                                                                                      200
                                                               10  
                 For further information                        0                                                                0
                                                                   63 65 67 69 71 73 75 77 79 81 83 85 87  89 91
                 Walters, G. E., and T. K.Wilderbuer.                                     Year
                 1992. Other flatfish. In Stock
                 assessment and fishery evaluation document for
                 groundfish resources in the Bering Sea/Aleutian
                 Islands Region as projected for 1993. North Pacific
                 Fishery Management Council, P.O. Box 103136,
                 Anchorage, AK 99510.




























               28                                            Bering Sea/Aleutian Islands Groundfish Resources
 




                                                         8. PACIFIC OCEAN PERCH

                                                                                         By Daniel H. Ito and James N. lanelU













                                              SIC                                        V)














                       Pacific ocean perch (Sebastes alutus) inhabit the        divided into three subgroups: 1) Pacific ocean
                    outer continental shelf and upper slope regions of the      perch, 2) shortraker and rougheye rockfishes, and
                    North Pacific Ocean and Bering Sea regions. TWo             3) sharpchin and northern rockfish. These
                    main stocks of Pacific ocean perch have been                subgroups were established by the NPFMC to
                    identified in the region--an eastern
                    Bering Sea slope stock and an                               Pacific Ocean Perch
                    Aleutian Islands stock.                                        Eastern Bering Sea
                        For management purposes, four             Catch (1.000 metric tons)             Biomass (1.000 metric tons)
                    other associated species of rockfish       50-                                                               80
                    (northern rockfish, S. polyspinis;
                    rougheye rockfish, S. aleutianus;          40 -
                    shortraker rockfish, S. borealis; and                                                                        60
                    sharpchin rockfish, S. zacentrus) are      30-                                          mass
                    managed as a part of the Pacific                       catch
                    ocean perch complex. For the
                    eastern Bering Sea slope region, the       20 - --
                    POP complex was divided into two                                                                             20
                    subgroups: 1) Pacific ocean perch          10_
                    and 2) shortraker, rougheye,
                    sharpchin, and northern rockfishes          0-1                              015MMM      M'PM9P9Pp   PM,L0
                    combined. For the Aleutian Islands            1960    1965     1970     1975     1980     1985    1990
                    region, the POP complex was                                               Year

                    Bering Sea/Aleutian Islands Groundfish Resources                                                                29















                                                        PACIFIC OCZAN PZRCR
                                             Eastern Bering Sea and Aleutian Islands
                                                        COMMERCIAL CATCH (t)



                                      r.@ctArn Rtgring _qa&L@ @             Aleutian Tqlandn


                         Year      Foreign       JV   DAP      Total    Foreign    JV      DAP      Total
                         --------------------------------------------------------------------------


                         1983         116        97   8        221      272        8                 280
                         1984         156        134  1,279    1,569    356        273     2         631
                         1985         35         32   717      784      Tr         215     93        308
                         1986         16         117  427      560      Tr         160     126       286
                         1987         5          50   875      930      0          500     504       1,004
                         1988         0          51   996      1,047    0          1,513   466       1,979
                         1989         0          31   1,986    2,017    0          0       2,706     2,706
                         1990         0          0    5,639    5,639    0          0       14,650    l4f650
                         1991         0          0    4fO83    4,083    0          0       4,000     4,000
                         1992         0          0    3f540    3,540    0          0       11,700    11,700



                         JV = Joint   Venture                  DAP = Domestic Annual Processing





              protect individual low catch-quota species from        ties generally occurring between 100 and 400 m.
              possible overfishing.                                     Pacific ocean perch are slow-growing and long-
                 Of the five species which comprised the Pacific     lived. Longevity has been estimated at 90 years.
              ocean perch complex, S. alutus has historically been   The natural mortality rate equals 0.05. This species
              the most abundant and has contributed most to the      begins to recruit to the commercial fishery at about
              commercial rockfish catch. Furthermore, the bulk of    age 5 and is fully recruited by age 10, corresponding
              the research on
              rockfish has concen-
              trated on Pacific                                   PACIFIC OCEAN PZRCH
              ocean perch; little                         Eastern  Bering Sea and Aleutian Islands
              biological or
              assessment ifforma-     Average Catch: Eastern Bering Sea (EBS)          -   1,883 t
              tion is available for       (1977-92)       Aleutian Islands (AI)        -   4,108 t
                                      Long-term potential yield: EBS                   -   4f6OO t
              the other species.                                     AI                -  10,300 t
              Consequently, this      Acceptable biological catch (1993): EBS          =   3,300 t
              synopsis deals                                                   AI      -  13,870 t
              primarily with          Exploitable biomass (1993):    EBS               -   59,700 t
                                                                     AI                -  260f3OO t
              Pacific ocean perch.    Fishing strategy                                 ,  F3s%
                 Pacific ocean        Age at recruitment                               -  5-10 years
              perch am usually        Length at recruitment                            =  26-32 cm
              associated with         Maximum age                                      -  90 years
                                      Abundance and trend                              -  Moderate and increasing
              trawlable cobble        Importance of recreational fishery               -  None
              submate. A              Management                                       -  BSAI Groundfish FMP
              demersal species, it    Status of exploitation                           -  Fully exploited
              can be found at         M = 0.05             Fo.@ = 0.06           FWY    0.06
              depths ranging from     F@rf"U" = unknown        F1977_92≀&g* = <0*06
              50 to 700 in, with
              commercial quanti-

              30                                       Bering Sea/Aleutian Islands Groundfish Resources







                     with fork lengths of about 26 and                              Pacific Ocean Perch
                     32 an, respectively. Although the                                    Aleutian Islands
                     maximum recorded length is 54 cm,
                     the bulk of the commercial catch is                 Catch (1,000 metric tons)          Biomass (1,000 metric tons)
                     comprised of individuals ranging from        120--                                                               400
                     25 to 45 cm. Females are viviparous,          100-        -
                     retaining eggs in the ovary after                              -Catch-
                     fertilization until the yolk sac is           80--
                     absorbed. Mating takes place in late
                     Eall or early winter, with subsequent                                                                         ___200
                     Larval extrusion occurring in late
                     winter or early spring.                        40---
                         Very little biological information is
                     available for the four other species           20-
                     within the POP complex. Preliminary
                     information suggests, however, that             0-                                                             -0
                     they are also slow-growing and long-                1960   1965   1970     1975     1980     1985     1990
                     lived. Maximum reported ages for           I                                 Year
                     rougheye and shortraker rockfish are
                     140 and 120 years, respectively. Natural mortality is          more than 90-95% from those of the early 1960s,
                     probably about 0.05 or less, suggesting very low               suggesting a depressed stock condition. Since then,
                     rates of productivity.                                         the stocks have shown signs of rebuilding.
                         Pacific ocean perch were highly sought after by              Based on results from comprehensive age-
                     Japanese and Soviet fisheries and supported a major            structured modeling (stock synthesis), the current
                     trawl fishery throughout the 1960s and early 1970s.            (1993) estimate of exploitable biomass for Pacific
                     Catches in the eastern Bering Sea peaked at 47,000 t           ocean perch is 59,700 t for the eastern Bering Sea
                     in 1961; the peak catch in the Aleutian Islands                stock and 260,300 t for the Aleutian Islands stock.
                     region occurred in 1965 at 109,100 L Soon after, the           The stock in the eastern Bering Sea appears to have
                     catches declined rapidly. With such long life spans            stabilized, whereas, the Aleut= Islands stock
                     and low rates of natural mortality and growth,                 appears to be increasing in abundance. The most
                     Pacific ocean perch were apparently unable to                  recent estimates of exploitable biomass for the other
                     sustain such Large removals from their populations.            four species in the complex are 29,700 t in the
                         With the implementation of the MFCMA in                    eastern Bering Sea and 139,500 t in the Aleutian
                     1977, the foreign fisheries were gradually phased              Islands. In both regions, recent analyses have
                     ouL Coincident with this reduction in foreign                  concluded that the recruitment of Pacific ocean
                     fishing, a significant domestic rockfish fishery               perch is highly variable.
                     developed. The domestic fishery started out as joint
                     ventures with foreign companies in the mid- 1980s
                     and has now become a totally domestic industry.                For further information
                     The domestic fishery is primarily composed of
                     factory trawlers that harvest and process the fish at          lanelli, J.N., and D.H. Ito. 1992. Pacific ocean
                     sea. Although Pacific ocean perch has been the                 perch. In Stock assessment and fishery evaluation
                     primary target of the rockfish fishery, recent fisheries       document for groundfish resources of the Bering
                     also target on shortraker and rougheye rockfish.               Sea/Aleutian Islands region as projected for 1993.
                     These species are larger than Pacific ocean perch              North Pacific Fishery Management Council, P.O.
                     and inhabit deeper waters (>300 m) of the continen-            Box 103136, Anchorage, AK 99510.
                     tal slope.
                         Stock assessments based on catch-per-unit-effort
                     (CPUE) data from Japanese trawlers indicate that
                     stock abundance declined to very low levels in all
                     regions. By 1977, CPUE values had dropped by


                     Bering Sea/Aleutian Islands Groundfish Resources                                                                    31





                        OTHER ROCKFISH

                By Dankl H. 1W



                   'Me category "other rockfish",                                   Other Rockf ish
                includes Sebastolobus SM. and a                                     Eastern Bering Sea
                species of Sebastes other thari the
                Pacific ocean perch complex. For              3000 Catch (metric tons)                   Biomass (1,000 metric tons)
                management purposes, the other
                rockfhsh resource is assumed to               2500-                                                            - 10
                consist of two separate groups: the
                eastern Bering Sea group and the              2000-         Catch                   Biomass
                Aleutian Islands group. Informa-
                tion on biological parameters is              1500-
                lacking for these groups of rock-
                fishes.                                       1000-                                                            - 4
                   Since implementation of the
                NFCMA, the peak catch (2,600 t)               500-                                                             -2
                of other rockfish in the eastern ,
                Bering Sea occurred in 1978. In                 0                                                        E, 0
                the Aleutian Islands region, the                 1977 1979       1981  1983 1985 1987 1989            19 91 1993
                peak removal occurred I yew later                                              Year
                in 1979 with a harvest of about
                4,500 L Catches in recent years have been minor                biomass. The best estimate of current exploitable
                and are mainly incidental to other directed fisheries.         biomass for other rockfish is about 8,000 t for the
                Ile average catch during 1977-91 amounted to                   eastern Bering Sea stock and 18,500 t for the
                about 560 t from the eastern Bering Sea region and             Aleutian Islands stock. The estimates, however,
                1,000 t from the Aleut= Islands region.                        have very wide confidence intervals.
                   Cooperative U.S.-Japan trawl surveys conducted                   Information is not available to estimate MSY.
                from 1979 to 1988 provided the estimates of absolute           However, if one assurnes that the exploitation and


                                                                      OTEZR ROCKFISH
                                                        Eastern Bering Sea and Aleutian Islands
                                                                     COMMERCIAL CATCH (t)



                                                                                               Alpiitfan Tnlandq


                        Year     Foreign         JV       DAP        Total          Foreign    JVP       DAP        Total

                        1983           212       8        --         220            1,041      4                    1,045
                        1984           121       8        47         176            42         14        --         56
                        1985           33        3        56         92             2          14        83         99
                        1986           4         12       86         102            Tr         15        154        169
                        1987           3         4        467        474            0          6         141        147
                        1988           0         8        333        341            0          68        210        278
                        1989           0         4        188        192            0          0         481        481
                        1990           0         0        384        384            0          0         864        864
                        1991           0         0        328        328            0          0         541        541
                        1992           0         0        376        376            0          0         699        699



                        JVP      Joint   venture              DAP    Domestic annual processing
                                                                  i
                                                                            Catch














































                32                                             Bering Sea/Aleutian Islands Groundfish Resources







                        productivity patterns for other rockfish                                   Other Rockfish
                        are similar to those of S. alutus, LTPY
                        has beeen estimated at about 400 t for                                      Aleutian Islands
                        the eastern Bering Sea and 900 t for               5 Catch (1,000 metric tons)                     Biomass (1,000 metric tons)  25
                        the Aleutian Islands region.
                           It is assumed that the same
                        exploitation rate used to estimate the             4                                           Biomass                        20
                        ABC for Pacific ocean perch (S.
                        alutus) is applicable for estimating               3                                                                           15
                        ABC for other rockfish. Multiplying
                        M equals 0.05 by the current exploit-                                 Catch
                        able biomass, yields ABC values of                  2                                                                          10
                        400 t for the eastern Bering Sea stock
                        and 925 t for the Aleutian Islands                  1                                                                       -5
                        stock.


                                                                              1977    1979    1981     1983    1985    1987     1989    1991     1993
                                                                                                              Year



                        For further information


                        Ito, D.H. 1992. Other rockfish. In Stock assess-
                        ment and fishery evaluation document for groundfish
                        resources of the Bering Sea/Aleutian Islands region
                        as projected for 1993. North Pacific Fishery Man-
                        agement Council, P.O. Box 103136, Anchorage, AK
                        99510.







                                                                                            OTHM ROCKFISH
                                                                 Eastern Bering Sea (EBS) and Aleutian Islands                     (AI)



                                                      Average catch: Eastern Bering Sea (EBS)                                550   t
                                                           (1977-92)       Aleutian Islands (AI)                             980   t
                                                      Long-term potential yield: EBS                                         400   t
                                                                                            AI                               900   t
                                                      Acceptable biological catch (1993):                EBS                 400   t
                                                                                                          AI                 925   t
                                                      Exploitable biomass (1993): EBS                                =     8,000   t
                                                                                             Al                      =  18,500     t
                                                      Fishing strategy                                               =  F = M
                                                      Age/length at recruitment                                      =  Unknown/unknown
                                                      Maximum age                                                    =  Unknown
                                                      Abundance and trend                                            =  Unknown
                                                      Importance of recreational fishery                             =  None
                                                      Management                                                     =  BSAI Groundfish FMP
                                                      Status of exploitation                                         =  Unknown

                                                      M = Unknown             F0.1 =  Unknown Fmr = Unknown
                                                      F_f,hi'n = Unknown              F1977_92 awrag. = Unknown



                        Bering Sea/Aleutian Islands Groundfish Resources                                                                                33





                  10. ATKA MACKEREL

                  By Sandra A. La we














                                                                A



















                                                                                                                        Photo: AFSC
                     Atka mackerel Pleurogranunus monopterygius is             Atka mackerel of the Gulf of Alaskyk and the
                 a semidemersal species. The species is found from          Aleutian Islands region are thought to belong to
                 the east coast of the Kamchatka Peninsula, through-        separate stocks. Commercial fisheries for Atka
                 out the Komandorskiye and Aleutian Islands, north          mackerel in the Bering Sea/Aleutian Islands region
                 to the Pribilof Islands in the eastern
                 Bering Sea, and eastward through                                 Atka Mackerel
                 the Gulf of Alaska to Southeast                     Eastern Bering Sea/Aleutian Islands
                 Alaska. Its center of abundance is
                 in the Aleutian Islands. Aft              50 Catch (1,000 Metric tOnS)
                 mackerel range from the lower
                 inteWdal area to depths of 575 m.
                 but over 95% of their occurrences
                 have been at depths less than 300         30
                 m. Both sexes mature at 3-4 years
                 of age at a size of 31-33 cm. Atka
                 mackerel commonly attain sizes up         20
                 to 45 cm and 1. 1 kg in weight. The
                 maximum age is 14 years, although         10
                 the bulk of the catch has consisted
                 of fish 3-7 years old. Spawning             0                                  @6       88      90      92
                 generally occurs during June-                 78      80       82      84
                 September at depths of 5-30 m.                                            Year
                                                                                                                               1

                 34                                           Bering Sea/Aleutian Islands Groundfish Resources
















                                                              ATKIL XACKEREL
                                                 Eastern Bering Sea and Aleutian Islands



                           Average catch (1978-92)                                         25,900 t
                           Long-term potential yield (MSY)                                  Unknown
                           Acceptable biological catch (1993)                             117floo t
                           Age/length at recruitment                                      3 years/30 cm
                           Maximum observed age                                           14 years
                           Abundance and trend                                            High, stable
                           Exploitable biomass                                            High
                           Harvest strategy                                               F = M
                           Importance of recreational fishery                           = None
                           Management                                                   = BSAI Groundfish FMP
                           Assessment  Method                                           = Age structured
                           Status of exploitation                                       = Underexploited

                           M = 0.30     FO., = 0.324    FN2Y = Unknown

                           F-rfishim = 0.506     F1077-02 aw @ 0,027




                   are managed under the NPFMC's Bering Sea-            exploitable biomass for 1993 of approximately
                   Aleutian Islands groundfish FNT. In the Gulf of      1.2 million t. In addition, it predicts good recruit-
                   Alaska, Atka mackerel are less abundant and are      ment from the 1988 and 1989 year classes in order to
                   included within the "other species" category for     produce the level of biomass seen in the 1991 survey.
                   management under the Gulf of Alaska groundfish       Length frequency and age composition data from the
                   FMP. This species is not an important recreational   1991 survey corroborated the presence of a strong
                   species.                                             1988 year class; however, this year class was not yet
                      Until 1980, Atka mackerel was harvested by        apparent in the commercial fishery. Good recruit-
                   foreign fisheries. U.S. joint venture fisheries then ment combined with low levels of exploitation
                   dominated the catches from 1982 to 1988. Since       indicate that the stock is in good shape and at a high
                   then, the fishery has become exclusively domestic.   abundance level.
                   From 1979 to 1982 catches declined gradually            An estimate of a stock-recruitment relationship is
                   (23,300 t to 19,900 t), then dropped sharply to      required to calculate MSY and its corresponding
                   11,700 t in 1983. The decline was due to changes in  fishing mortality rate U@@. Although there is
                   the target species and allocation issues rather than recruitment information for Atka mackerel, a stock-
                   changes in stock abundance. From 1984 to 1987,       recruitment relationship could not be inferred from
                   catches were at record high levels, averaging        the data. MSY is therefore unknown. As an
                   34,000 t annually. A strong 1977 year class, which   alternative to F a yield-per-recruit model was used
                   recruited to the fishery in 1980, supported e fishery                   level. The F.., level was
                                                          th            to deterinine; the 0.,
                   throughout the 1980s. The commercial fisheries can   determined to equal 0.324. Another study found that
                   occur year-round, but the peak of the fishery has    when uncertainty is directly incorporated into the
                   generally been from April to August. In 1992, Atka   estimation of stock abundance and recruitment, the
                   mackerel landings totaled 46,400 t and had an ex-    optimal fishing mortality rates would be less than
                   vessel value of $12.8 million.                       those derived from deterministic models for sustain-
                      Atka mackerel occur in large, localized concen-   able yield (e.g., FO.). A lower harvest rate of 30%
                   trations making them an especially difficult species (F = M) was therefore recommended and multiplied
                   to survey with trawls. They are also difficult to    by exploitable biomass to obtain an ABC of 351,300
                   survey with hydroacoustic gear because they are poor L Because of uncertainties in the estimation of
                   acoustic targets. Because of survey difficulties, a  biomass, the NPFMC decided to step up the use of
                   stock synthesis model was used to assess the status of the available ABC in 6 equal increments (58,550 t),
                   Atka mackerel. The model projected a high level of   beginning with the 1992 fishery. Thus, the ABC for

                   Bering Sea/Aleutian Islands Groundfish Resources                                                       35







                the 1993 fishery was                                      ATKA NZCKEREL
                117,100 L The fishing                       Eastern Bering Sea and Aleutian Islands
                mortality associated with a                            COMMERCIAL CATCH (t)
                catch of 117, 100 t is 0.073;
                well below the overfishing
                level. The overfishing level    Year         Foreign           Joint         Domestic         Total
                                                                               Venture
                is defined as the fishing       -------------------------------------------------------------
                mortality rate that results in  1983        1,214              10,512               0       11,726
                the biomass-pa-recruit ratio    1984          112              35,943               0       36,055
                falling to 30% of its pristine  1985             1             37,859               0       37,860
                                                1986             6             31,984               0       31,990
                level. This rate has been       1987             0             30,061               0       30,061
                determined to be F = 0.50( )    1988             0             19,620           2,465       22,084
                and is associated with a        1989             0                  56        17,938,       17,994
                harvest level of 771,100 L      1990             0                  0         22,205        22,205
                                                1991             0                  0         22,840        22,840
                  The ABC of 117, 100 t is      1992             0                  0         46,226        46,226
                based on an analysis for the
                entire Aleutian region. The
                bulk of the fishery occurs in
                the eastern Aleutian Islands region, whereas the bulk
                of the biomass has been found in the western region,
                particularly the southwest region. To avoid localized
                depletion of the resource, the catch should be
                apportioned throughout its range according to the
                distribution of biomass. Because of administrative
                inability to apportion catches in the Aleutian
                management district at this time, the 1993 TAC for
                the entire Aleutian Islands region was set at only
                32,000 t, an amount appropriate only for the eastern
                portion of the Aleutian Islands region where most of
                the fishing occurs. An amendment to the FMP has
                already been submitted to divide the Aleutians into
                three subareas so that catch quotas can be assigned
                to spread out the fishing effort in future years.



                For further information


                Lowe, S. A. 1992. Atka mackerel. In Stock
                assessment and fishery evaluation document for
                groundfish resources in the Bering Sea/Aleutian
                Islands region as projected for 1993. North Pacific
                Fishery Management Council, P.O. Box 103136,
                Anchorage, AK 99510.

                Methot@ R. D. 1990.. Synthesis model: An adaptable
                framework for analysis of diverse stock assessment
                data. INPFC Bull. 50:259-277.







                36                                     Bering Sea/Aleutian Islands Groundfish Resources





                                        11. SQUID AND OTHER SPECIES

                                                                                                                    By Loh-Lee Low





                                                           T











                                                    -71  V






                      E"


                      L


                                                                                                        N
                                  1k.
                                                                       Ak
                           /All          Ir 1 7     T            'f    'a          a-          -V t   r           V7 V 11   11 V

                                                                                                                          Photo: AFSC
                     Squid                                                          Squid were ocassionally targeted by foreign
                                                                                fisheries in the paSt. During these periods, catches
                     Two species of squid are harvested: the red squid          peaked at 9,000 t in 1978. Following 1985, as
                     (Berryteuthis magister) in the eastern Bering Sea,         foreign fisheries got phased out of the U.S. EEZ and
                     and the boreal clubhook squid
                     (Onychoteuthis borealijaponicus) in                             OTHER SPECIES
                     the Aleutian Islands region. Both                    Eastern Bering Sea/ Aleutian Islands
                     species am distributed across the
                     North Pacific Ocean from Asia to                 Catch (1.000 metric tons)           Biomass (1,ooo metric tons)
                     North America. The red squid is               140--
                     more northerly distributed, being             120---
                     found throughout the Bering Sea                                                                             800
                     north to the Bering StraiL The                100----
                     northward distribution of the boreal                                                      S U tvle          600
                     clubhook squid is limited to the               80
                     southern Bering Sea. Both species              60-
                     inhabit pelagic waters.                                                                                   -400
                        The life span of the two species is         40 ----Catch
                     about a year. The red squid reaches a                                     . . .
                     maximum mantle length of 25 cm;                20
                     the boreal clubhook squid reaches a             0                                                           0
                     maximum mantle length of 37 cm in                 65        70        75         so        85        90
                     females and 30 cm in males.                                                  Year

                     Bering Sea/Aleutian Islands Groundfish Resources                                                                3







                 replaced by U.S. fisheries, catches of squids dropped                            sgu= and OMMR SPXCXZB
                 to a few hundred tons annually, mainly as incidental                      Eastern Bering Sea and Aleutian Islands
                 catches.                                                                            COMMERCIAL CATCH
                     Assessment data for squid are not available
                 bemuse little research has bm di=ted to iL The                    Year     Foreign joint-venture Domestic       Total
                                                                                   -------- ---------------------------------
                 squid resource is believed to be large because of its             SQUID (in t)
                 low position in the trophic chain and light degree of             1983      3,970             10          0     3,980
                 exploitation. MSY and ABC for squid are unknown                   1984      3,133             34          0     3,167
                 but am believed to be at least equal to the highest               1985      1,588             32          0     1,620
                                                                                   19:6           830          38          0       868
                 catch on record (10,000 t).                                       19 7           96           35          1       132
                                                                                   1988           0        171          246        417
                 Other Species                                                     1989           0        107          199        306
                                                                                   1990           0            0        626        626
                                                                                   1991           0            0        632        632
                     The "other species" category covers species that              1992           0            0        544        544
                 are currently of little economic value and not                    OTHER SPECIES (in t)
                 targeted upon but have potential economic value or                1983      14,255     1,578          3,307    19,140
                 are important components of the ecosystern. The                   1984      7,533      2,645                   10,178
                 taxonomic groups are sculpins (Couidae), skates                   1985      6,283      6,343           927     13,553
                 (Rajidw), smelts (0smeridae), sharks (Squalidae)                  1986      4,044      7,557           379     11,980
                                                                                   1987      2,673      6,121           930      9,724
                 and octopus (Octopodidae). There were 38 species                  1988           0     11,840          803     12,643
                 of sculpins identified in the Bering Sea/Aleutian                 1989           0     4,696           405      5,101
                                                                                   1990           0            0      20,808    20,808
                 Islands region. At least five species of skates, dM               1991           0            0      17,199    17,199
                 species of sharks, thm species of smelts, and two                 1992           0            0      22,154    22,154
                 species of octopus am found in this region.
                     Catches of "other species" increased during the
                 1960s and early 1970s reaching a peak of 133,000 t            well below its biological productivity. Based on
                 in 1972. Catches declined to a low of 5,000 t in              average catches, MSY and ABC are both estimated
                 1989 as domestic fisheries displaced foreign and              at 62,900 L Ile NPFMC has set its ABC at 27,200 t
                 joint-venture fisheries. Catches have since stabilized        for 1992 and 26,600 t for 1993 to accomodate
                 at 17,000 - 22,000 t during 1990-92.                          expected catches by the fisheries.
                     Stock assessments of the "other species" category
                 are based on trawl survey data. The data show that            For further information
                 the main species taken by bottom trawls are sculpins
                 and skates. These two groups comprise 95-99% of               Bakkqlq R. G. 199 1. Squid and other species, p. 3 1-
                 the total biomass of the "other species" category             32. In Loh-Lee Low [ed.]. Status of living marine
                 since 1981. Some other species, however, are                  resources off Alaska as assessed in 1991. U.S. Dep.
                 believed to be poorly sampled by bottom trawls,               Commer., NOAA Tech. Memo. NUFS-F/NWC-211.
                 particularly those distributed
                 inshore and in the pelagic zone.                                         OTHER SPECIES
                     Surveys indicate that sculpins                       Eastern Bering Sea and Aleutian Islands
                 were the largest component of the
                 category until 1986, when skate          Average catch (1977-92)                               27,200 t
                 biomass increased and exceeded           Long-term potential yield (MSY)                       62,900 t
                 that of sculpins. The increase           Exploitable biomass (1993)                           780,000     t
                 resulted in higher total biomass         Acceptable biological catch (1993)                    26,600     t
                 for the "other species" category:        Fishing strategy                                      F - M
                 from 345,OW-460,OW t in 1979-            Abundance and trend                              =   High and    increasing
                                                          status of exploitation                           =   Underexploited
                 81 to 632,000-827,OW t in 1988-          Importance of recreational fishery               =   None
                 90.                                      Management                                       =   BSAI Groundfish FMP
                     Ile condition of the resource        Assessment     Method                            =   Survey biomass
                 appears good and exploitation is


                 38                                             Bering Sea/Aleutian Islands Groundfish Resources





                                                                12. WALLEYE POLLOCK

                                                                                                             By Anne D. HoHowed





                                                       Wt




                                                                                                      W.



                         PV
                                                                           A


                                                                                                                        F@





                                                              A


                                                                            up-







                                                                                                                         PhotD: AFSC
                         Walleye pollock (Theragra chalcogramma) is a            pollock are found primarily in the NPFMC's central
                     semidemersal schooling fish that is widely distrib-         and western regulatory areas (long. 147o-l7OoW).
                     uted throughout North Pacific temperate and                 Pollock from these regions are managed as a unit
                     ;subarctic waters. Pollock consume a wide variety of        stock because they are considered separate from
                     prey in the Gulf of Alaska. In 1990,
                     euphausiids, shrimp, and capelin                              Walleye Pollock
                     (Mallotus villosus) were the                                     Gulf of Alaska
                     principal prey items (by weight)              Catch (1,000 metric to'ns)      Biomass (1,000 metric tons)
                     consumed by pollock during the            350-                                                            5000
                     Summer months. Pollock can attain
                     lengths of 80 cm; however, the
                                                                                                                             -4000
                     majority of mature pollock range          250---
                     between 40 and 65 cm in length.                                      Blom&
                     'Me maximum age recorded for              200--                                                         -3000
                     Gulf of Alaska pollock is in excess
                                                               150--
                     of 18 years, although most pollock                                                                      -2000
                     me less than I I years old. Sexual        100-
                     maturity is attained between ages 3                                                                     -1000
                         L:->- VU


                                                                            J




                     ito 6; spawning occurs during the           so-
                     -winter and early spring.                   0                                                         1 -0
                         In the Gulf of Alaska, major              1975 1977 1979 1981     1983  1985 1987 1989 1991 1993
                     exploitable concentrations of           I                                Year

                     ,Gulf of Alaska Groundfish             Resources                                                               39






                 those in the Bering Sea,                                           NALLEYE POLLOCK
                 the Aleutian Islands                                                Gulf of Alaska
                 region, and the eastern                                             CATCH (1,000 t)
                 Gulf of Alaska.
                    Shelikof Strait is a
                 major pollock spawning           Year             Foreign               JVP               DAP                Total
                                                  ------------------------------------------------------------------
                 am in the Gulf of
                 Alaska, although other           1983               81.4              134.1               0.1                215.6
                 spawning locations in            1984               99.3              207.1               0.3                306.7
                 the western and central          1985               31.6              237.9               15.4               284.9
                                                  1986               0.1               62.6                21.3               84.0
                 areas have been identi-          1987               0.0               22.8                39.2               62.0
                 fied from the occurrence         1988               0.0               0.2                 55.8               56.0
                 of eggs and larvae as            1989               0.0               0.0                 72.5               72.5
                 well as observations of          1990               0.0               0.0                 77.8               77.8
                                                  1991               0.0               0.0                 83.3               83.3
                 spawning fish. In                1992               0.0               0.0                 83.2               83.2
                 previous years, these
                 areas were judged to be
                 of minor importance
                 relative to the Shelikof Strait spawning area.                surveys of Shelikof Strait, and commercial fisheries.
                    Triennial bottom trawl surveys of the Gulf of              Age structures were collected from fish by port
                 Alaska and annual hydroacoustic surveys of Shelikof           samplers and domestic observers. Age-composition
                 Strait during the spawning period (March) are                 estimates indicate that the 1984, 1985, and 1988
                 conducted by the AFSC. Biomass estimates based                year classes were predominant in 1992.
                 on bottom trawl surveys show a stable biomass trend,             The stock-synthesis model was used to assess the
                 whereas hydroacoustic surveys show a sharp decline.           status of the Gulf of Alaska pollock stock in 1992.
                 The 1990 biomass estimate from the summer bottom              This model combines the analysis of catch, abun-
                 trawl survey was 766,948 t for the western and                dance, and age-composition data. The fisheries data
                 central regulatory areas combined. The 1990                   set used in the analysis consisted of estimates of total
                 hydroacoustic survey assessed the pollock biomass in          catch biomass and the age composition of the catch
                 Shelikof Strait and areas throughout the Gulf of              aggregated over all seasons, nations, vessel classes,
                 Alaska from Prince William Sound to Davidson                  and statistical areas for years 1976-92. Fishery-
                 Bank. Most of the survey effort outside Shelikof              independent data sets were incorporated into the
                 Strait was concentrated between the 100 and                   stock-assessment procedure to help calibrate the
                 500 fathom contours. The 1990 hydroacoustic                   resulting abundance estimates to the appropriate
                 biomass estimate for Shelikof Strait was 381,594 L            population level.
                 The hydroacoustic estimate of the biomass outside of            A simulation model was constructed to evaluate
                 Shelikof Strait excluding Prince William Sound, was           the long-term impact of various harvest strategies on
                 102,271 L A biomass estimate for Prince William               Gulf of Alaska pollock. This model incorporated
                 Sound was not available. Hydroacoustic surveys of             process error in our knowledge of the spawner-
                 Shelikof Strait show an increase in spawning                  recruit relationship and measurement errors in our
                 biomass from 382,397 t in 1991 to 580,000 t in                ability to assess the stock. An objective function was
                 1992.                                                         developed for the model that balanced increased
                   The entire pollock TAC in the Gulf of Alaska has            yield against the risk of the spawner stock biomass
                 been allocated to domestic fisheries since 1988. The          falling below a threshold level set at 20% of the
                 1991 and 1992 pollock quotas allocated for the                pristine spawner stock biomass. Two recruitment
                 western and central regions were 100,000 t and                scenarios were evaluated. The long-term expected
                 84,000 t, respectively. In 199 1, the TAC was divided         yield under a conservative recruitment scenario was
                 into four equal quarterly allocations for each of the         169,000 L
                 NPFMC regulatory areas.                                         Projections of 'Gulf of Alaska pollock biomass
                   Recent information on the age composition of the            and yield have been made for fish age 3 and older for
                 Gulf of Alaska pollock stock was available from the           the period 1993-95. When fishing mortality is at the
                 bottom trawl surveys, the spring hydroacoustic                optimal level, and conservative assumptions regard-

                 40                                                            Gulf of Alaska Groundfish Resources










                   ing recruitment
                   were used, the 1993                                                 POLLOCK
                   yield would be                                            Gulf of Alaska
                   203,OW t for the
                   western and central     Average catch (1977-92)                            = 129,900 t
                   regulatory arm.         Long-term potential yield                          = 169,000 t
                                           Acceptable biological catch (1993)                 = 160,000 t
                   'Me NPFMC set the       Exploitable biomass (1993)                         = 1,087,000 t
                   TAC (I I LOW t)         Harvesting strategy                                = F = 0.15
                   and ABC                 Age/length at recruitment                          = 3 yrs/30 cm
                   (157,OW t) well         Age/length at 50% maturity                         = 4-5 yrs/39-45 cm
                                           Maximum age                                        = 18+ yrs
                   below 203,WO L          Abundance and trend                                = Low and stable
                   An additional 3,400     Importance of recreational    fishery              = Minor
                   t was allocated for     Management                                         = GOA Groundfisb FMP
                   the eastern regula-     Assessment  Method                                 = Stock synthesis
                   toryarea.               Status of exploitation                             = Below overfishing level
                      The overfishing      M - 0.30                 F1,9,   0. 15             F-erfi.hing = 0.30
                   level for pollock in    F0.1 = 0.28              F33%    0.25              Fogy   0.28
                   the Gulf of Alaska
                   was based on the
                   F,,. The 1993
                   overfishing level was 286,000 t for the western and
                   central areas combined. The overfishing harvest
                   level for the eastern regulatory area was 7,880 L

                   For further information


                   Hollowed, A. B., and B. A. Megrey. 1990. Walleye
                   pollock. In Stock assessment and fishery evaluation
                   document for the 1991 Gulf of Alaska groundfish
                   fishery, p. 22-89. North Pacific Fishery Nfanage-
                   ment Council, P.O. Box 103136, Anchorage, AK
                   99510.
























                   Gulf of Alaska Groundfish Resources                                                                     41





                   13. PACIFIC COD

                  By HaroN H. Zenger, Jr.




                      Pacific cod (Gadus
                  nwcrocephalus) occur on the                                           Pacific Cod
                  continental shelf and upper slope                                    Gulf of Alas@a
                  along the coasts of the United States            Catch (metric tons)                        Biomass (1,000 metric tons) -600
                  and Cana& north of lat. 340N and             100
                  throughout the Gulf of Alaska,
                  Aleutian Islands, and eastern                                                                                   -400
                  Bering Sea to Norton Sound.                    60-------                                                        -300
                  Pacific cod tend to migrate long
                  distances, resulting in an intermix-          40                                                                -200
                  ing of the stocks between some                20                                                                -100
                  regions. Thus the stocks from the
                  Gulf of Alaska, Bering Sea, and                0 9-77RII                                                        -0
                  Aleutian Islands regions am                        77     79      81       83     85        87   89      91
                  genetically indistinguishable. For                                            Year
                  management purposes, the stocks                        Foreign                       joint venture
                  am managed as two seperate units                 E2    Domestic                      survey Biomass
                  according to their major areas of         I
                  concentration - the Gulf of Alaska
                  and Bering Sea-Aleutiazi Islands region.                           During the phase of foreign fishing in the 1970s
                     Gulf of Alaska Pacific cod feed on a wide variety           to the mid- 1980s, the Pacific cod fishery was
                  of crustaceans and fish and rarely reach 95 cm in              dominated by Japanese longline operations. The
                  length or 7 kg in weight. Maximum age of cod in                foreign catch peaked in 1981 at 35,000 t and ended
                  this area is 15 years, but accurate ageing of the older        in 1987. There was also a relatively small joint
                  fish is difficult. Sexual maturity is reached at about         venture fishery operating at that time; it peaked in
                  age 5. Spawning occurs during late winter and early            1984 and ended after 1988.
                  spring.
                    Ile total Pacific cod catch in
                  the Gulf of Alaskii was 74,000 t in                                  PACIFIC COD
                  1992, down 8% from 81,000 t in                                      Gulf of Alaska
                  199 1. Trawlers caught 68% of the
                  total 1991 cod landings; longline         Average catch (1977-92)                           =34,450 t
                  and pot fisheries landed 23% and          Long-term potential yield (MSY)                   =Unknown
                  9%, respectively. Ex-vessel value         Acceptable biological catch (1993)                =56,700 t
                  of the catch was $38A million in          Exploitable biomass (1993)                        =387,700 t
                  1992, down 8% from                        Harvesting strategy                               =FO.1
                                                            Age/length at recruitment                         =3 yrs/45 cm
                  $41.7 million in 199 1. Catches by        Age/length at 50* maturity                        =5 yrs/60 cm
                  recreational fisheries am insignifi-      Maximum age                                       =15+ years
                  canL The catch reached a                  Assessment Method                                 =Age-structured Model
                  historical high proportion of             Importance of recreational         fishery        =Insignificant
                                                            Management                                        =GOA Groundfish FMP
                  groundfish landings in 1991 when          Status of exploitation                            =Fully exploited
                  it comprised 35% of all Gulf of           Abundance and trend                               =Moderate & declining
                  Alaska groundfish landings. In            M = 0.29          F0.1 = 0.18          FK5Y =     F_flhj@w = 0.18
                  1992, however, the composition            F_ = 0.32            E29$6-92.--g.    0*096
                  dropped to 28% of total ground-
                  fish landings.


                  42                                                           Gulf of Alaska Groundfish Resources











                      The assessement of
                    the stocks is based mainly                                  PACIFIC COD
                                                                               Gulf of Alaska
                    on trawl survey infozma-                                 COMMERCIAL CATCH (t)
                    tion. The surveys were
                    conducted by the NMFS           Year           Forei'gn          JV             Domestic           Total
                    every third year, that is     ------------------------------------------------------------------
                    1994, 1987, and 1990.           1983           29,777           2,416             4,198            36,401
                    Estimates of exploitable        1984           15,896           4,649             3,231            23,776
                    biomass (cod older than         1985           9,086            2,266             2,954            14,306
                    age 3) from these surveys       1986           15,211           1,357             8,045            24,612
                                                    1987           0                1,978             29,454           31,432
                    were 570,OW t in 1984,          1988           0                1,661             30,896           32,557
                    559,000 t in 1987, and          1989           0                0                 41,676           41,676
                    390,000 t in 1990. The          1990           0                0                 74,647           74,647
                    higher biomass in the           1991           0                0                 80,974           80,974
                    1980s was due to the            1992           0                0                 74,426           74,426
                    presence of the exception- I
                    ally large 1977 year class.
                    Since then, year classes have been considerably
                    weaker. With continued full fishing pressure and
                    weaker recruitment in recent years, the resource is
                    expected to continue to decline.

                    For further information


                    Zenger, H. H., and G. G. Thompson. 1992. Pacific
                    cod la Stock assessment and fishery evaluation
                    report for the 1993 Gulf of Alaska groundfish
                    fishery. North Pacific Fishery Management Council,
                    PO. Box 103136, Anchorage, AK 99510.


























                    Gulf of Alaska Groundfish Resources                                                                       43





                   14. FLATFISH

                  By Titomas K. WiNerbuer and Eric S. Brown



                                                                                                     _7
                                                                                                    -,a      VON%



                                         _4
                                                            -tv
                                                   7-

                                                                                                              F
                                                             R

                                                                                                         'N W;AT*
                                                       4





                                                                                              7
                                                                          41-
                                                                                                            4k@ 01@














                                                                                                                        Photo: AFSC
                     The flatfish species complex has been managed            flatfish assemblage into four categories: "shallow-
                 as a unit in the Gulf of Alqqka and includes the             watee, natfish,,,deep-wateel flatfish, arrowtooth
                 major species of flatfish inhabiting the region. The         flounder, and flathead sole. These classifications
                 major species, which compn    .ise
                 98% of the current biomass,                                            Flatf ish
                 include: arrowtooth flounder                                      Gulf of Alaska
                 (Atherestes stomias), flathead
                 sole (Hippoglossoides                       30 Catch (1.000 metric tons)            Biomass (1,000 metric tons) 3000
                 elassodon), rock sole
                 (Pleuronectes bilineatus), rex              25                                    Survey-Biomas             2500
                 sole (Errex zachirus), Dover sole
                 (Microstomus pacificus),
                 yellowfin sole (Pleuronectes                20                                                              2000
                 asper), and starry flounder                 15            .-Catch                                           1500
                 (Platichthys stellatus). Gulf of
                 Alaska flatfish are relatively                                                                              1000
                 slow-growing, long-lived species
                 with similar biological character-            5                                                             500
                 istics depending on the size of
                 the fish.                                                                                                   0
                    The NPFMC manages this                     0 64   67    70    73    76     79    82    85    Be    91
                 resource and has divided the                                              Year


                 44                                                          Gulf of Alaska Groundfish Resources








                  are necessary because of                                      rL&TFISH
                  the very different halibut
                                                                            Gulf of Alaska
                  bycatch rates that occur                                COMMERCIAL CATCH (t)
                  in the directed fisheries
                  tMeting on shallow- and      Year             Foreign          Joint            Domestic         Total
                  deep-water natnsh.                                           venture
                  Arrowtooth flounder,         ------------------------------------------------------------------
                  because of its present       1983             9,530            2,692            439              12,661
                  high abundance and low       1984             3,033            3,448            432              6,913
                                               19:5             170              2,447            461              3,078
                  commercial value, was        19 6             71               961              1,409            2,441
                  separated from the           1987             0                7,207            2,718            9,925
                  shallow- and deep-water      1988             0                1,781            8,494            10,275
                  groups and is m              1989             0                0                5,167            5,167
                                 anaged        1990             0                0                15,411           15,411
                  under a separate TAC         1991             0                0                20,068           20,068
                  limit. Flathead sole am      1992             0                0                28,000           28,000
                  likewise assigned a
                  separate limit because
                  they overlap the depth distributions of the shallow-    For further, information
                  and deep-water groups.
                     The Gulf of Almkn flatfish resource has been         Wilderbuer, T. K., and E. S. Brown. 1992. Flatfish.
                  underexPlOited since at least 1964. From 1978 to        In Stock assessment and fishery evaluation document
                  1981, the fishery caught about 15,000 t annually (all   for the 1993 Gulf of Alaska groundfish fishery, p.
                  species), which was nearly all the result of foreign    106-124. North Pacific Fishery Management
                  fishing in pursuit of non-flatfish species. By 1985,    Council, P.O. Box 103136, Anchorage, AK 995 10.
                  the catch decreased to less than one-half this amount
                  as the fishery changed from foreign to joint venture
                  operations. Catches increased to 10,300 t in 1988
                  and to 15,400 t in 1990 as joint venture fishing
                  ceased and a near-shore domestic fishery developed
                  at Kodiak Island. Catch levels increased to 20,000 t
                  and 28,000 t for 1991 and 1992, respectively, but
                  remained well below the TAC for both years.
                     Flatfish abundance information
                  is available Erom three triennial                                      FL&Triss
                  bottom trawl surveys conducted in                                 Gulf of Alaska
                  the Gulf of Alaska from 1984 to
                  1990. Generally, flatfish stocks              Average catch (1977-92)                       12,200 t
                  have experienced a minimum of                 Long-term potential yield (MSY)             169,000 t
                  exploitation historically and are             Acceptable biological catch (1992)       -   466,750 t
                  believed to be at abundant, stable            Exploitable biomass (1990 survey)        =2,750,000 t
                  levels. Size-composition informa-             Harvesting strategy                      wF0.1
                                                                Age/length at recruitment      = 3-4  yrs/ ?
                  tion from the surveys indicate a              Age/length at 50% maturity - 5 yrs/61 cm(females)
                  continuing presence of young fish             Maximum age                    = 15+ years
                  recruiting to the flatfish popula-
                  tions.                                        Abundance and trend                   High and Stable
                                                                Importance of recreational    fishery = Minor
                                                                Management                           = GOA Groundfish FMP
                                                                Assessment Method                    = Trawl surveys
                                                                Status of exploitation               = Under-exploited

                                                                M = 0.2-0.22    Fo., = 0.17-0.20, Fny = 0.3-0.6
                                                                F_fishuq  = 0.24-0.30     F107-1-92 =very low



                  Gulf of Alaska Groundfish Resources                                                                     45





                  15. SABLEFISH

                 By Sanda A. Lowe and Jeffrey T. Fqftoka


























                     The distribution of sablefish (Anoplopoma              4-6 years of age at sizes of 57-65 cm. Maximum age
                 fimbria) in North American waters ranges from the          is 55+ years, and maximum size is about 100 cm.
                 waters off northern Mexico through the Gulf of             Sablefish spawn at depths of 300-750 in generally
                 Alaska and along the Aleutian Island chain and             during the winter months. They are carnivores;
                 edge of the continental slope in the eastern Bering        adults feed primarily on fish and also nektonic and
                 Sea. Their range continues off the Siberia and             benthic invertebrates.
                 Kamchatka coasts of Russia to the northeast coast of          Sablefish of the Gulf of Alaska, eastern Bering
                 Japan. The resource is managed by discrete regions         Sea, and Aleutian Islands are considered one Large
                 to distribute exploitation throughout its wide             stock. They are managed by the NPFMC. This
                 geographical range. There are three management             resource has been harvested by U.S. and Canadian
                 areas in the northeast Pacific Ocean: the eastern          fishermen since the early 1900s, but catches were
                 Bering Sea, the Aleutian Islands region, and the           relatively low until the Japanese longline fleet began
                 Gulf of Alqqka                                             operations in the Eastern Bering Sea in 1958. The
                    Eggs, Larvae, and young-of-the-year juveniles are       fishery rapidly expanded and catches peaked at
                 pelagic, but older juveniles and adults are demersal.      26,000 t in 1962. The Japanese fleet then expanded
                 They have a wide depth distribution--young juve-           into the Aleutian Islands region and Gulf of Alaska
                 niles are found in surface and near-shore waters           Catches in the Aleut= Islands region have histori-
                 down to depths of 150 in, older juveniles are found        cally remained at low levels. In the Gulf of Alaska-
                 on or near the bottom in waters 100-200 m in depth,        catches reached 37,500 t in 1972 and averaged about
                 and adults are found in waters 150-1,200 m in              28,000 t during 1973-76.
                 depth. The bulk of the exploitable population                 Evidence of declining stock abundance led to
                 occupies depths of 400-1,000 m. Sablefish mature at        significant fishery restrictions Erom 1977 to 1985,


                 46                                                         Gulf of Alaska Groundfish Resources














                                                                        SABLZFISH
                                            Eastern Bering Sea, Aleutian Islands and Gulf of Alaska
                                                               COMMERCIAL CATCH (1,000 t)



                          Category           1983     1984     1985     1986 1987 1988        1989   1990    1991    1992
                          -----------------------------------------------------------------------------------
                          Eastern Bering Sea
                            Foreign           2.6     1.2      0.2      0.1   0.0
                            Joint venture     0.0     0.1      0.0      0.3   0.1    0.0      0.0
                            Domestic          0.1     1.0      2.1      3.1   4.1    3.2      1.2    2.3     1.2     0.6
                            Subtotal          2.7     2.3      2.3      3.5   4.2    3.2      1.2    2.3     1.2     0.6


                          Aleutian Islands
                            Foreign           0.6     0.7      0.1
                            Joint venture     0.1     0.3      0.1      0.1   0.1    0.0
                            Domestic                  0.0      1.3      2.9   3.8    3.4      3.2    2.2     2.1     1.4
                            Subtotal          0.7     1.0      1.5      3.0   3.9    3.4      3.2    2.2     2.1     1.4


                          Gulf of Alaska
                            Foreign           5.0     1.1      0.0      0.0
                            Joint venture     0.0     0.5      0.2      0.0   0.2    0.0
                            Domestic          3.8     8.6      12.2     21.6  26.1   29.9     29.8   25.7    19.6    20.8
                            Subtotal          8.8     10.2     12.4     21.6  26.3   29.9     29.8   25.7    19.6    20.8


                          Total               12.2    13.5     16.2     28.1  34.4   36.5     34.2   30.2    22.9    22.8


                    and total catches were reduced substantially. Total                       Sablef ish
                    catches increased steadily after 1983, reaching a                Gulf of  Alaska, Bering Sea,
                    peak of 36,500 t in 1988 with an ex-vessel value of            and Aleutian Islands Oombined
                    $783 million. Total sablefish commercial catch in
                    the eastern Bering SeatAleutian Islands and Gulf of
                    Alaska in 1992 was 22,700 t valued at $51 million         (Catch in 1,000 t)          (RPW index Points)
                    (ex-vessel value). Ihis species is of minor recre-      60                                              @500
                    ational importance.
                       Stock-reduction analysis revealed declining stock    50 --
                    sizes through 1978. Estimates of exploitable                                      RPW-Re1afivqB1ioma88- 400
                    biomass after 1979 were determined from survey
                    data by scaling indices of biomass from annual          40-
                    longline surveys to absolute biomass based on                    GOA Catch                               300
                    comparisons of longline and bottom trawl survey
                    catch rates. The surveys indicted that stock biomass    30-      B3A1 Catc
                    increased after 1980 and peaked in 1985 at nearly                                                        200
                    400,000 t. Lower exploitation rates and a strong
                    1977 year class, which recruited in 1982, led to this   20 -
                    improved stock condition. After 1986, stock size has
                    been relatively stable but has shown a slight decline.                                                   10
                                                                                                                             '0
                    Although stock size may be declining, there is no       10
                    evidence that it is being overfished. The decline is
                    attributed to the lack of significant recruitment in      04.11,11                                       0
                    recent years. Ile stock is at a high level and            56     61   r, C)  7.1    765  61     86   91
                    considered to be in good condition.                                            Year
                       In the past, a constant F,., fishing rate policy was
                    applied to sablefish. Recent simulation studies have


                    Gulf of Alaska. Groundfish Resources                                                                      47














                                                         RABI ISH
                                      Bering Sea, Gulf of Alaska, and  Aleutian Islands



                       Average catch (1977-92)                       = 20,900 t
                       Long-term potential yield (MSY)               = Unknown
                       Acceptable biological catch (1993)            = 25,000 t
                       @Exploitable biomass (1993)                   - 227,400 t
                       Harvesting strategy                             F33% * (B93 IB351)
                       Age/length at recruitment                     = 5 yrs/60 cm
                       Age/length at 50% maturity                    = 4-6 yrs/57-65 cm
                       Maximum age                                   = 55+ yrs
                       Abundance and trend                           = High and declining
                       Importance of recreational  fishery           = Minor
                       Management                                    = GOA and BSAI Groundfish FMPs
                       Assessment Method                             - Stock-reduction analysis
                                                                       and yield-per-recruit
                       Status of exploitation                        = Fully exploited

                       M = 0.10              F,., = 0. 13                           FwY    Unknown
                       F..,,"t'im = 0.16                                   0.09



             been conducted to examine harvest strategies that
             reduce the risk of overfishing. One of the strategies
             that reduces this risk, in comparison to a constant
             fishing rate strategy, is a variable rate that decreases
             proportionately as biomass decreases below a
             desirable reference level. Such a policy should
             reduce risk without appreciably reducing average
             catch levels. For 1993, sablefish were harvested
             under an F., strategy adjusted by the ratio of current
             biomass to B.. or (B,3iS3.,). The resource is
             considered fiffly utilized.

             For further information


             Fujioka, J.T. 1992. Sablefish. In Stock assessment
             and fishery evaluation report for the 1993 Gulf of
             Alaska groundfish fishery. North Pacific Fisheries
             Management Council, P.O. Box 103136, Anchorage,
             AK 995 10.


             Lowe, S A. 1992. Sablefish. In Stock assessment
             and fishery evaluation document for the 1993 Gulf of
             Alaska groundfish fishery. North Pacific Fishery
             Management Council, P.O. Box 103136, Anchor-
             age, AK 99510.

             Sigler, M.F., and J.T. Fujioka. 1992. Harvest
             policies for sablefish in the Gulf of Alaska. Proceed-
             ings of the Symposium on Management Strategies
             for Exploited Fish Populations. Lowell Wakefield
             Fisheries Symposium, OCL 21-24, 1992. Anchorage,
             Alaska.

             48                                                Gulf of Alaska Groundfish Resources






                                                                        16. SLOPE ROCKFISH

                                                                                     By David M. Clausen and Jonathan Heiefetz







                                                                   
                                                                                                           












                                                               











                                                                                                                           Photo: AFSC
                         The NPFMC presently classifies 20 Gulf of               the Gulf of Alaska.
                     Alaska rockfish species (genus Sebastes) into the              Of the eight major species of slope rockfish,
                     slope rockfish assemblage. Slope rockfish are               Pacific ocean perch has historically been the most
                     defined as those species of Sebastes that as adults         abundant and provided most of the commercial
                     inhabit offshore waters of the outer
                     continental shelf and continental                   Slope Rockfish (Gulf of Alaska)
                     slope, generally in depths greater than                   Primarily Pacific Ocean Perch
                     150-200 in. Trawl surveys in the Gulf
                     of Alaska indicate that eight species of     400 Catch (1,000 metric tons)       Biomass (1,000 metric tons)  1400
                     slope rockfish together comprise more        350
                     than 99% of the estimated total              300                                                              1200
                     biomass for the assemblage: Pacific                                                                           1000
                     ocean perch (Sebastes alutus),               250                                                               800
                     northern rockfish (S. polyspinis),           200                                                               600
                     rougheye rockfish (S. aleutianus),           150
                     sharpchin rockfish (S. zacentrus),           100                                                               400
                     redstripe rockfish (S. proriger),             50                                                               200
                     harlequin rockfish (S. variegatus),            0                                                                 0          
                     silvergray rockfish (S. brevespinis),            1960    1965    1970     1975     1980    1985     1990
                     and shortraker rockfish (S. borealis).                                      Year
                     The remaining 12 species appear to                   POP Biomass           Survey Biomass       Catch
                                                                                   





                     have a relatively sparse distribution in                                                

                     Gulf of Alaska Groundfish Resources                                                                               49
 









                   catch. Almost all research
                   on slope rockfish has                                             SLOPZ ROCKFISH
                   concentrated on Pacific                                 (Primarily Pacific ocean perch)
                                                                                     Gulf of Alaska
                   ocean perch; little biological                                COMMERCIAL CATCH (t)
                   or assessment information is
                   available for the other
                   species. Consequently, this        Year         Foreign             Joint           Domestic             Total
                                                                                     Venture
                   synopsis will deal mostly          ---------------------------------------------------------------
                   with Pacific ocean perch.          1983          5,415              1,975             15                 7,405
                      The Gulf of Alaska              1984          2,599              1,734             119                4,452
                   appears to be the center of        1985          8                  254               825                1,087
                                                      1986          0                  37                2,944              2,981
                   abundance for Pacific ocean        1987          0                  112               4,869              4,981
                   perch, although the species        1988          0                  8                 13,771             13,779
                   ranges south to the coastal        1989          0                  0                 19,002             19,002
                   waters of southern Califor-        1990          0                  0                 21,114             21,114
                                                      1991          0                  0                 13,994             13,994
                   nia, north to the Bering Sea       1992          0                  0                 17,300             17,300
                   and west to the Pacific coast
                   of Russi& The species is
                   slow-growing and long-
                   lived; a maximum age of 78 years has been reported          northern rockfish, which is found in shallower water
                   from the Gulf of Alaska Because of this slow                on the outer continental shelf.
                   grow th and longevity, the estimated rate of instanta-          The Pacific ocean perch stock was severely
                   neous natural mortality (0.05) is quite low compared        depressed when the Japanese fishery ended in 1984.
                   with most other groundfish species. This species            The stock apparently never rebounded from the
                   begins to recruit to the fishery at about age 5 and is      overfishing that occurred in the 1960s. More recent
                   fully recruited by age 16, corresponding to fork            assessments of Pacific ocean perch, based primarily
                   lengths of 27 cm and 40 cm, respectively. The               on trawl surveys in 1984, 1987, and 1990, showed
                   maximum length recorded is 51 cm. The sparse                that the stock was still low. There was, however,
                   information on other slope rockfish species indicates       some evidence of successful recruitment, especially
                   that they are also slow-growing and long-lived.             from relatively strong 1976 and 1980 year classes.
                      Commercial fishing for Pacific ocean perch in the        The current stock condition is uncertain, although it
                   Gulf of Alaska began in the early 1960s by Soviet           is still thought to be very depressed compared to its
                   and Japanese trawlers. Catches peaked in 1965 at            former (pre- 1960) abundance. Recently, a stock
                   350,000 L Ile stock could not sustain this heavy            synthesis model has been applied to Pacific ocean
                   level of exploitation, and catches declined precipi-        perch that incorporates data from a variety of
                   tously in the late 1960s. This decline continued in         sources, including past age compositions, biomass
                   the 1970s and early 1980s. When the foreign trawl           estimates from the three trawl surveys, and CPUE
                   fishery was terminated in 1984, the catch of Pacific        data from the commercial fishery. Based on this
                   ocean perch totaled only 4,500 L                            model, the current best estimate of exploitable
                      A significant domestic fishery for slope rockfish        biomass for Pacific ocean perch is 153,600 L
                   developed in 1985, and catches increased annually              In 199 1, the NPFMC divided the slope assem-
                   until 1990 when the total was 21,114 L In 1991 and          blage into three management subgroups: Pacific
                   1992, catches diminished somewhat as a result of            ocean perch, shortraker-rougheye, and "other slope
                   more restrictive management policies. The gross             rockfish." The reason for this division was to
                   wholesale value of the 1992 trawl catch is estimated        prevent possible selective overharvest of the more
                   at $22 million. Over the years of this domestic             highly valued species in the assemblage. In 1993,
                   fishery, Pacific ocean perch has apparently been the        the NPFMC further divided "other slope rockfish" by
                   major species caught. Recent fisheries, however,            separating out northern rockfish as its own manage-
                   also target on shortraker and rougheye rockfish, two        ment subgroup. Separate ABCs and TACs are now
                   larger sized species that inhabit deeper waters             assigned to each of the four subgroups. Pacific
                   (greater than 300 m) of the continental slope, and on       ocean perch is currently managed under an F3,,


                   50                                                          Gulf of Alaska Groundfish Resources















                                                                 PACMC OCEAN PERCH
                                                          (Dominant Slope Rockfish Species)
                                                                    Gulf of Alaska



                             Average catch (1977-92)                     = 11,280 t (includes other species of
                                                                           slope rockfish)
                             Long-term potential yield (MSY)             = Unknown
                             Acceptable biological catch
                                (1993)                                   = 5,560 t (21,580 t for assemblage)
                             Exploitable biomass (1993)                  = 153,600 t (457.036 t for assemblage)
                             Fishing strategy                            = F - F3,,; F = M for other species
                             Age/length at recruitment                   = 5-16 years/27-40 cm
                             Age/Length at 50t maturity                  = Males: 5.0-6.2 years/27.5-30.5 cm
                                                                           Females: 5.4-10.0 years/28.5-36.3 cm
                             Maximum age                                 = 78 years
                             Abundance and trend                         = Low and uncertain.
                             Importance of Recreational
                               Fishery                                   = Minor
                             Management                                  = GOA Groundfish FMP
                             Assessment   level                          = Yield-per-recruit/stock synthesis
                             Status of exploitation                      = Fully utilized

                             M - 0.05                  F0.1 = 0.08                        FwY    Unknown
                             F_rflehim =   0.08                 F1977-92 awray. 0,07




                    harvesting strategy, whereas shortraker-rougheye,
                    northern rockfish, and "other slope rockfish" are
                    managed using an F = M strategy.

                    For further information


                    Heifetz, J., and D. M. Clausen. 1992. Slope
                    rockfish. In Stock assessment and fishery evaluation
                    report for the 1993 Gulf of Alaska groundfish
                    fishery. North Pacific Fishery Management Council,
                    P.O. Box 103136, Anchorage, AK 99510.

                    Heifetz, J., and J. N. Ianelli. 1992. Stock assess-
                    ment of Pacific ocean perch in the Gulf of Alaska
                    based on the stock synthesis model. In Stock
                    assessment and fishery evaluation report for the
                    1993 Gulf of Alaska groundfish fishery, Appendix
                    IV. North Pacific Fishery Management Council,
                    P.O. Box 103136, Anchorage, AK 99510.










                    Gulf of Alaska Groundfish Resources                                                                       51





               17. PELAGIC SHELF ROCKFISH

               By David M. Clausen and Jonathan Heifetz



                  Ile pelagic shelf                                 DUSKY ROCKFISH
               rockfish management                    (Dominant Pelagic Shelf Rockfish Species)
               assemblage in the                                    Gulf of Alaska
               Gulf of Alaska
               includes five species   Average catch (1988-92)                   = 2,050 t (includes other
               of Sebastes. These                                                  species of pelagic shelf
               fish typically inhabit                                              rockfish)
               waters of the conti-    Long-term potential yield (MSY)           = Unknown
               nental shelf of the     Acceptable biological catch (1993)        = 6,740 t
               Gulf of Alaska and      Exploitable biomass (1993)                = 74,900 t
                                       Harvesting strategy                       = F = M
               exhibit a midwater      Age/length at recruitment                 = Unknown/unknown
               schooling behavior.     Age/length at 50% maturity                = Unknown/unknown
               At times, however,      Maximum age                               = 49 years
               some of the fish am     Abundance and trend                       = Both unknown
                                       Importance of recreational   fishery      = Minor
               found near the          Management                                = GOA Groundfish FMP
               bottom where they       Assessment  Method                        = Trawl surveys
               Can be Captured Using   Status of exploitation                    = Under-exploited
               bottom trawls.          M = 0.09                F0.1 = Unknown          Fw, = Unknown
               Dusky rockfish          F@rflbinq = Unknown      F2979-92      Unknown
               (Sebastes ciliatus) is
               the most abundant
               species in the
               assemblage. Trawl surveys have shown this species   and 1992, however, a jig fishery for black rockfish
               to comprise 92-99% of the total biomass for the     (Sebastes melanops) developed in the central Gulf of
               group. Most of this synopsis, therefore, will deal  Alaska, and this fishery caught 500 t each year.
               with dusky rockfish.                                   The only stock-assessment information for
                 There is relatively little biological information on pelagic shelf rockfish comes from three bottom trawl
               dusky rockfish. Ile species ranges from the waters  surveys in the Gulf of Alaska. Estimated exploitable
               off northern British Columbia to the Bering Sea and biomass for dusky rockfish in these surveys showed a
               is apparently most abundant in the Gulf of Alaska.  wide variation, from 37,313 t in 1994, increasing to
               Maximum reported age is 49 years, but there are no  163,188 t in 1987, and falling to 24,141 t in 1990.
               data on age or size of recruitment. A natural       These large fluctuations do not appear to be reason-
               mortality rate (M) has been recently estimated at   able when one considers the low natural mortality
               0.09, which indicates that dusky rockfish is rela-  rate for dusky rockfish and the relatively small
               tively fast-growing compared to most other rockfish commercial catches. One hypothesis is that some
               species in Alaska. Dusky rockfish can attain a      portion of the population may have moved off bottom
               maximum length of 53 cm.                            in 1984 and 1990 and hence, was not captured in the
                 Catch statistics for pelagic shelf rockfish in the survey. Thus, present stock condition of pelagic
               Gulf of Alqqka are only available beginning in 1988 shelf rockfish is uncertain, although dusky rockfish
               when this management group was created. In          are thought to be more abundant now am they were
               general, catches have increased during this time    in the 1960s and 1970s.
               period. Nevertheless, they have remained much less     Pelagic shelf rockfish are presently managed
               than the assigned TAC, which indicates the assem-   using an F = M strategy, in which ABC is deter-
               blage has been underutilized. Most of the catch has mined by applying the natural mortality rate for
               been dusky rockfish taken by bottom trawls. In 1991 dusky rockfish (0.09) to the exploitable biomass of


               52                                                  Gulf of Alaska Groundfish Resources







                  the assemblage. Due to the uncertainty of the trawl                DUSKY ROCKFISH
                  survey results, the average of the exploitable       (Dominant Pelagic Shelf Rockfish Species)
                  biomass estimates Erom the three surveys (74,889 t)                Gulf of Alaska
                  is used for these Computations.                                 COMMERCIAL CATCH (t)

                  For further information                                   Western    Central    Eastern      Total

                                                                     ---------------------------------------------
                  Clausen, D. M., and J. Heifetz. 1992. Pelagic      1988      400        518        168      1,086
                  shelf rockfish. ju Stock assessment and fishery    1989      113        888        737      1,738
                  evaluation report for the 1993 Gulf of Alaska      1990      165        955        527      1,647
                                                                               215        1191       937      2,342
                  groundfish fishery. North Pacific Fishery Manage-  1991        73       2387       980      3,440
                                                                     1992
                  ment Council, P.O. Box 103136, Anchorage, AK
                  99510.














































                  Gulf of Alaska Groundfish Resources                                                                53





              18.DEMERSAL SHELF ROCKFISH

              By Victoria M. O'Conneft and Jeffrey T. Fqfloka




                The demersal shelf rockfish assemblage includes Waked in 1987 at 726 L Catches declined in 1988
              eight species of rockfish that are found most com- to 505 t and further to 3 10 t in 1989. Much of the
              monly near shore at depths less than 200 in off  decline in harvest can be attributed to closures of the
              Southeast Alaska The two most important species  directed fishery for conservation. The TAC was
              in the assemblage, yelloweye rockfish (Sebastes  reduced Erom 660 t in 1988 to 420 t in 1989 and
              ruberrimus) and the quillback rockfish (S. maliger) then increased to 470 t in 1990 to allow for an
              are distributed from the waters off California to increase in bycatch. In 1991, the ABC was con-
              Prince NNilliam Sound. The demersal shelf rockfish strained to 445 t, the mean catch since 1982 to 1989,
              are managed by the NPFMC as a distinct assemblage as required by the NPFMC overfishing definition.
              only off southeast Alaska where they are targeted by In 1992 the Southeast Outside district@ defined
              a small shore-based fishery. Management in the   for demersal shelf rockfish (DSR) management, was
              EEZ is done jointly by the NPFMC with the        expanded 20 west, to long. 14(r W. Since 1992
              ADF&G.                                           biomass has been derived from a combination of
                Species in the demersal shelf rockfish assemblage density of yelloweye rockfishAan2estimates from
              we ovoviviparous, with the majority of fish extrud- submersible line transects, areal estimates of
              ing larvae in late winter and spring. Yelloweye  available'!rocky" habitat, and mean weight data
              rockfish extrude larvae over an extended time    from the commercial fishery. In 1993, the ABC and
              period, with the peak period occurring in April and TAC (800 t) were set by multiplying the lower end of
              May. Like other rockfish, the demersal shelf     the 90% confidence interval for biomass (40,049 t)
              rockfish are considered to be slow-growing and long- by the natural mortality rate (0.02).
              lived with a low natural mortality rate. The ages of Yelloweye rockfish, the primary target species,
              yelloweye rockfish caught by the fishery range from accounted for over 85% of the landed weight in the
              13 to 114 years, with first modes occurring around 1992 DSR longline fishery. Dernersal shelf rockfish
              35 years of age *in                                                                           I
              lightly exploited                                SUCTS ROCKFISH CONPLEX
              areas and around                                 Gulf of Alaska
              18-20 years in
              exploited arms.    Average catch (1982-92)                = 450 t
                Dernersal Shelf  Long-term potential yield (MSY)        = Unknown
              rockfish have been Acceptable biological catch (1993)     = 800 t
                                 Exploitable biomass (1993)             = 40,000 t
              landed incidental  Harvesting strategy                    = Accommodate  directed and
              to other fisheries                                          bycatch fishery needs
              in Southeast       Age/length at recruitment              = 20 years/51-54 cm
              Alaska since the   Age/length at 50% maturity             = 20-25 years/47-49 cm
                                 Maximum age                            = 114+ years
              turn of the century Abundance and trend                   = Unknown and declining
              In 1979, a small   Importance of recreational fishery     = Minor
              shore-based        Management                             = GOA Groundfish FMP
              rockfish fishery                                                        and State of Alaska
                                 Assessment Method                      = Yield-per-recruit with line
              began, targeting                                            transect density
              primarily on this  Status of exploitation                 = Local depletions
              nearshore bottom-
              dwelling complex.  M = 0-02               F.., = 0. 03          FwY = Unknown
              The directed       F@rflshi'q = 0.04      F197"Sawmv' = Unknown
              harvest of demer-  (Values for age, length, M and F are for .9rJaa.&t= riihPrrJmiv%)
              sal shelf rockfish



              54                                               Gulf of Alaska Groundfish Resources










                       are also taken as bycatch
                       in the longline fishery for                                DFIelLSAL SHUY ROCKFISH
                       halibut and in trawl                                             Gulf of Alaska
                       fisheries for "slope                                         COMMERCIAL CATCH (t)
                       rockfish." While the
                       directed fishery harvest         Category        1984 1985 1986 1987 1988 1989 1990 1991 1992
                       has been declining since         ----------------------------------------------------------------
                                                        Directed         543      388   449     726     505    310     199    386      352
                       1987, the reported bycatch       Incidental         20     100     41     47      53    103     128    119      215
                       has incremed dramati-            Total            563      488   491     773     558    413     327    505      567
                       cally. The recreational
                       fishery is of minor
                       significance at this time; most fish are taken inciden-
                       tally and there is only occasional targeting on
                       yelloweye and quillback rockfish.
                          In past years, shifts in effort to grounds farther
                       from the port of landing have been noted in all five
                       Gulf of Alaska management areas. Considering that
                       most Southeast Alaskan processors limit trip time to
                       4 days and the additional cost associated with fishing
                       farther from port, the progressive expansion to more
                       distant fishing grounds is considered to be a strong
                       indication that abundance has declined near the
                       major ports.

                       For further information


                       O'Connell, V. M. 1987. Reproductive seasons for
                       some Sebastes species in Southeastern Alaska.
                       Alaska Dep. Fish and Game Info. Leaflet No. 263.
                       Juneau, AK.

                       O'Connell, V. M., and F. C. Funk. 1987. Age and
                       growth of yelloweye rockfish (Sebastes ruberrimus)
                       landed in Southeastern Alaska. Ln B. R. Melteff
                       (ed.), Proceedings of the International Rockfish
                       Symposium. p. 171-185. Alaska Sea Grant Report
                       No. 87-2.


                       O'Connell, V. M., D.W. Carlile, and B. E. Bracken.
                       1992. Demersal shelf rockfish. Ln Stock assessment
                       and fishery evaluation report for the 1993 Gulf of
                       Alaska groundfish fishery. North Pacific Fishery
                       Management Council, P.O. Box 103136, Anchorage,
                       AK 99510.


                       O'Connell, V.M., and D.W. Carlile. 1993. Habitat
                       specific density of adult yelloweye rockfish in the
                       eastern Gulf of Alaska. Fish. Bull., U.S. 91(2):
                       304-309.





                       Gulf of Alaska Groundfish Resources                                                                                55





                  19. THORNYHEADS

                 By Loh-Lee Low















                                                            W
                                                              Alrw@

                                                                                                  X












                                                                                                                     PhotD: AFSC
                    71bornyheads of the northeastern Pacific Ocean          expanded. The catch peaked in 1989 at 3,079 L
                are comprised of two species, the shortspine                Catches since 1991 have been close to the estab-
                thornyhead (Sebastolobus alascanus) and the                 lished quota. In 1992, the ex-vessel value of the
                longspine thornyhead (S. altivelis). The longspine          catch was $1.7 million.
                thornyhead is rare in the Gulf of Alaska. Shortspine           Based on trawl survey data, abundance of
                thornyheads occur demersally along the continental
                slope from 100 to 1,500 rn in depth from Baja                               SHORTSPINE THORNYEZADS
                California to the Bering Sea. In the Gulf of Alaska,                              Gulf of Alaska
                greatest concentrations are found at 300 - 700 m.                            COMMERCIAL CATCH (t)
                    Thornyheads are slow-growing and long-lived
                with maximum age in excess of 50 years and                       Year Foreign Joint Domestic             Total
                maximum size greater than 50 cm and 2 kg.                                         Venture
                lbornyheads are caught by trawl and longline gear                --------------------------------------
                with the bulk of the fishery occurring in late winter            1983         716       13          0        729
                                                                                 1984         165       19         24        208
                or early spring through the summer.                              1985             4     9          69        82
                   Thornyheads am managed under the Gulf of                      1986             0     1         713        714
                Alaska groundfish FW. Caches were mainly made                    1987             0     20    1,943      1,963
                by foreign fisheries until the early 1980s and were              1988             0     8     2,787      2,787
                                                                                 1989             0     0     3,079      3,079
                less than 1,400 L The catch decreased markedly in                1990             0     0     1,646      1,646
                1984 and 1985 because of restricted foreign fishing              1991             0     0     1,217      1,217
                in the Gulf. In 1985, the U.S. catch surpassed the               1992             0     0     1,653      1,653
                foreign catch for the first time as U.S. fisheries


                56                                                         Gulf of Alaska         Groundfish Resources







                    thornyheads in the Gulf of Alaska                           SHORTSPIM THORWEEADS
                    has declined sharply from 123,000 t                             Gulf of Alaska
                    in 1984 to 99,000 t in 1987, and to
                    26,000 t in 1990. Since abundance
                    of thornyheads was first measured      Average catch (1981-92)                    =   1,350 t
                    in 1984, landings have never           Long-term potential yield (MSY)            = Unknown
                    exceeded 6.5% of biomass, while        Acceptable biological catch (1993)         -   1,180 t
                                                           Exploitable biomass (1993)                 =  26,200 t
                    from 1984 to 1988, landings did        Harvesting strategy                        =  F35%
                    not exceed 4%.                         Age/length at recruitment                  =  16 yrs/25 cm
                       The MSY for thornyheads             Maximum age                                =  62+ yrs
                                                           Abundance and trend                        =  Low and declining
                    cannot be estimated. Acceptable        Importance of recreational fishery         =  Minor
                    biological catches, however, were      Management                         = GOA Groundfish FMP
                    estimated from survey biomass data     Assessment   Method                = Yield-per-recruit
                    at 1,798 t for 1992 and 1,180 t for    Status of exploitation             = Fully exploited
                    1993.                                  M = 0.05 F0.1 = 0.07      F,,, = 0.05    F,,,,   0.045
                                                           [email protected]   0.055      F.@_q. = 0. 03

                    For further information


                    Dawson, P. K. 1992. Thornyheads.
                    In Stock assessment and fishery
                    evaluation report for the 1993 Gulf
                    of Alaska groundfish fishery.
                    North Pacific Fishery Management
                    Council, P.O. Box 103136, Anchor-
                    age, AK 99510.





























                    Gulf of Alaska Groundfish Resources                                                                     57





                 20. PACIFIC HALIBUT

                 By Pwrkk J. SuMan





                    The Pacific halibut,
                 Hippoglossus stenolepis, is the
                 largest member of the flounder
                 family Pleuronectidae with males
                 weighing up to 54 kg and females
                 weighing up to 230 kg. Commer-
                 cially caught Pacific halibut gener-
                 ally range in age from 8 to 17 years,
                                                                     LIM
                 although the oldest recorded age for
                 a Pacific halibut is 42 years. Males
                 become sexually mature between the
                 ages of 7 and 13 years, while females
                 mature at 9 to 15 years. During the
                 spring and summer feeding periods,
                 Pacific halibut are found on the
                 continental shelf along the Pacific
                 coast of North America, with the
                 bulk of the population residing in the
                 Gulf of Alaska. In the winter, adult
                                                                                  A
                 Pacific halibut migrate to spawning
                 grounds along the continental slope.
                   The Pacific halibut population
                 has supported a directed longline
                 commercial fishery since the late
                 1800s. Longliners use gear consist-
                 ing of groundline, gangions, and
                 hooks. A skate of gear is commonly
                 made up of 1,800 ft of groundline,                                                     :9  -4      4*
                 with gangions attached every 18 ft
                 The J-shaped hook traditionally
                 attached to each gangion has
                 gradually been replaced by a more
                 efficient circle hook. Most of the
                 fleet now uses snaps to attach the
                 gangion to the groundline, although
                 some fishermen continue to use
                 'Tixed" gear with the gangions                                                                        PhotD: WHO
                 permanently attached.                                     and develop the Pacific halibut fishery. The fishery
                   In 1923, a Convention between Canada and the            Js regulated by controlling catch through time and
                 United States established the International Pacific       area closures in U.S. waters and by individual quota
                 Halibut Commission, originally called the Intema-         management in Canada. In the United States, over
                 tional Fisheries Commission, to manage the Pacific        6,300 vessels were commercially licensed to operate
                 halibut resource. The Commission directs research         in 1992, while in Canada, where an Individual
                 and establishes management regulations to preserve        Vessel Quota System was implemented in 199 1,



                 58                                                        Gulf of Alaska Groundfish Resources










                          435 vessels were eligible to fish.
                             In 1992, nearly 36,000 t of Pacific halibut                                      P  Iacific Halibut
                          were landed by the commercial longline
                          fishery: 3 1,000 t in the United States and                           Alaska, Canada, and Pacific Coast
                          5,000 t in Canada, with a total ex-vessel
                          value of $66 million (U.S.). The 1992                               50- Catch (1,000 t)                    Biomass (1,000 0     250
                          harvest reflects a 3% increase in yield from
                          the 34,000 t of Pacific halibut commercially
                          landed in 199 1. Other removals of Pacific                          40-                                                        -200
                          halibut in 1992 include 4,300 t landed by
                          recreational fisheries, 1,500 t wastage due to                      30---                                                      - 150
                          gear loss and discard, and 9,500 t lost to
                          mortality by fisheries not specifically directed
                          at halibut.                                                         20-----                                                    - 100
                              The stock is assessed on an annual basis
                          using an area by area catch-at-age analysis.
                          The exploitable biomass was estimated to                            10-                                                        -50
                          peak at 217,000 t in 1987 and 1988 after a
                          period of stock rebuilding. The population                           0-                                                         0
                          has declined since that time at an average                             1974     1977    1980     1983    1986     1989     1992
                          rate of 7% per year. Strong 1977 and 1979                                                        Year
                          year classes contributed to this build-up of the
                          stock with weaker year classes subsequently                               M Catch (U.S.)                Catch (Canada)
                          contributing to the decline.                                                   Blomass
                              Research on optimal exploitation strate-
                          gies indicate that a constant 30% harvest rate
                          on the exploitable portion of the stock will
                          maximize the yield of Pacific halibut with
                          minimum risk to the popula-
                          tion. After accounting for
                          other removals this translates,                                                 PACIFIC HALIBUT
                          as a management objective, to a                                       Alaska and the Pacific Coast
                          commercial harvest rate of 0.20
                          on the fully exploitable stock
                          with the instantaneous fishing              Average catch (1977-92)                                 =  28,520 t
                          mortality rate ranging from                 Long-term potential yield (MSY)                         =  30,000-36,000 t
                                                                      Exploitable biomass (1992)                              =  161,000 t
                          0.05 to 0.25 for fish larger than           Abundance and trend                                     =  High and declining
                          the 82 cm size limiL Directed               Status of exploitation                                  =  Fully exploited
                          commercial fishing mortality                Importance of recreational              fishery         =  Major
                          rates on legal-sized Pacific                Management                                              =  International Pacific
                                                                                                                                 Halibut Commission
                          halibut were relatively constant            Age/length      at 50% maturity                         =  Male 8 yrs/72 cm
                          during the period of stock                                                                             Female 12 yrs/122 cm
                          increase averaging 0.20 during              Assessment      Method                                  =  Age structured
                          the years 1974 through 1985.                M = 0.20              F0.1     0.16         Fmsy      0.22          F1112 =  0.33
                          More recently the fishing
                          mortality rate has increased to







                          Gulf of Alaska Groundfish Resources                                                                                                    59







                an average of 0.32. The change in the average rate                  PACIrIC HALIBUT
                results Erom a combination of factors including stock        Alaska and the Pacific Coast
                decline and an increase in fleet participation in the               CATCH (1,000 t)
                fishery.
                                                                   YEAR       RECREATIONAL     COMMERCIAL       TOTAL
                For further information                            --------------------------  U.S.--Canada --------
                                                                                               ---- ------

                                                                   1983            1.0         19.9     3.3     24.2
                International Pacific Halibut Commission. 1987.    1984            1.1         21.7     5.5     28.3
                The Pacific halibut: Biology, fishery, and manage- 1985            1.6         27.6     6.3     35.5
                                                                   1986            2.0         35.3     6.8     44.1
                ment. 1PHC Tech. Rep. 22., 59 p. Int. Pacific      1987            2.2         34.6     7.4     44.2
                Halibut Comm., P.O. Box 95W9, Seattle, WA          1988            3.1         37.2     7.8     48.1
                98145-2W9.                                         1989            3.3         34.2     6.3     43.8
                                                                   1990            3.6         32.1     5.2     40.9
                                                                   1991            4.2         30.1     4.3     38.6
                International Pacific Halibut Commission. 1990.    1992            4.0         31.1     4.6     39.7
                Annual Report, 1990.40 p. Int. Pacific Halibut
                Comm., P.O. Box 95009, Seattle, WA 98145-2009.








































                60                                                  Gulf of Alaska Groundfish Resources





                                                               21. PACIFIC HERRING

                                                                                                By Mar G. Wespestad











                                                f   71 7"











                                                                                                          TIN"



                                                                   @_X






                                       V
                                             MEW

                                                                                                           Photo: AFSC
                      The Pacific herring (Clupea pallasi) occurs      occur during the herring spawning period, which
                   throughout the Gulf of Alaska, Bering and Chukchi   runs from late March in Southeast Alaska to late
                   Seas and have been reported to occur in the Arctic  June in Norton Sound. A small amount of herring is
                   Ocean east to the Mackenzie River Delta. Major      also harvested for sale or use as bait. The principal
                   concentrations of herring in the Gulf of Alaska occur bait fisheries occur in winter in southeastern Alaska
                   in the waters off Southeast Alaska, Prince William  and in summer in
                   Sound, and Kodiak Island-Cook Met. In the Bering    the Bering Sea          PACIFIC EWMNG
                   Sea, major centers of abundance are northern Bristol around Unalaska             Alaska
                   Bay and Norton Sound. In the Chukchi Sea and the    Island.              COMMERCIAL CATCH (t),
                   Arctic Ocean, abundance is low and commercial          Current
                   concentrations of herring have been located only in herring fisheries    YEAR Gulf of Bering
                   Kotzebue Sound.                                     occur within the             Alaska   Sea
                      Herring have been exploited in Alaska since the  State waters of      ---------------------
                   late 1800s. Early fisheries produced salted and dried Alaska and am      1963    13,610  34,662
                                                                                            1984    18,431  28,103
                   herring. In the 1920s, herring began to be utilized managed by the       1985    18,085  36,625
                   in reduction fisheries in which oil and fish meal   ADF&G. Herring       1986    20,725  29,324
                   were the principal products. The reduction fisheries were harvested in   1987    27,223  22,718
                   continued into the mid-1960s when high production   the eastern Bering   1988    29,869  22,016
                                                                                            1989     9,557  25,778
                   of lower cost Peruvian anchovy oil and meal made it Sea EEZ by           1990    21,389  19,140
                   unprofitable to operate reduction plants in Alaska. foreign fisheries    1991    24,443  16,200
                   In the early 1970s, herring fisheries shifted to    from 1959 to         1992    34,a48  31,739
                   harvesting roe-bearing herring. These fisheries     1980. In 1980,

                   Pelagic Resources                                                                                6 1















                                                          PACIFIC HERRING
                                              Gulf of Alaska and Eastern Bering Sea



                                                               Gulf of Alaska          Bering Sea
                      --------------------------------------------------------------------------------
                      Average catch (1977-92)                  17,848 t                23,863 t
                      Long-term potential yield                Unknown                 Unknown
                      Acceptable biological catch
                         (1992)                                34,348 t                31,739 t
                      Fishing strategy                         0.1 to 0.2 of           0.1 to 0.2 of
                                                               exploitable biomass     exploitable biomass
                      Age of recruitment                       3 years                 4 years
                      Length/weigbt at recruitment             170 mm/85 g             220 mm/143 g
                      Maximum age                              12 years                18 years
                      Abundance and trend                      Moderately-high         Low and
                                                                and increasing           declining
                      Recreational importance                  None                    None
                      Subsistence use                          Minor                   Major
                      Management                               Alaska Department
                                                                of Fish and Game
                      Assessment method                        Survey,                 Aerial survey,
                                                                age-structured           age structured
                      Status of exploitation                   Fully utilized          Fully utilized
                      Natural Mortality (M)                    0.45                    0.27




              allocations ended and herring became a prohibited    In 1992, 56,426 t of herring were harvested in
              species in U.S. waters.                              Alaska with a total ex-vessel value of $30 million.
                 Pacific herring exhibit a south-to-north cline in 7le majority of the harvest was roe herring, and the
              life history features. Near the southern end of their remainder was food and bait herring and roe on
              range, herring have a shorter age span, an earlier   kelp.
              age of maturity, a higher rate of natural mortality,
              and a smaller size at age. In Southeast Alaska,      Gulf of Alaska -- Herring harvests in the Gulf of
              herring mature at age 3 and have a maximum life      Alaska have averaged 19,800 t since 1977. South-
              span of about 10 years. Herring in the Togiak        east Alaska and Prince William Sound roe-herring
              region, however, mature at age 4 and a maximum       fisheries have accounted for the bulk of the Gulf of
              age of 18 years has been observed. Natural mortality Alaska catch. Catches in all Gulf of Alaska herring
              also appears to increase with age in Pacific herring. stocks rose in 1992 due to the recruitment of a Gulf-
                 Mean length at age is greatest in herring spawn-  wide strong 1988 year class.
              ing in the southeastern Bering Sea (Togiak) and
              decreases in herring found to the north (Norton      Bering Sea -- Herring fisheries in the Bering Sea
              Sound, Kotzebue). Off Southeast Alaska, the          occur in spawning areas along the western Alaska
              maximum size of herring is 248 mm and 210 g.  In     coasL Ni*r harvests occur in the Togiak area of
              Prince William Sound (in the central Gulf of         Bristol Bay and in Norton Sound, and smaller
              Alaska), herring grow to a maximum of 252 mm and     amounts are harvested in other areas. Inshore
              220 g. In the Bering Sea, maximum length and         herring fisheries developed in the Late 1970s as the
              weight vary from 323 mm and 466 g in Togiak to       foreign trawl and gill-net fisheries were phased out.
              308 min and 359. g in Norton Sound.                  Catches rose from 14,000 t in 1977 to a peak catch
                 The ADF&G regulates and monitors 20 separate      of nearly 37,000 t in 1985. Since 1985, the catch
              herring fisheries. The information from these        has been declining in the southeastern Bering Sea
              fisheries is divided into Gulf of Alaska and Bering  but has been increasing in the northeastern Bering
              Sea components to provide a general overview of the  Sea. As in the Gulf of Alaska, the Bering Sea catch
              catch and status of Pacific herring in Alaska by area. improved in 1992 with the recruitment of a strong


              62                                                                         Pelagic Resources









                      1988 year class. Norton Sound did
                      not have a fishery in 1992 due to ice                                    Herring
                      coverage of the spawning grounds.                        Gulf of Alaska and Bering Sea
                        A portion of the Bering Sea
                      harvest is taken as bycatch 'in the         60- catch (1,ooo metric tons)
                      groundfish fishery. Bycatch cannot                     Gulf of AlaSka
                      be retained but is counted in the
                                                                  50-  M-E@-,ring Sea
                      catch. Bycatch has averaged 2,000-
                      4,000 L                                     40-

                      Stock Trends --Herring harvest              30---- -
                      levels are based on aerial surveys,
                      spawn deposition surveys,                   20-
                      hydroacoustic surveys, and age
                      composition of commercial and test-         10-
                      fishing catches. Harvest levels are
                      generally set at 20% of the esti-            0
                      mated biomass, but can range down                77      79      81      63      85       87      89       1
                      to 10%. Exploitation thresholds                                               Year
                      have been established for most
                      stocks below which fishing is not permitted.
                         In the Gulf of Alaska, the overall abundance of
                      herring is at moderate to high levels, although some
                      stocks are depressed or declining. A strong 1984
                      year class is reported to be present in most fisheries.
                      A very strong 1988 year class is reported in South-
                      east Alaska Prince William Sound, and other areas
                      are expected to further increase the abundance of
                      herring in the Gulf of Alaska in 1993.
                         In the Bering Sea, the abundance of herring
                      declined through the 1980s as the very strong 1977-
                      78 year classes which sustained the fisheries aged
                      and declined in abundance. In 1992, a strong 1988
                      year class also became evident in eastern Bering Sea
                      stocks. This year class is expected to increasl: stock
                      biomass in the near future.


                      For further information


                      Funk, F. 1993. Preliminary forecasts of catch and
                      stock abundance for 1993 Alaska herring fisheries.
                      Regional Information Rep. No. 5J93-06,109 p.
                      Alaska Dep. Fish and Game, 333 Raspberry Road,
                      Anchorage, AK 99518.









                      Pelagic Resources                                                                                                 63





                                                           SHELLFISH RESOURCES

                                                                                                               By Jerry E. Reeves





                           JIL 0'












                               -4







                                                  _ftno                                                                         A

                                    OPP'.










                        V4






                                                                                                                            PhotD: AFSC
                        The major shellfish resources off Alaska are king      against the landing of females. In addition,
                    crab, Tanner crab, shrimp, and sea snails.                 quotas, time-area closures, fishing seasons, gear
                       The king and Tanner crab fisheries of the Bering        restrictions and at-sea observers are used routinely
                    Sea and Aleutian Islands region are managed                for management of the stocks. Commercial crab
                    cooperatively by the State of Alaska and the Fedezal       fishing gear is restricted to pots (traps), and
                    govemmenL A FMP developed by the NPFMC                     recreational and subsistence fisheries are insignifi-
                    provides for delegation of management authority to         cant compared to commercial landings except in
                    the Alaska Board of Fisheries, with the NPFMC              areas which no longer have commercial harvests
                    having oversight authority. Thus the ADF&G and             of former commercial species. Snail fisheries are
                    NMFS cooperate in assessment and management of             basically undeveloped, although some limited
                    the fisheries. Alaska shrimp and crabs in the Gulf of      exploratory operations have occurred in recent
                    Alaska are managed by the Alaska Board of Fisher-          years.
                    ies. Management of Bering Sea snails is provided              This section focuses primarily on the crab
                    for by a Federal Preliminary FUR                           resources of the Bering Sea and Aleutian Islands
                       For crab resources, minimum size limit is the           region. The ex-vessel value of this resource was
                    primary management measure, as is the prohibition          $326 million in 1990 and $294 million in 1991.




                    Shellfish Resources                                                                                          65






                 22. KING CRABS

                                                       
                                                              











                                                                                                      





                                                                                                           
                                            
                           
                            

                                                


                                                









                                                                                                          


                                                                                                                   Photo: AFSC

                   Three species of king crab are harvested in
                the Bering Sea/Aleutian Islands region. These                              King Crab
                am the red king crab (Paralithodes                              Bering Sea and Gulf of Alaska
                camtschaticus), the blue king crab (P. platypus),
                and the brown or golden king crab (Lithodes              Catch (1,000 t)          Abundance (Millions)  
                aequispina). The red king crab fishery has the
                longest commercial history and highest yield
                and value when compared to the other two king
                                                                                                                                        crab species. Ex-vessel value of king crab
                landings declined 38%, from $132 million in
                1990 to $82 million in 1991.                                                                      

                Red King Crab
                                                                         

                   Red king crabs are distributed in the shelf
                waters of the North Pacific and Bering Sea from         
                                                                                                                         100

                may attain carapace lengths in excess of 200 mm
                the Japan Sea to northern British Columbia, and

                (8 in). The minimum size limit is usually                 1960 1965   1970  1975  1980   1985 1990
                165 mm (6.5 in) carapace width, and individuals                               Year
                in the catch commonly average 2.5-3.0 kg (6-7
                lb). For most stocks, male and female size at                   Catch (BS)           Catch (GOA)
                50% maturity is considered to be 120 mm and                     Abundance (BS)


                66                                                                               Shellfish Resources
 








                   90 mm carapace lengths, respectively (4.7, 3.5 in).   199 1. Prerecruit male abundance in 1991 declined
                   Corresponding approximate ages of maturity are        from 10 to 6 million crabs. The abundance of
                   6 and 5 years.                                        mature females declined from 18 to 13 million crabs,
                     Four stocks of red king crabs are identified for    and the spawning stock remains below average.
                   management in the Bering Sea/Aleutian Islands         Fishing mortality on the mature stock in 1990 was
                   region: the Bristol Bay, Norton Sound, Dutch          below F,.,.
                   Harbor, and Adak stocks. Fisheries are conducted
                   primarily in the fall and winter. Red king crab       Dutch Harbor stock -- The Dutch Harbor red king
                   landings decreased 16% from 9,721 t in 1990 to        crab fishery has been closed since 1982 when 196 t
                   8,178 t in 199 1, and value decreased 40% from        were landed. The 1991 trawl survey conducted by
                   $105.1 in 1990 to $54.0 million in 1991. All stocks   ADF&G indicated a low level of abundance for this
                   are at low levels of abundance compared to historic   stock. Based on the continuing low stock condition
                   levels.                                               observed in 1987, 1990, and 1991 ADF&G surveys,
                                                                         the fishery remained closed in 199 1.
                   Bristol Bay stock - The 1991 catch of red king crab
                   in Bristol Bay decreased 16% Erorn 1990 (9,236 t to                    RED KING CRAB
                   7,792 t), and remained below average for this stock,           Bering  Sea/Aleutians Region
                   and substantially below the record high production               Commercial Landings (t)
                   of 59,OW t in 1980. Effort by 302 vessels making      YEAR   Bristol Dutch Adak Norton           TOTAL
                   324 landings during the 1- 8 November season                    Bay    Harbor           Sound
                   decreased 13% from 1990 (262,131 to 227,555 pot       -------------------------------------------
                                                                         1983         0       0    .899    183      1,082
                   lifts). The CPUE (number of legal crabs per pot lift) 1984     1,897       0    620     193      2,710
                   remained unchanged at 12.                             1985     1,894       0    411     208      2,513
                      The 1991 NUFS summer survey indicated that         1986     5,168       0    323     235      5,726
                   abundance declined from the 1990 level. The           1987     5,574       0    551     159      6,284
                                                                         1988     3,351       0    711     113      4,175
                   abundance of males greater than 109 mm and            1989     4,656       0    507     120      5,283
                   females greater than 89 mm carapace length,           1990     9,236       0    376     109      9t721
                   corresponding approximately to the mature stock,      1991     7,792       0    431       15     8,178
                   was 31 million male crabs in 1991 compared to         1992     3,629       0    n.a.      58
                   37 million in 1990. The stock of legal males
                   increased from 9 million in 1990 to 12 million in



                                                                IUW KING CRAB
                                                        Bering Sea/Aleutians Region



                                                                Bristol           Dutch         Adak           Norton
                                                                    Bay           Harbor                        Sound
                     ------------------------------------------------------------------------------------------
                     Long-term potential catch (t)              15,948             2,653        1,395           344
                     Importance of non-                         minor              minor        minor           minor
                      commercial fishery
                     Management                                           By State of Alaska and Federal FMP
                     Status of exploitation                               All stock are fully   exploited
                     Age at 50% maturity           males        6                  unknown      unknown         unknown
                                                   females      5                  unknown      unknown         unknown
                     Size at 50% maturity          males        120                120          120             90
                     Carapace length(mm)           females      90                 90           90              70
                     Assessment method                          Spawning stock     Index        Index           Index
                     Parameters (mature    males)
                       M                                        0.3                0.3          0.3             0.3
                       F(O.1)                                   0.35               0.35         unknown         0.35
                       F(MSY)                                   =F(O.1)            =F(O.1)      =M              =F(O.1)
                       F(91)                                    0.18               unknown      unknown         0.02




                   Shellfish Resources                                                                                   67







                Adak stock -- The 1991 red king crab catch of 371 t                      BLUZ XING CRAB
                at Adak remained similar to the 1990 catch and                    Bering Sea/Aleutians Region
                remained below high production levels of the 196N                   COMMERCIAL LANDINGS (t)
                and 1970s. Effort by seven vessels making 24
                landings during the I November-15 February season            Year   Pribilofs St.Matthew       Total
                increased 7% over 19% (10,674 to 11,407 pot lifts).          ------------------------------------
                Catch per unit effort decreased Erom 14 to 12.               1983        995       4,288       5,283
                  The Adak stock has not been surveyed since                 1984        139       1,708       1,847
                1977, but the ADF&G Mandatory Observer Program               1985        242       1,101       1,343
                instituted in 1988 provides data on stock condition.         1986        117         455          572
                                                                             1987        318         488          806
                This information indicates the stock is stable but           1988           0        601          601
                depressed in comparison to historic catch levels.            1989           0        529          529
                Fishing mortality in 1991 was unknown.                       1990           0        783          783
                                                                             1991           0      1,530       1,530
                Norton Sound stock -- The 1991 catch of red king             1992           0      1,134       1,134
                crab in Norton Sound decreased 86% from 1990
                (109 to 15 t), and was below the recent-year
                average. This amount was caught during the                       RLUZ I=r. can
                winter commercial fishery and by subsistence              Bering Sea/Aleutians Region
                permit holders. There was no summer
                commercial fishery in 1991.                                               Pribilofs     St. Matthew
                  The stock was surveyed in 1991 by NMFS.        ------------------------------------------------
                Results indicate a population of mature crabs    Long-term potential catch (t) 1,545           1,276
                of 2.1 million, down somewhat from the           Importance of non-              Minor         Minor
                2.5 million estimated in 1988. Fishing           commercial fishery
                                                                 Management                     State/        State/
                mortality in 1990 was below F,,.,.                                            Fed.FMP       Fed.FMP
                                                                 Status of exploitation         Fully-        Fully-
                Blue King Crab                                                              Exploited     Exploited
                                                                 Age at 50% maturity          Unknown        Unknown
                                                                 Size at 50% maturity males        120            105
                  Blue king crabs are distributed in the         carapace length(mm)    females      90           80
                continental shelf waters of the North Pacific    Assessment method               Index         Index
                                                                 Parameters (mature males)
                Ocem and Bering Sea from the Japan Sea to        M                                 0.3            0.3
                the waters off Southeast Alaska, although they   F(O.1)                            0.35        0.35
                do not occur in the Aleutian Islands region.     F(MSY)                       =F(O.1)       =F(O.1)
                Two stocks of blue king crabs am identified      F(91)                             0.00        0.22
                for management in the Bering Sea region: the
                Pribilof Islands stock and the St. Matthew
                Island stock. These two stocks have notice-          50% maturity for males and females is 105 min and
                ably different characteristics. Blue king crabs      80 mm carapace length, respectively. Fisheries are
                in the Pribilof Islands may attain a carapace        conducted in the fall. Blue king crab landings
                length in excess of 200 min (8 in). The              increased 95% in 1991 (783 t to 1,530 t), with
                minimum size limit is 165 mm (6.5 in)                commercial value increasing 63% ($5.8 to
                carapace width, and individuals in the catch         $9A million). Both stocks are at low levels.
                commonly average 3.0-3.5 kg (7-8 lb). Male
                and female size at 50% maturity is considered        Pribilof Islands stoc -- The blue king crab fishery
                to be 120 min and 90 mm carapace length,             around the Pribilof Islands has been closed since
                respectively. Blue king crabs Of the St.             1987 when 318 t were landed. The 1991 NMFS
                Matthew stock are smaller. The fishery is            summer survey indicated that abundance of the
                managed with a minimum size limit of                 mature stock increased over 1990 but stiff remains at
                140 mm carapace width, and individuals in            a relatively low level. Males greater than 109 mm
                the catch average 2.0-2.5 kg (4-5 lb). Size at       and females greater thaii 89 mm carapace length,


                                                                                                                     s
                6 8                                                                      Shellfish Resource









                   corresponding approximately to the mature stock,     dance was 1.5 million in 199 1, compared to
                   increased to 4.8 million crabs in 1991 compared to   0.8 million in 1990. The abundance of mature
                   4.3 million in 1990. The stock of legal males        males, used as an index of the spawning stock, was
                   increased from OA to 1.0 million crabs in 1991.      3.7 million in 1991 compared to 2.4 million in 1990.
                   Prerecruit male abundance decreased somewhat in      Fishing mortality on the mature male stock in 1991
                   199 1. The abundance of mature males, considered     was below Fy.
                   an index of spawners, was unchanged in 1991. Ile
                   stock has been at a depressed level since 1984 but, as Brown King Crab
                   indicated by prerecruit abundance, is now showing
                   some signs of recovery.                                  Brown (golden) king crabs are distributed in the
                   St. Matthew Island stock -- The 1991 blue king crab  continental slope waters of the North Pacific Ocean
                   catch around St. Matthew Island increased            and Bering Sea from Japan to British Columbia. In
                   95% over 1990 (783 t to 1,530 t) but remained                     BROWN KING
                   below average and substantially below the high              Bering Sea/Aleutians Region
                   production years 1982 and 1983. Effort by 68                  Commercial Landings (t)
                   vessels making 69 landings during the 16-20
                   September season increased 4 1 % from 1990
                   (26,264 to 37,104 pot lifts). Catch per unit     YEAR     Adak   Dutch Pribilof Northern TOTAL
                                                                                    Harbor
                   effort increased 33% (15 to 20). The 1991        ------------------------------------------------
                   NUFS summer survey indicated that abun-          1983    3,687      821       388       0      4,335
                   dance increased over the 1M level. The           1984    1,442      690         0       0      2,132
                   abundance of males greater than 104 mm and       1985    5,046      893         c       0      5,939
                                                                    1986    5,805      848         c       0      6,653
                   females greater than 79 mm carapace length,      1987    3,629      627         c      193     4,449
                   corresponding approximately to the mature        1988    4,119      701         c       73     4,893
                   stock, was 4A million crabs in 1991 compared     1989    4,610      840         c       c      5,450
                   to 2.6 million in 1990. The stock of legal       1990    2,382      780         0       0      3,162
                                                                    1991    2,837      657         0       0      3,494
                   males, 1.7 million crabs in 1990, was            c = confidential
                   2.2 million in 199 1. Prerecruit male abun-




                                                              BROWN KING CRAB
                                                        Bering Sea/Aleutians Region



                                                                 Adak       Dutch   Pribilof Northern
                                                                      Harbor

                      ----------------------------------------------------------------------------------------
                      Long-term potential catch (t)              3,146           681             0           37
                      Importance of non-                         Minor           Minor           Minor       Minor
                       commercial fishery
                      Management                                 -- By  State of Alaska and Federal   FMP --
                      Status of exploitation                     Unknown         Unknown         Under-      Under-
                                                                                                 Exploited   Exploited
                      Age at 50% maturity          males         Unknown         Unknown         Unknown     Unknown
                                                   females       Unknown         Unknown         Unknown     Unknown
                      Size at 50% maturity         males         109-130         130             107         92
                      Carapace length(mm)          females       106-113         ill             100         98
                      Assessment level                           Index           Index           Index       Index
                      Parameters (mature    males)
                        M                                        0.3             0.3             0.3         0.3
                        F(O.1)                                   Unknown         Unknown         Unknown     Unknown
                        F(MSY)                                   = M             = M             = M         = M
                        F(91)                                    Unknown         Unknown         0           0




                   Shellfish Resources                                                                                  69









                  most management areas the minimum size limit is              Stevens, B.G., R.A. MacIntosh, J.A. Haaga, and J.H.
                  152 mm (6.0 in) carapace width, and individuals in           Bowerman. 1993. Report to industry on the 1993
                  the catch commonly average 1.4-2.3 kg (3-5 lb).              eastern Bering Sea crab survey. AFSC Processed
                  Male and female size at 50% maturity is in the range         Rep. 93-14,53 p. Alaska Fish. Sci. Cent., Nad. Mar.
                  of 92-130 mm and 98- 111 mm carapace length,                 Fish. Serv., NOAA, P.O.Box 1638, Kodiak, AK
                  respectively.                                                99615.
                     Four stocks of brown king crabs are identified for
                  management in the Bering Sea/Aleutian Islands
                  region: Adak, Dutch Harbor, Pribilof Islands, and
                  Northern Bering Sea stocks. Fisheries are conducted
                  in the fall through the spring. Brown king crab
                  landings increased 10% from 1990 to 1991 (3,162 t
                  to 3,494 t), but value decreased I I% from $20.92 to
                  $18.5 million.


                  AdakjLQdL- The 1991 brown king crab catch from
                  Adak increased 19% over 1990 (2,382 t to 2,837 t).
                  Effort by 16 vessels making 206 landings during the
                  I November-15 August season increased 20% over
                  1990 (160,960 to 192,949 pot lifts). Catch per unit
                  -effort remained the same at 8 legals; per poL
                     This stock has not been surveyed. Fishing
                  mortality on the stock in 1991 was unknown.

                  Dutch Harbor stock -- The 1991 catch from the
                  Dutch Harbor brown king crab stock decreased 16%
                  from 1990 (780 t to 657 t). Effort by 11 vessels
                  making 50 landings during the I September-15
                  November season decreased 26% over 1990 (54,618
                  to 40,604 pot lifts). Catch per unit effort of legal
                  males was 8.
                     This stock has not been surveyed, and fishing
                  mortality on the mature stock in 1991 was unknown.

                  Pribilof Islands and Northern Bering Sea stocks --
                  Fisheries in these districts have been sporadic during
                  the last 10 years. No effort was expended in the
                  Northern Bering Sea in 199 1. No population
                  estimates are available for these stocks, and while no
                  estimates of F are available due to limited fishery
                  data, F is probably below F.Y.

                  For further information

                  Alasks, Department of Fish and Game. 1992. Annual
                  management report for the shellfish fisheries of the
                  Westward region, 199 1, Regional Information
                  Report 4K92-9, 216 p. Div. Comm. Fish., 2 11
                  Mission Rd., Kodiak, AK, 99615.




                  70                                                                                  Shellfish Resources





                                        23. TANNER AND SNOW CRABS

                                                         4








                                                   L
                                                                                                                lie


                                                                                               -Aww-














                                                                                                                       Photo: AFSC
                        Wo species of Chionoecetes 6rabs are harvested
                    in the Bering Sea/Aleutian Islands region: C. bairdi,           Tanner Crab; Chionoecetes
                    commonly known as the Tanner crab, and C. opilio,                  Bering Sea and Gulf of Alaska
                    commonly known as the snow crab. During the
                    1960s and 1970s C. bairdi stocks provided the major        200- Catch (1,000 t)           Abundance (Billions) 12
                    production of Chionclecetes crab. Since the early
                    1980s, C. opilio has been the major Tanner crab
                    species harvested in Alaska. Landed value of these                                                        -10
                    fisheries increased from $194 million to                   150-
                    $212 million from 1990 to 1991.                                                                           -8

                    Tanner crab                                                100-                                           -6

                       Tanner crabs are distributed on the continental                                                        -4
                    shelf of the North Pacific Ocean and Bering Sea             50-
                    from Kamchatka to Oregon. The males of this                                                               -2
                    species may attain a carapace width in excess of
                    180 min (7 in). The minimum size limit is 140 mm            0        'PT                             1 1177-0
                    (5.5 in) carapace width, and individuals in the catch         60    65     70    75    80     85    90
                    commonly average 0.9-1.1 kg (2-2.5 lb). Male and                                  Year
                    female size at 50% maturity is considered to be
                    110 mm and 90 min carapace width, respectively.                   Catch (BS)            Catch (GOA)
                    The corresponding approximate age of maturity is                  C. baircl nos         C opilio nos.
                    6 years.

                    Shellfish Resources                                                                                          71









                      Tbree stocks of Tanner crabs are identified for         Western Aleutians stock -- Tanner crab landings
                  management in the Bering Sea/Aleutian Islands               from the Western Aleutians stock in 1991 decreased
                  region: Bering Sea, Eastern Aleutians, and Western          68% below 1990 levels (22 to 7 t). Effort by five
                  Aleutians stocks. Fisheries are conducted primarily         vessels making 21 landings during the 1 November-
                  in the winter and spring. Tanner crab landings              25 March season decreased 79% from 1990 (6,204 to
                  decreased 51% in 1991 (29,416 t to 14,453 t). Ex-           1,309 pot lifts). Catch per unit effort increased from
                  vessel value of the fisheries was $47.8 million in          4 to 5. With the exception of a few of the smaller
                  1991.                                                       vessels in this district, the catch of Tanner crabs is
                                                                              considered incidental to the red and brown king crab
                  Bering Sea stock -- The 1991 catch of Bering Sea            fisheries in the same area. The current level of
                  Tanner crabs decreased 5 1 % from 1990 levels               fishing mortality on this stock is unknown.
                  (29,316 t to 14,423 t). This drop is an artifact of
                  season changes occuring in 1990. The catch has
                  actually been on an increasing trend which began in
                  1988. Effort by 258 vessels making 761 landings
                  during the 15 November-31 March season decreased
                  44% from 1990 levels (883,391 to 499,277 pot lifts).              TANNM CRAB (Chlonodamptan
                  Catch per unit effort increased from 19 to 21.                        Bering Sea/Aleutians Region
                     IMe 1991 NMFS summer survey indicated the                             Commercial Landings (t)
                  stock continued to increase as it has in the last few
                  years. The abundance of males greater than 109 MM           YEAR    Bering Sea Eastern          Western    TOTAL
                  and females greater than 84 mm carapace width,                                   Aleutian Aleutian
                  corresponding approximately to the mature stock,            --------------------------------------------
                  was 268 million crabs in 199 1, compared to                 1983          2,392         248         222    2,862
                                                                              1984            548         109         174       831
                  230 million in 1990. The mature stock has been              1985          1,430           75         74    1,579
                  increasing since 1985. The stock of legal males             1986               0          76         94       170
                  decreased from 54 million in 1990 to 46 million in          1987               0          73         19         92
                  1991. Prerecruit male abundance in 1991 was up              1988          1,003         141          64    1,208
                                                                              1989          3,181         148          68    3,397
                  from 1990 levels (79 million to 105 million). The           1990         29,316           78         22    29,416
                  abundance of mature males has likewise increased            1991         14,423           23         7     14,453
                  (133 million in 1990 to 151 million in 1991).
                  Fishing mortality on the mature stock in 1991 was
                  below F.-,
                  Eastern Aleutians stock --                           TANNER CRAB
                  The catch of Tanner crab                                 Bering Sea/Aleutians Region
                  from the Eastern Aleutians
                  stock in 1991 decreased 71%                                               Bering Sea       Eastern      Western
                  below 1990 levels (78 t to 23                                                             Aleutian Aleutian
                                                     ---------------------------------------------------------------
                  t). Effort by five vessels         Long-term potential catch W                 11,574            266          89
                  making 27 landings during          Importance of non-commercial       - ------------       Minor    -----------
                  the 15 January-31 March                     fishery
                  season decreased 73% from          Management                              -----   State/Federal FMP      ------
                  1990 (6,858 to 1,849 pot           Status of exploitation               Fully-exploited     Unknown     Unknown
                                                     Age at 50% maturity (both sexes)             6           Unknown     Unknown
                  lifts). Catch per unit effort      Size at 50% maturity (males)                 110         Unknown     Unknown
                  increased from I I to 12. A          Carapace width(mm)       (females)         90          Unknown     Unknown
                  survey of this stock by the        Assessment method                            Yield           Index      Index
                  ADF&G during summer                Assessment parameters      (mature males)
                                                       M                                          0.3              0.3          0.3
                  1991 indicated a very small          F(O.1)                                     0.34        Unknown     Unknown
                  C. bairdi population.                F(MSY)                                     = F(O.1)         = M        = M
                  Fishing mormlity in 1991             F(91)                                      0.09        Unknown     Unknown
                  was unknown.


                  72                                                                                 Shellfish Resources








                    Snow crab                                               SNOW CRAB                 aa=Q)
                                                                                       Bering Sea
                      Snow crabs (C. opilio) are distributed on
                    the continental shelf of the Bering Sea,         Stock                                 = Bering Sea
                    Chukchi Sea, and in the western Atlantic         Long-term potential catch             = 28,951 t
                    Ocean as far south as Maine. A subspecies,       Importance of non-commercial fishery  = Minor
                    C.o. elongatus, occurs from the Japan Sea to     Management                       = State/Fed.FMP
                                                                     status of exploitation           = Fully-exploited
                    the Okhotsk Sea. The males of this species       Age at 50% maturity (males & females)  =   4
                    may attain a carapace width in excess Of         Size at 50% maturity     males         = 65
                    152 mm (6 in). In U.S. waters a market           Carapace width(mm)      females        = 50
                    minimum size of about 102 mm carapace            Assessment le'vel                      = Yield
                                                                     Assessment parameters (mature males)
                    width is in effect, and individuals in the catch M                                      = 0.3
                    commonly average 0.5-0.7 kg (1-1.5 lb). Male     F(O.1)                                 = 0.25
                    and female size at 50% maturity is considered    F(MSY)                                 = F(O.1)
                    to be 65 mm (2.6 in) and 50 min (2.0 in)         F(91)                                  = 0.16
                    carapace width, respectively. Ile correspond-
                    ing approximate age of maturity is 4 years.
                       Snow crabs of the eastern Bering Sea are consid-  Stevens, B.G., R.A.          SNOW CRAB
                    ered to be one stock. Fisheries are conducted        MacIntosh, J.A.         (Chinnoecates ontlio)
                    primarily in the winter and spring. Snow crab        Haaga, and J.H.              Bering Sea
                    landings jumped 103% in 1991 (73,402 to              Bowerman. 1993.        Commercial Landings (t)
                    149,073 t), and value increased 59% ($103.6 to       Report to industry       1983          11,852
                    $164.3 million). Effort by 228 vessels making 2,788  on the 1993 eastern      1984          12,162
                    landings during the 15 January -23 June season       Bering Sea crab          1985          29,937
                    increased 53% over 1990 (911,613 to 1,391,583 pot    survey. AFSC             1986          44,445
                    lifts). Catch per unit effort increased 35% (139 to  Processed Rep. 93-       1987          46,223
                    188 legal crabs per pot lift). The 1991 NMFS         14, 53 p. Alaska         1988          60,809
                                                                                                  1989          67,793
                    summer survey indicated that the mature stock        Fish. Sci. Cent.,        1990          73,402
                    remains high. Abundance of males greater than        Natl. Mar. Fish.         1991        149,073
                    64 mm and females greater than 49 mm carapace        Serv., NOAA,             1992        143,020
                    width, corresponding approximately to the mature     RO.Box 1638,
                    stock,, was 5,215 million crabs in 199 1, compared to Kodiak, AK 99615.
                    4,748 million in 1990. Abundance of large males
                    increased from 420 million in 1990 to 484 million in
                    199 1. Prerecruit male (80-104 mm) abundance in
                    1991 decreased from 1990 (1,077 million to
                    708 million). Ile abundance of mature males
                    decreased from 1,949 to 1,640 million. Fishing
                    mortality on the mature stock in 1991 was below
                    F,,r

                    For further information


                    Alaska Department of Fish and Game. 1992. Annual
                    management report for the shellfish fisheries of the
                    Westward region, 199 1, Regional Information
                    Report 4K92-9,216 p. Div. Comm. Fish., 211
                    Mission Rd., Kodiak, AK, 99615.





                    Shellfish Resources                                                                                73





                  24. SHRIMP AND SEA SNAILS


                     The U.S. fishery for shrimp in                                                 -Q*-
                  Alaskan waters is currently at a
                  low level. The western Gulf of
                                                                                        *3
                  Alaska has been the main area of
                  operation. During the 1970s,
                  when the fishery was at a higher                                                        ot
                  level of productivity, from 50 to
                  100 vessels trawled for shrimp
                  (primarily Northern pink shrimp,
                  Pandalus borealis) off Kodiak and                                      Z          LMAA@W
                  along the Alaska Peninsula.
                                                                    4
                  Stocks are managed by regulating
                  the level of exploitation rates
                  according to the level of the
                  stocks. In addition, spring "egg
                  hatch" closures are utilized to
                  protect breeding stocks.
                    From the 1960s, catches rose
                  steadily to about 58,000 t in 1976,
                  and declined precipitously after
                  that time. Since 1988, no shrimp
                  has been landed from western
                                                                              IMP=, i@@
                  Alaska. During the 1960-90
                  period, the ex-vessel value of
                  western Alaska shrimp fisheries
                                                                                         VFW W             -@j
                  averaged $4 million annually, with
                  a peak value of $14 million in
                  1977.
                    Shrimp catches by the U.S.S.R.
                  and Japan in the Bering Sea rose                                                                    Photo: AFSC
                  to a peak of 32,000 t in 1963, and
                  gradually declined thereafter, until the fishery ceased    ture regimes.
                  operation in 1973. The potential yield for shrimp          Neptunea                       SFJL SNAILS
                  stocks is not well understood. The LTPY has been           pribiloffensis and        Bering Sea/Aleutians
                  estimated using the 20-year average catch.                 N. lyrata are             Commercial Catch (t)
                    The snail resource of the eastern Bering Sea is          typically found in
                  composed of about 15 species which are patchily            deeper, warmer            YEAR            CATCH
                  distributed over the continental shelf. Neptunea           waters at the shelf     ----------------------
                  pribiloffensis is probably the most abundant species,      edge, while N.            1982                841
                                                                                                       1983            1,207
                  with other members of the genus, N. lyrata, N.             heros and N.              1984                852
                  ventricosa, and N. heros also very common. Mean            ventricosa inhabit        1985                389
                  shell lengths for these species range from 100 to          shallower coastal         1986            1,826
                  120 mm. Fusitriton oregonensis is another abun-            waters. Neptunea          1987            3,267
                                                                                                       .1988                0
                  dant species and reaches a length of 130 mm (5.1           pribiloffensis, N.        1989                 0
                  in). Several species of the genus Buccinum are also        lyrata, and               1990                 0
                  common to the area, but they am smaller with               F oregonensis             1991                 0
                  average shell lengths ranging 58 to 75 mm. Most            make up the bulk
                  species are restricted to specific depth and tempera-      of the snail

                  74                                                                                Shellfish Resources









                     biomass in the eastern Bering Sea.
                        Life histories are similar among species. Sexes                            Shrimp and Snail
                     are separate and fertilization is internal. Among                       Bering Sea and Gulf of Alaska
                     larger species, maturity occurs at 90-110 mm                      Catch (1,000 metric tons)
                     lengths, which probably correspond to an age of                80-
                     about 10 years. Young are hatched from egg cap-
                     sules, and almost all species have no larval stages.           70       - ---
                     Egg cases are usually laid on both live and dead
                     shells of large snails, and vary in the number of              60--
                     individual capsules they contain. Little is known
                     regarding feeding habits of snails, but they are               50-
                     probably predators and scavengers.
                                                                                    40-
                        Japan has harvested snails from the eastern
                     Bering Sea since at least 1971, the last year of               30--
                     operation being 1987. The average annual catch of
                     whole animals during that period was approximately
                     4,800 L Only fragmentary information is available
                     regarding other aspects of this fishery.
                     Neptunea pribiloffensis accounted for 70% of the
                     catch and meat yields were about 30%. Probably                   0_@
                     less than 20 vessels participated in the fishery                  60     65      70      75     80      85      90
                     annually, ranging in size from 96 to 490 gross t, and                                   Year
                     similar to vessels used in Japanese longline and crab               -Shrimp (BS)       Shrimp (GOA)     Snail (13S)
                     fisheries off Alaska. Fishing gear consisted of baited
                     pots (traps) attached at intervals along
                     groundlines. Ex-vessel value in the late                                      SEA SNAILS
                     1970s ranged between $6W and                                        Bering Sea/Aleutians Region
                     $1,657 per t, with the value of the 1978
                     catch estimated at $1.3 million.
                        There is currently no U.S. fishery for             Long-term potential catch                        4,800 t
                                                                           Importance of recreational fishery            = None
                     snails in the Bering Sea, although one vessel         Management                                    = PFMP
                     was permitted to fish in 1990. There am no            Status of exploitation                   Underexploited
                     estimtes of biomass available, and fishing            Spawning stock abundance                      = Unknown
                     mortality and other population parameters             Age at 50% maturity (male and female) = 10
                                                                           Size at 50% maturity (male and female)= 90-110
                     am unknown.                                             Shell length (mm)
                                                                           Assessment method                             = History
                     For further information                               Assessment parameters                         = Unknown


                     MacIntosh, R.A. 1980. The snail resource of
                     the eastern Bering Sea and its fishery. Mar.
                     Fish. Rev. 42(5):15-20.













                     Shellfish Resources                                                                                              75





                       ALASKA SALMON RESOURCES
                       By James C. Olsen







                                                                                                  M @_@







                                                                                          4.           Ku





                                                                                                                              Photo: AFSC


                          The Pacific salmon fisheries in Alaska contrib-           freshwater rearing for Pacific salmon: (1) migration
                       ute to the food supply and economy of the Nation             to saltwater upon emergence from the gravel,
                       and rank as the largest non-governmental employer            typical of pink and chum salmon; (2) short-term
                       in Alaska with recent sales exceeding those of               rearing in fresh water with migration to sea in the
                       tourism, mining, or forest products. The fisheries           first year of life, typical of ocean-type (fall)
                       provide recreational opportunities and are an                chinook, some sockeye, and some chum popula-
                       integral part of Alaska native culture and heritage.         tions; and (3) at least one winter rearing in fresh-
                       Recent catches exceed 155 million salmon and                 water streams or lakes after emergence with
                       include about 20 million salmon from the Alaska              migration to sea at age I or older-, typical of coho,
                       enhancement projects. Ex-vessel value of the 1992            stream type (spring) chinook, and most sockeye
                       catch was about $575 million.                                populations.
                          Pacific salmon are anadromous. Their life cycle              In the North Pacific Ocean, salmon from Alaska
                       begins with the deposition of eggs by spawning               feed with other North American stocks and migrate
                       adults in redds (nests) dug in streambeds or lake            thousands of miles and mix with stocks from Asia.
                       bottoms. Some pink and chum populations spawn                Some stocks will migrate into international waters
                       in or just above intertidal areas. Eggs incubate             outside of the U.S. EEZ. Length of stay in the
                       several months in the gravel before the young                ocean varies with species from 1 year to 6 years.
                       salmon (alevins) are ready to hatch. After hatching          Pink and coho salmon typically spend one winter at
                       the alevins remain in the gravel nourished by the            sea; chum and sockeye salmon spend from 2 to
                       egg yolk before emerging from the gravel as ready-           5 years; and chinook salmon may spend up to
                       to-feed salmon fry. There are three basic patterns of        6 years. Growth in ocean areas is rapid. Average


                       Alaska Salmon Resources                                                                                            77








                 weight at maturity is 3-5 lb for pink, 5-8 lb for             In Alaska, all five species of Pacific salmon are
                 sockeye, 10-15 lb for chum, 7-12 lb for coho, and         fully utilized. Most stocks have generally rebuilt to
                 17-50 lb for Chinook salmon. As Alaska stocks             or beyond previous high levels. On a regional basis,
                 return to natal spawning areas, they mix with stocks      some stocks are not rebuilding and may be overuti-
                 from British Columbia, the Yukon Territory and the        lized and may be at risk. Declining escapement of
                 Pacific Northwest along the Alaska coast.                 some stocks in the three ADF&G management
                    Management of Pacific salmon in the vast               regions (southeast, central, and western) has been
                 Alaska region requires a complex mixture of               observed. The reasons for the declines are not fully
                 domestic and international bodies, treaties, regula-      understood but causes may include impacts on
                 tions, and agreements. Salmon management in the           spawning and rearing habitats from industrial
                 EEZ is under the responsibility of NMFS and the           activities, decreasing ocean temperatures, reduced
                 NPFMC for the coast of Alaska from 3 to 200 miles         food abundance at early life stages, bycatches in
                 offshore. In state waters, where most fisheries           other fisheries, illegal high-seas fishing, and
                 occur, fisheries are managed by the ADF&G.                competition in ocean feeding areas from Asian
                 Catches of Alaska salmon in high-seas fisheries           hatchery salmon.
                 outside the U.S. EEZ can be significant. As of
                 1993, the high-seas salmon fishery of Japan has
                 been terminated under a new "Convention for the
                 Conservation of Anadromous Stocks for the North
                 Pacific Ocean." The other type of high-seas fishery
                 that can catch significant numbers of salmon, the
                 squid-driftnet fishery, has also been terminated
                 under the United Nation's General Assembly
                 Resolution 46/215.
                    The complexity of managing fisheries on
                 mixtures of salmon stocks from several regions and
                 from two countries is illustrated by the Pacific
                 Salmon Treaty between the United States and
                 Canada. Signed in 1985, the Treaty established the
                 Pacific Salmon Commission (PSC) and provides
                 principles for salmon stock management to reduce
                 interceptions and to establish equity in Catches off
                 the Pacific Northwest, British Columbia, and
                 Southeast Alaska. The U.S agencies involved
                 include state management agencies in Oregon,
                 Washington, Idaho, and Alaska, Pacific Northwest
                 Indian tribal governments; and U.S. Departments of
                 State, Commerce, and Interior. Agreements from
                 the Treaty are assisting in rebuilding depressed
                 Chinook salmon stocks; in Southeast Alaska,
                 Chinook catch ceilings provide for hatchery "add-
                 ons" to allow harvest of salmon from Alaska
                 hatcheries. 71be Treaty sets catch allocations for
                 British Columbia sockeye salmon stocks caught in
                 southern Southeast Alaska traditional net fisheries.
                 Agreements have been reached on harvest alloca-
                 tions and bilateral enhancement for transboundary
                 river sockeye salmon. Pink salmon catch ceilings
                 have been set to reduce interceptions of Alaska pink
                 salmon by Canada in boundary fishing areas
                 between British Columbia and Alaska.



                 78                                                                      Alaska Salmon Resources





                                                                                  25. CHUM SALMON




                        Chum salmon (Oncorhynchw keta) have
                     the widest natural geopaphic distribution of                       CHUM SALMON CATCH
                     all Pacific salmon species. They range
                     throughout Alaskan waters from ft Southeast                                       Alaska
                     Region into the Bering Sea and to northern
                     Alaska in the Arctic Ocean to the 14ackenzie                   Millions of fish
                     River in Canada.
                        Chum salmon often spawn in large rivers                  14-
                     and stream areas where upwelling ground                                                7
                     water is present. In some arm , they can be
                     found spawning in the same places as pink
                                                                                10 -                           . ... ..
                                                                                                                7
                     salmon (0. gorbuscha) including the intertidal
                     reaches of rivers. Some chum salmon travel
                     long distances in rivers before spawning. In
                     the Yukon River, chum salmon may migrate                    B_
                     oyer 2,800 km to return to natal spawning
                     grounds.                                                    4-
                        In the fall, the female salmon lays up to                2
                     2,700 eggs in the stream gravel. After
                     hatching the. following spring, the fry usually             0
                     move downsawn and by fall have entered the                     70 72 74 76 78 80 82 84 86 88 90 92
                     ocean. 'T'hey remain in the ocean from 2 to                                           Year
                     4 years feeding in the same areas as salmon
                     fiom C;anada, Japan, and Russia. Chum                                 Southeast M Central = western
                     salmon valry in size at maturity and average
                     about 3-8 kg. Some may weigh as much as
                     20 kg.
                        Most chum salmon are caught in near-
                     shore gill net and purse seine fisheries. Catches              target species in               CBM BALM=
                     averaged between 5.4 million and 7.8 million fish              net fisheries that                  Alaska
                     until the 1980s and were generally incidental to               are directed at              COMMERCIAL CATCH
                     pink salmon catches. During the 1980s, market                  sockeye and pink              (1,000s of fish)
                     demands for chum salmon increased as the avail-                salmon and
                     ability of other salmon decreased and fresh and                spawning                   Ten Year        Average
                     frozen chum salmon from Alasb were marketed in                 escapement                   period        catch
                     Japan and northern Europe. The State of AbAn                   counts are               ---------------------
                     began hatchery production of chum salmon in the                generally inexaCL          1890-99               10
                                                                                                               1900-09              899
                     1980s. From 1990 to 1992, about 24% of the catch                 Stocks in the            1910-19           6,656
                     in the southeast and central regions has been from             western region             1920-29           7,559
                     hatcheries.                                                    may have been              1930-39           7,636
                        On a statewide basis, chum salmon populations               impacted by                1940-49           7,830
                                                                                                               1950-59           6,244
                     am fully utilized but -abundance, as reflected by              foreign high-seas          1960-69           5,386
                     catches, remains well below historic levels. The               drftet fisheries           1970-79           6,299
                     status of the wild stocks is difficult to determine.           for squid and              1980-89         11,143
                     Catch data generally do not reflect abundance of               salmon. Large              1990-92           9,214
                     this species because chum salmon are usually not a             numbers of chum
                                                                          7Fc















                                                                                    M rn













































                     Alaska Salmon Resources                                                                                            79






























              salmon were caught, but country-of-origin
              data are sparse. These fisheries ended in                          CHUM SALMON
              December 1992 with the United Nations'                               Alaska
              moratorium on pelagic driftnet fishing.
              Illegal high-seas fishing in amas where        Average catch (1980-92):       Alaska   = 38,192 t
              North American salmon occur remains a                              Southeast  region   = 10,771 t
                                                                                   Central  region   = 13,339 t
              concern and has an unknown impact on                                 Western  region   = 14,082 t
              stocks. More research is needed to establish
              baseline data so that Pacific Salmon of North  Average catch (1990-92):       Alaska   = 31,668 t
              American and Asian origin can be identified                        Southeast  region   = 12,537 t
                                                                                   Central  region   =   7,831t
              and to increase understanding of distribution                        Western  region   = 11,300 t
              and competition with other species in ocean
              feeding arm.                                   Long-term potential yield (MSY):
                Conservation of some stocks in the                                          Alaska   = 38,192 t
                                                                                 Southeast region    = 10,771 t
              southern southeast region, is a concern where                        Central  region   = 13,339 t
              lower-thm-average returns to spawning                                Western  region   = 14,082 t
              areas have been observed and runs have not
              rebuilt to historic high levels as have pink   Harvesting strategy           =   Escapement goals
                                                             Age/length at recruitment     =   3 yrs/55 cm
              salmon in the same region. Reasons for the     Age/length at 50% maturity    =   4-5 yrs/63-71 cm
              declines are not fully understood but may be   Maximum age                   =   6 yrs
              due to changes in ocean growth and survival,   Abundance and trend           =   Relatively
              overharvesting of stocks by coastal fisheries,                                   stable
                                                             Importance of recreational   fishery = Minor
              and degradation in freshwater habitats.        Management                    = State and FMP
                                                             Status of exploitation        = Fully exploited



                                                             Southeast region = east of long. 144* W.
                                                             Central region = Prince William Sound, Cook
                                                              inlet, Kodiak, and south of Alaska Peninsula.
                                                             Western region = north of Alaska Peninsula.



              80                                                             Alaska Salmon Resources





                                                                                           26. PINK SALMON




                           The pink salmon (Oncorhynchm
                       gorbuscim) is often the "bread and butter"fish                          PINK SALMON CATCH
                       in many coastal communities because of their
                       abundance in much of Alndra Commercially                                                Alaska
                       important runs of this salmon occur in the
                       southeast and central regions; Bristol Bay, in                 140- Millions of fish
                       the western region, is the northern limit of
                       loge runs. This salmon is also popular with                    120-
                       sport fisheries and it is important to subsis-
                       tence users in Alaska                                          100-
                          The pink salmon is the smaUest, of the
                       Pacific salmon in Alaska Maturing salmon                       so-
                       return to spawn in natal streams after
                       18 months in the ocean (2 years old). A                        00-
                       female lays 1,5@2,000 eggs. Mon spawning
                       occurs in freshwater streams within a few                      40--
                       miles of the coast and intertidal spawning is
                       also common. The pink salmon is the only                       20  -
                       Pacific salmon having a fixed 2-year life span
                       and salmon spawning in odd-numbered years                        0.
                       are reproductively isolated from even-yem                          TO 72 74 70 78 80 82 44 88 88 90 92
                       spawning fish. Frequently, in a particular                                                 Year
                       stream. one cycle will dominate over the other.
                       In other streams, each cycle may have similar                             Southeast M Contra[ =3 Western
                       abundance. Soon after emergence, the young
                       fry migrate to the ocean.
                          Most pink salmon are caught commercially
                       in purse seines and gill nets. Historic records
                       show that catches peaked in the 1930s and 1940s
                       and then declined to low levels into the 1970s.                    of wild and                     Pin SALK=
                                                                                                                              Alaska
                       Since 1975, the runs have been rebuilt through                     hatchery popula-              COMMERCIAL CATCH
                       management efforts, hatchery production, and                       tions to Prince               (1,000s of fish)
                       favorable ocean survival. Harvest levels peaked in                 William Sound am
                       1991 at a record 128 million fislL In 1992, catches                not fully under-            Ten Year          Average
                       decreased to 00 million fish with reduced returns to               stood. LOW                  period             catch
                       several districts.                                                 survival of the           ----------------------
                          Hatchery production in Southeast and Central                    IM year class               1890-99            1,217
                       Ala.*a contributes significantly to the total catch.      In       my be linked to             1900-09            8,338
                                                                                                                      1910-19           28,293
                       the 1990-92 period, hatchery-produced pink salmon                  effiects; of low water      1920-29           36,118
                       provided 24% of the catch. About 90% of the                        temperatures on             1930-39           53,960
                       hatchery produced catch was from Prince William                    food abundance              1940-49           49,129
                       Sound.                                                             and fry growth and          1950-59           20,880
                                                                                                                      1960-69           29,840
                                                                                                                         n
                                                                                                                         11.1
                                                                                                                         1"A
                                                                                          W1111111111                                   I



                          On a statewide basis, pink salmon populations                   possible latent             1970-79           26,045
                       are fully utilize& Most stocb appear to have rebuilt               effects from the            1980-89           68,730
                       to or beyond previous high levels as judged by catch               1989 oil spill in the       1990-92           91,614
                       datL Reasons for the unexpected low return in I M                  Sound. There is


                       Alaska Salmon Resources                                                                                                   81






























              also concern that decreased spawmng escape-
              ments in wild stocks may be due to interactions                    PINK SALMON
              of hatchery releases and returns with wild fish.                       Alaska


                                                             Average catch (1980-92):      Alaska   = 113,225  t
                                                                                 Southeast region   =   48,610 t
                                                                                   Central region   =   58,396 t
                                                                                   Western region   =    6,218 t


                                                             Average catch (1990-92):      Alaska   = 127,284  t
                                                                                 Southeast region   =   57,251 t
                                                                                   Central region   =   68,413 t
                                                                                   Western region   =    1,621 t


                                                             Long-term potential   yield (MSY):
                                                                                           Alaska   = 113,225  t
                                                                                 Southeast region   =   48,610 t
                                                                                   Central region   =   58,396 t
                                                                                   western region   =    6,218 t


                                                             Harvesting strategy           =  Escapement goals
                                                             Age/length at recruitment     =  2 years/50-61 cm
                                                             Age/length at 50% maturity    =  2 years/50-60 cm
                                                             Maximum age                   =  2 years
                                                             Abundance and trend           =  Stable
                                                             Importance of recreational   fishery = Major
                                                             Management                    = State and FMP
                                                             Status of exploitation        = Fully exploited



                                                             Southeast region = east of long. 144* W.
                                                             Central region = Prince William Sound, Cook
                                                              Inlet, Kodiak, and south of Alaska Peninsula.
                                                             Western region = north of Alaska Peninsula.



              82                                                              Alaska Salmon Resources






                                                                   27. SOCKEYE SALMON




                        The sockeye or red salmon
                     (Oncorhynchus nerka) is Alaska's most                       SOCKEYE SALMON CATCH
                     valuable salmon. It occurs throughout
                     much of Alaska and supports commercial                                        Alaska
                     fisheries in Bristol Bay and Central and                    Millions of fish
                     Southeast Alaska                                        
                        Sockeye salmon spend from 2 to 4 years
                     in the ocean. Spawning occurs generally in              
                     late summer and fall in freshwater rivers
                     and lakes. The young Ely normally spend                 
                     from I to 2 years in lakes before migrating
                     in the spring to the ocean. In some stocks.             
                     the firy stay in the rivers only and migrate to
                     salt water before die first winter.                     
                        Most sockeye salmon are caught com-
                                                                                                                     
                     mercially in nearshore fisheries with gill              
                     nets and purse seines. Except for a small
                     percentage of sockeye salmon caught in the              
                     EEZ all fisheries occur in state waters and
                     the resource is managed by the ADF&G. In                
                     Southeast Alaska sockeye salmon fisheries                   70 72 74 76 78      80 82   84 86 88 90 92
                     Dear transboundary rivers and the U.S.-                                          Year
                     Canada, border am managed in compliance                                             
                     with the Pacific Salmon Treaty between the                        Southeast  Central  Western
                     United States and Canada. Sockeye salmon
                     from British Columbia occur in varying
                     numbers each year in Southeast Alaska               
                     waters where some are caught in U.S. fisheries.
                        The area with the largest production of sockeye         the Cook Inlet and          SOCKEYE SALMON
                     salmon is Bristol Bay in the western region. In             Kodiak Island                     Alaska
                     recent years, about 60% of the total catch in the state     areas.                      COMMERCIAL CATCH
                     has come from Bristol Bay.                                     Stocks in the            (1,000s of fish)
                        Sockeye salmon catches were low in the mid-              three regions are
                     1970s, but subsequently increased and reached a             fully utilized. most          Ten Year         Average
                     high of 52.7 million fish in 1983 as stocks rebuilt.        stocks appear to be         period           catch
                     The IM catch of 583 million fish is an all-time             rebuilt from           ----------------------
                     record. The recent 1990-92 average catch was                previous low levels       1890-99           1,479
                     52.0 million fish. Sockeye salmon from hatcheries           and are productive        1900-09          20,853
                                                                                                           1910-19          26,826
                     and lake stockings are now a significant part of            with recent yields        1920-29          23,679
                     catches in some areas. Returns from enhancement             at or above 13-year       1930-39          25,321
                     projects in the southeast and central regions made up       average& Near-            1940-49          17,230
                     about 12% of the catch in 1992. From 1990 to 1992,          record catches in         1950-59          10,990
                                                                                                           1960-69          13,230
                     the avenge contribution from enhancement to                 1992 were recorded        1970-79          13,626
                     commercial catches was 20%. Much of the en-                 in Bristol Bay and        1980-89          37,094
                     hanced production is from returns to hatcheries in          off Kodiak Island         1990-92          52,021



                     Alaska Salmon Resources                                                                                        83
 

























                                           jv













                while man y other areas had above-average
                catches. One area with lower than average                           SOCXM SALMON
                returns of wild stocks has been Prince William                            Alaska
                Sound.

                                                                  Average catch (1980-92):       Alaska   =   109,025  t
                                                                                       Southeast region   =      4,692 t
                                                                                        Central  region   =    30,731  t
                                                                                        Western  region   =    73,602  t


                                                                  Average catch (1990-92):       Alaska   -   138,885  t
                                                                                      Southeast  region   =      6,348 t
                                                                                        Central  region   =    40,512  t
                                                                                        Western  region   =    92,025  t


                                                                  Long-term potential yield     (MSY):
                                                                                                 Alaska   =   109,025  t
                                                                                      southeast region    =      4,692 t
                                                                                        Central  region   =    30,731  t
                                                                                        Western  region   =    73,602  t


                                                                  Harvesting strategy             =   Escapement goals
                                                                  Age/length at recruitment       =   4 years/50 cm
                                                                  Age/length at 50% maturity      =   5 years/60-70 cm
                                                                  Maximum age                     =   6 years
                                                                  Abundance and trend             =   Stable
                                                                  Importance of recreational     fishery = Minor
                                                                  Management                      = State and FMP
                                                                  Status of exploitation          = Fully exploited



                                                                  Southeast region = east of long. 144* W.
                                                                  Central region = Prince William Sound, Cook
                                                                   Inlet, Kodiak, and south of Alaska Peninsula.
                                                                 .Western region = north of Alaska Peninsula.




                84                                                                  Alaska Salmon Resources





                                                                                   28, COHO SALMON




                         Coho Salmon (Oncorhynchus kisutch),
                      the third largest spmes of Pacific salmon,                        COHO SALMON CATCH
                      are found dmughout Alaska The species is                                          Alaska
                      most abundant in the central and southeast
                      regions of the sm. Maturing coho salmon                      Millions of fish
                      enter fresh water from August through
                      November to spawn in a myriad of small
                      Streams as well as Inc rivers. Spawrting
                      typically takes place in Alaska from late
                      September through January when females
                      deposit from 2AW to 4,500 eggs. The
                      juveniles spend one, two, or three winters in
                      fresh water and then migrate to the ocean to              4
                      spend about 18 months before returning to
                      their freshwater stream of origin.
                         Troll and net fisheries for coho salmon in
                      Alsi-ka now land over 5 million fish annu-
                      ally. Coho salmon are also an important
                      sport fish in marine and fresh water with
                      about 300,000 fish taken each year. Catches                 0-
                      have increased greatly since the mid-1970s.                  70 72 74 76 78        80 82 84 86 88 90 92
                      In 1975, the statewide harvest was about                                             Year
                      I million fish; since 1980, catches have
                      ranged from 3.1 to 7.0 million fish. About                           Southeast M Central              western
                      5% of the catch is currently from the EEZ
                      troll fishene& Management is conducted by
                      the State of Alaska in nearshore waters and
                      by the NMFS in the EEZ. Coho salmon from
                      hatcheries and lake stockings made up about 14% of            driftnet fishing,               WHO SALUM
                      the 1990-1992 catch in the southeast and central              but illegal fishing                  Alaska
                      regions. Since 1986,-enhanceinent has produced 8-             continues in areas            COMMERCIAL CATCH
                      179b of the catches in the two regions.                       where North                   (1,000s of fish)
                         The status of coho salmon stocks in the state is           Amenqm salmon
                      apparently good when judged by recent catch levels.           feed. The full              Ten Year         Average
                      All stocks appear to be fully utilized and in most            impact of Woo                 period           catch
                      management arm, the stocks yield good catches.                high-sm fishing           ----------------------
                      Status of stocks remains difficult to assess because it       on coho salmon              1890-99               380
                                                                                                                1900-09               659
                      is difficult to identify individual populations in            will be unknown             1910-19            1,620
                      catches and viirtually impossible to detemme                  until mom infor-            1920-29            2,120
                      spawning escapements of coho salmon in the                    mation is obtained          1930-39            2,360
                                 of spawning arm.                                   on stock identifica-        1940-49            3,099
                                                                                                                1950-59            2,091
                         Them is concern that some stocks may have been             tion, ocean                 1960-69.           1,856
                      impacted by foreign high-seas pelagic driftnet                distributions, and          1970-79            1,837
                      fishmg Jin ocean areas where North Ammm coho                  feeding arm.                1980-89            4,595
                      Salmon mix with salmon from Asia. A 1992 United                  Other activities         1990-92            5,653
                      Nations resolution now bans pelagic high sm                   mayimpact


                      Alaska Salmon Resources                                                                                             85


























                                      @R













                spawning and rearing habitat of coho
                salmon. Large areas of Alaska's wetlands                               COHO S&MON
                are Presently undisturbed and pristine and                                Alaska
                Provide habitat critical to anadromous
                fishes. Concerns exist in some areas over         Average catch (1980-   192):      Alaska   =  16,069 t
                loss of Ereshwater habitat. In the southeast                            Southeast   region   =  6,679  t
                region, logging in the Tongass National                                   Central   region   =  5,545  t
                Forest and on state and native lands has                                  Western   region   =  3,844  t
                impacW coho salmon habitat. Greater               Average catch (1990-92):          Alaska   =  17,829 t
                protection to salmon habitat is offered by                              Southeast   region   =  8,337  t
                recent legislation that requires that stream-                             Central   region   =  5,501  t
                sides be protected and that buffer strips of                              Western   region   =  3,991  t
                standing timber be left along streams to          Long-term potential yield (MSY):
                protect spawning and rearing habitats.                                              Alaska   =  16,069 t
                                                                                        Southeast region     =  6,679  t
                                                                                          Central   region   =  5,545  t
                                                                                          Western   region   =  3,844  t


                                                                  Harvesting    strategy          =   Historical catch
                                                                  Age/length at recruitment       =   3 years/55 cm
                                                                  Age/length at 50% maturity      =   4 years/74 cm
                                                                  Maximum age                     =   5 years
                                                                  Abundance and trend             =   Stable
                                                                  Importance of recreational     fishery = Major
                                                                  Management                      = State and FMP
                                                                  Status of exploitation          = Fully exploited



                                                                  Southeast region = east of long. 144* W.
                                                                  Central region = Prince William Sound, Cook
                                                                   Inlet, Kodiak, and south of Alaska Peninsula.
                                                                  Western region = north of Alaska Peninsula.




                86                                                                  Alaska Salmon Resources





                                                                          29, CHINOOK SALMON




                          The chinook or king salmon
                      (Oncorhynchus tshawytscha) is the largest of
                      the ftcific salmon with some adults reach-                          CHINOOK SALMON CATCH
                      ing a weight of 45 kg. Chinook salmon are                                              Alaska
                      found throughout most of Alaska hUjor
                      populations return to the Yukon,                             1000-  Thousands of fish
                      Kuskokwim, Nushagak, Susitna, Kenai,
                      Copper, Alsek, Taku, and Stikine Rivers.
                      Important runs also origin= from numerous                    800--
                      smalterrivers.
                          Alaska rivers normally have a single run
                      of spawning chmook salmon which lasts                        600-
                      from May through July. Adults return to
                      Eresh water after 2 to 5 years. Females
                                                                                   400-
                      deposit Erom 3,000 to 14,000 eggs which
                      hatch in late winter or early spring. Most
                      juvenile chinook salmon remain in fresh                      200-
                      water until the spring following hatching
                      and then migrate to the ocean,
                          Chinook salmon migmte long distances                        0   -
                      in the North Pacific Ocean. Salmon caught                           70 72 74 76 78 80 82 84 Be so 90 92
                      in the southeast and central regions of the                                               Year
                      Gulf of Alaska am from natural spawning
                      and hatchery production facilities in Alaska,                            Southeast    M central      M Western
                      British Columbia, Washington, and Oregon.
                      The many fisheries and stocks along the
                      coast from the Pacific Northwest to South-
                      east Alaska are managed to rebuild stocks
                      under terms of the Pacific Salmon Treaty. Recent                ment is directed at
                      data show that some indicator stocks of chinook                 achieving escape-              CEMOCK
                      salmon in the Treaty area are not responding to                 ment goals,                          Alaska
                      rebuilding efforts. Stocks of concern in Southeast              reducing inciden-              COMMERCIAL CATCH
                      Alaska include those in Behm Canal and the                      tal harvests, and              (1,000s of fish)
                      traiisboundary rivers.                                          increasing
                          Most commercial catches are made by troll and               production                   Ten Year          Average
                      gill-net fisheries on mixed stocks in nearshore areas.          through enhance-               period            catch
                                                                                                                 ----------------------
                      Total statewide catch has averaged about 684,OW                 ment. Recent                 1890-99                47
                      fish annually between 1980 and IM. This catch                   decreases in                 1900-09                207
                      includes about 80,OW Chinook salmon produced by                 harvests in the              1910-19                528
                      hatcheries in Southeast and Central Ahaska- The                 western region               1920-29                738
                                                                                                                   1930-39                766
                      chinook salmon in Alsksksk is highly prized world-              rcflect weaker               1940-49                654
                      wide by sport fishers who travel to Alaska seeking              returns to Bristol           1950-59                616
                      wild am fishing experiences. About 134,WO                       Bay and the                  1960-69                556
                      chinook salmon am caught annually in the sport                  Lower Yukon                  1970-79                617
                                                                                                                   1980-89                694
                      fisheries.                                                      River arm. In                1990-92                625
                          AD stocks in Alaska are fully utilized. Manage-             Bristol Bay, the


                      Alaska Salmon Resources                                                                                                87
                                                                                                                                     r-T
                                                                                                                                 F































                1991 return was below average for the sixth con-             Dahlberg, M. L. 1990. The high seas salmon
                secutive year.                                               fisheries of Japan, 1989. Alaska's Wildlife,
                    Some Alaska stocks may have been reduced by              ADF&G, 22(4):25-26,40-41.
                foreign high-seas pelagic driftnet and trawl fishing.
                International agreements now restrict or limit high-         Eggers, D. M. [editor] 1989. Alaska commercial
                seas fisheries in ocean areas where North American           salmon catches, 1878-1988. Alaska Dep. of Fish and
                chinook salmon occur, but illegal fishing stW                Game, Regional Info. Rep. No. 5J89-04, 69 p.
                remains a concern. High-seas catch data remain
                incomplete and more research is needed to establish          Geiger, H. J., and H. Savikko. 1991. Preliminary
                baseline data so that Pacific salmon of North                forecasts and projections for 1991 Alaska salmon
                American and Asian origin can be identified and              fisheries and summary of the 1990 season. Alaska
                their ocean distribution determined. In U.S.                 Dep. of Fish and Game, Regional Info. Rep. No.
                groundfish fisheries, some chinook salmon are taken          5J91-01, 70 p.
                incidentally in the Bering Sea, Gulf of Alaska and
                off the Pacific CoasL The NPFMC continues to                 Geiger, H. J., and H. Savikko. 1992. Preliminary
                work with the U.S. industry to reduce chinook                forecasts and projections for 1992 Alaska salmon
                salmon bycatches.                                            fisheries and review of the 1991 season. Alaska Dep.
                                                                             of Fish and Game, Regional Info. Rep. No. 5J92-05,
                For further information                                      74 p.

                Benton, D. 1990. Alaska and the fisheries of the             Groot@ C., and L. Margolis [editors]. 199 1. Pacific
                North Pacific and Bering Sea. Alaska's Wildlife,             salmon life histories. UBC Press, Vancouver, B.C.,
                ADF&G, 22(4):13-23.                                          564 p.





                88                                                                        Alaska Salmon Resources








                   McNair, M., and J.S. Holland.                                 c=OOX SAIXON
                                                                                      Alaska
                   1993. FRED 1992 annual report
                   to the Alaska State Legislature.      Average catch (1980-92):         Alaska  =   5,668 t
                   Alaska Dep. of Fish and Game,                              Southeast   region  =   2,031 t
                   Annual Rep. No. 127,                                          Central  region  =      805t
                   102 p.                                                        Western  region  =   2,832 t

                   McPhail, J. D., and C. C.             Average catch (1990-92):         Alaska  =   4,830 t
                                                                              Southeast   region  -   2,179 t
                   Lindsey. 1970. Freshwater fishes                              Central  region  -      750t
                   of northwestern Canada and                                    Western  region  =   1,901 t
                   Alaska. Fish. Res. Board Can.,
                   Bull. 173, 381 p.                     Long-term potential yield (MSY):
                                                                                          Alaska. -   5,668 t
                                                                              Southeast   region  =   2,031 t
                   Meehan, W.R. [editor]. 1991.                                  Central  region  =      805t
                   Influences of forest and rangeland                            Western  region  =   2,832 t
                   management on salmonid fishes         Harvesting strategy           =   Catch ceilings
                   and their habitats. American          Age/length at recruitment     =   4 years/60 cm
                   Fisheries Society Special Publica-    Age/length at 50% maturity    =   5-6 years/60-90 cm
                   tion 19, 51p.                         Maximum age                   =   7 years
                                                         Abundance and trend           -   Relatively stable
                                                         Importance of recreational    fishery = Major
                   North Pacific Fishery Manage-         Management                 = State, FMP, Prohibited
                   ment Council. 1990. Fishery                                        species catch amount
                   management plan for the salmon                                                   (Groundfish FMPs)
                   fisheries in the EM off the coast     Status of exploitation     - Fully exploited
                   of A laqka. N. Pac. Fish. Manag.
                   Council, P. 0. Box 1031316,           Southeast region = east    of long. 144* W.
                   Anchorage, Alaska 99510.              Central region = Prince    William Sound, Cook
                                                           Inlet, Kodiak, and south of Alaska Peninsula.
                                                         Western region = north of Alaska Peninsula.






























                   Alaska Salmon Resources                                                                              89





                     MARINE MAMMALS
                     By Howard W. Braham

























                                              @N
                                                                    o
                                            ;t












                                                                                                          Illustradw: Katwine Zooca

                        This section of the report presents information on     calf-rearing seasons in higher latitudes.
                     selected marine mammals off Alaska. Forty two                IMere are several populations of marine mam-
                     species of marine mammals in U.S. waters of the           mals that only spend a portion of the year in Alaska
                     North Pacific Ocean are under the jurisdiction of the     waters, such as humpback whales and northern fur
                     Department of Commerce. This includes 31 species          seals, whereas others are found year-round in
                     of whales, dolphins and porpoises, and 11 species of      Alaska, such as the bowhead whale. These zoogeo-
                     seals and sea lions. Most marine mammals make             graphic differences have led to varying life history
                     long-distance migrations or move hundreds of miles        strategies and result in the need to manage several
                     within smaller areas of the ocean between seasons of      populations or stocks rather than just one. Manage-
                     the year. Whales and dolphins often travel from one       ment of marine mammals is carried out under the
                     feeding ground to another or to spend the breeding        Marine Mammal Protection Act (NIMPA) of 1972
                     season in lower latitudes and the major feeding and       and the Endangered Species Act (ESA) of 1973.


                     Marine Mammals                                                                                              91













                                                                                                   STATUS OF RESIDENT AND SELECTED SPECIES
                                                                                                                           OF MARINE MAMMALS
                                                                                                                                   OFF ALASKA I
                                                                                                        (e)=endangered; (Q--threatened; (d)--depleted


                                            Species                                 Abundance                          Trends                          Method of                        Assessment                           Status and
                                                                                      (954 C.I.)                         (+/-%)                        Assessment                        Coverage                            Authority
                                            ------------------------------------------------------------------------------------------------------
                                            Bowhead                             7,500                                  +3.1/yr                         Ice-based                         Complete                            Below OSP
                                                whale                           (6,400-9,200)                          (1978-88)                       counts                                                                ESA (a)

                                            Gray whale                          20,869                                 +3.3'b/yr                       Land-based                        Complete                            Recovered
                                                                                (19,200-22,700)                        (1968-88)                       counts                                                                ESA W

                                            Humpback                            >2,000                                 Unknown                         Photographic                      Partial                             Below OSP
                                                whales                                                                                                 mark-recap.                                                           ESA (a)

                                            Killer whale                        >300                                   Unknown                         Individual                        Partial                             Uncertain
                                                                                                                                                       counts                                                                MWA


                                            Beluga                              15,800-18,450                          Unknown                         Aerial and                        Partial                             Uncertain
                                                                                                                                                       land-counts                                                           HMPA

                                            Dell's                              300,000-600,000                        Unknown                         Line transect                     Partial                             Uncertain
                                                porpoise                                                                                                                                                                     MMPA

                                            Harbor                              Unknown                                Unknown                                                                                               Uncertain
                                                porpoise                                                                                                                                                                     MMPA

                                            Northern                            >34,844                                -70%                            Counts on                         Complete                            Below OSP
                                                sea lion                                                               (1970-90)                       shore                                                                 ESA (t)


                                            Northern                            982,000                                -504                            Land-counts                       Complete                            Below OSP
                                                fur seal                                                               (1975-90)                       Pribilof Is.                                                          MWA (d)


                                            Harbor seal                         Uncertain                              -60*                            Land-counts                       Partial                             Below OSP
                                                                                (<100,000)                             (1976-92)                       Tugidak Is.                                                           MMPA

                                            Spotted2                            Unknown                                Unknown                         Ice-counts and                    Partial                             Uncertain
                                                seal                                                                                                   land counts



                                                Bowhead, gray and humpback whale estimates are for the                                                 entire eastern North Pacific Ocean;
                                                all others are for Alaska.
                                                Other ice-associated seals are the bearded, ribbon, and ringed seals.

                               Both Acts require that management of                                                                            Incidental Take of Selected Marine Mammals
                               marine mammals be based on the                                                                                                       In Domestic Fisheries
                               identification and enumeration of                                                                                                              off Alaska
                               populations
                               or stocks.                                                                              Species          Incidental Take                         Fishery                    10-year Trend              Impact of
                                     A summary of the status, impact of                                                                                                        (others)                                         Exploitation
                               incidental take, and desciption of                                                      ;;-a-y w--h-a-l-e  -------  U-n-k-n-o-w-n -----    C_o_a_zra__1__3_et__-n_e_r_3     -------- U-n-k-n-o-wn ---- Un__c_h_an__9e__d
                               selected stocks is described in the                                                     Killer whale                Unknown                Long-line and                            Unknown                Unknown
                               following chapters.                                                                                                                            gill-nets
                                                                                                                       Beluga whale                Unknown                Coastal gill-nets                  Increasing?                  Unknown

                                                                                                                       Dall13 porpoise             Unknown                Coastal gill-net3                        Unknown                Unknown
                                                                                                                       Harbor porpoise             Unknown                Coastal gill-nets                        Unknown                Unknown

                                                                                                                       Northern          1,023/yr (1978-85) Coastal                           gill-           Decreasing                  Unknown
                                                                                                                       sea lion <100/yr (1988-92) nets and                                    trawls

                                                                                                                       Northern                    Three(1990)                  Coastal       gill-           Decreasing                  Unknown
                                                                                                                       fur seal                                              nets and         trawls


                                                                                                                       Harbor seal                 Unknown                      Coastal       gill-                Unknown                Unknown
                                                                                                                                                                             nets and         trawls
                                                                                                                       Spotted seal                Unknown                            Unknown                      Unknown                Unknown




                               92                                                                                                                                                                          Marine Mammals





                                                                       30. BOWHEAD WHALE


                        The bowhead whale (Balaena                                        Bowhead Whale
                     mysticew) also known as Agvik by                                        Western Arctic
                     Alaskan Eskimos, is the only large
                     cetacean associated with the Arctic                Whales (Thousands of Individuals)
                     pack-ice year round. The species is          6000-
                     endemic to the Northern Hemisphere           5000
                     with three stocks in the North
                     Atlantic Ocem (East Greenland-               4000
                     Spitsbergen, Baffin Bay-Davis SL,
                     and Hudson Bay-Foxe Basin) and               3000--
                     two stocks in the North Pacific
                     (Okhotsk Sea and western North               2000-
                     American Arctic).
                        The migration of bowheads in              1000-
                     western Arctic Alaska takes place
                     from late March through June from                 0-
                     the western Bering Sea (Russia) into                    78  79  80    81    82   83    84    85   86    87    88
                     the Beaufort Sea (U.S. and Canada).                                             Year
                     Some remain in the Chukchi Sea
                     during summer. The autumn migration precedes the             NMFS was initiated in 1978 by agreement with the
                     advancing pack-ice from September to December.               International Whaling Commission.
                        Calves are born from March to July, following a              The present estimate of abundance of the western
                     13-month gestation period. Pregnancy rates vary              Arctic stock is 7,500 (95% C.I., 6,400-9,200) based
                     from 0.15 to 0.33; the calving interval is 4-5 years.        on a combined analysis of ice-based observer counts
                     Length at birth is 4-5m, 8-9m at age 1. and 13-14m           and passive acoustics data collected off Point
                     at sexual maturity (females). Age at first reproduc-         Barrow, Mmksi, during the bowhead's spring
                     tion is thought to range from 9 to 15 years. Annual          migration. Changes in estimates of abundance since
                     calf production varies from 3% to 12%, possibly              census studies began in 1978 reflect improvements
                     reflecting an unstable or highly variable ecosystem.         in the methods of data collection and analysis, and
                     Euphausfids and copepods are the principal prey, but         in an actual increase in the number of whales. Since
                     epibenthic fauna are also taken.       -                     1978, this bowhead stock has increased 3.1% (95%
                        Bowhead whales were one of the most severely              Cl., 0.1-6.2) per year based on counts of whales
                     exploited cetaceans: in the history of commercial            adjusted for periods of no-watch and bad weather.
                     whaling. The world abundance prior to commercial             Additional simulations also show that the stock has
                     whaling probably exceeded 120,000, but at its lowest         increased since 1920, just after commercial whaling
                     point, near the beginning of the 20th century, the           ended. The present size of the stock is about 40.9%
                     species totaled no more than a few thousand. In the          (95% C.I., 38-42) of its initial size (in 1848) based
                     western North American Arctic, 18,650 bowheads               on simulation and sensitivity tests of historic data.
                     were killed by Yankee whalers between 1848 and               These data suggest that the western Arctic stock of
                     1914 -- this from a population of probably less than         bowheads is recovering from commercial whaling
                     18,000-20,000 animals; over 60% of the whales were           and that it is below the population size supportable
                     killed between 1850 and 1870. Alaskan Eskimos                by the ecosystem (ie., its carrying capacity).
                     (Inuit) have used bowhead whales for subsistence for            Critical habitat may include the spring open lead
                     several thousand years. This century the take of             system from the Bering Strait to the Beaufort Sea,
                     bowheads at U.S. coastal Imlit v@llages averaged 20          the nearshore Beaufort Sea in autumn for feeding
                     whales killed per year Erom 1920 to 1969, about 40           and migration, and polynya and other open-water
                     per year from 1970 to 1977, and 22 per year between          areas within the Bering Sea pack-ice used by
                     1978 and 1990. A quota system administered by the            bowheads to overwinter.
                     Alaskan Eskimo Whaling Commission and the

                     Marine Mammals                                                                                                       93










               For further information
                                                                             Take of Dowhead. Whales
               Bockstoce, J. P, 1986. Whales, ice, and men.              by Alaskan Zsk4 a, 1978-1990
               The history of whaling in the western Arctic.                         ---- Pate of Whales    ----
               Univ. Washington Press, Seattle, WA- 400p.      Year       Ouota      Struck    Landed    Killed'
               Braham, H. W. 1989. Eskimos, Yankees, and       ---------------------------------------------
                                                               1978          20         18         12        16
               bowheads. Oceanus 32(l):54-62.                  1979          27         27         12        i3
                                                               1980          26         34         16        29
               Breiwick, J. M., L. L. Eberhardt@ and H. W.     1981          32         28         17        26
               Braham. 1984. Population dynamics of western    1982          19         19           8       13
                                                               1983          is         18         10        16
               arctic bowhead whales (Balaena mysticetus).     1984          25         25         12        22
               Can. J. Fish. Aquatic Sci. 41: 4844%.           1985          18         17         ft        13
                                                               1986          32         28         20        23
               Krogman, B., D. Rugh, R. Sonntag, J. Zeh, and   1987          32         31         22        29
                                                               1988          35         28         15        28
               D. Ko. 1989. Ice-based census of bowhead        1989          44         26         .18       18+
               whales migrating past Point Barrow, Alaska      1990          44         44         30        30+
               1978-83. Mar. Mammal Sci. 5: 116-138.
               Nerini, M. K., IL W. Braham, W. M. Marquette,     An estimate of the fate   of whales struck  and
                                                                 lost is reported to NMFS by the Alaskan
               and D. J. Rugh. 1984. Life history of the         Eskimo Whaling Commission; a *+' means that
               bowhead whale, Balaena mysticetus                 the number killed, beyond the number landed,
               (Marnmalix Cetacea). J. Zool. (London) 204:       is unknown.
               443468.


               Zeh, 1. E., 1. C. George, A. I- Raftery, and G. M.
               Carroll. 199 1. Rate of increase, 1978-1988, of
               bowhead whales, Baldena mysticetus, estimated
               form ice-based census data. Mar. Mammal Sci. 7:
               105-122.



























               94                                                                          Marine Mammals





                                                                                     31, GRAY WHALE




















                        There are two stocks of gray whales                      December to early February. There is some overlap
                    (Eschrichtius robustus) endemic to the North Pacific         with the first of the northward migrants from Baja
                    Ocean. One stock is located in the eastern North             California with the taff-end of the migration moving
                    Pacific Ocean, the stock migrates between the                south. A small number of whales do not undertake a
                    western Arctic Ocean (off the U.S., Canada, and              full migration and spend the winter in waters south
                    Russia coasts) to waters off Baja California. Ile            of Alaska.
                    second stock migrates from the Okhotsk Sea along                Gray whales are generally dark gray to black in
                    the coast of Russia, Japan, Republic of China, and           color with mottled patches of white generally formed
                    the Republic of Korm The eastern North Pacific or            from the sloughing of ectoparasitic barnacles such as
                    "CalifoniW' stock was heavily exploited, principally         Cyamus scammoni. As with other baleen whales,
                    by Yankee commercial whalers during the second               adult female gray whales reach sexual maturity at
                    half of the. 19th century, and may have been reduced         slightly greater lengths (12.95 m, standard error
                    to only a small Eraction of its pre-exploitation             (SE) = 0.11) than do males (12.43 m, SE = 0.12),
                    population size.                                             with maximum physical maturity reached at ap-
                        Gray whales in the eastern North Pacific Ocean           proximately 14.0 m in females and 13.0 m in males
                    are distributed across much of the southern Chukchi          at perhaps 40 years of age. Mean birth length is
                    and northern Bering Seas where they feed from May            4.6 m (both sexes), 7-8 m at weaning (usually 6-8
                    to November. They migrate out of the Bering Sea by           months postpartum) and at I year the young animal
                    December. Southward migrating gray whales are                is 8 m or greater. Age at sexual maturity is
                    found along the west coast of North America from             9 years (range 6-12 years) for females and 6 years
                    November to February with the majority of the                (range 5-9 years) for males' ' Mean conception date is
                    whales passing central California from early                 5 December, mean birth date is 27 January; and


                    Marine Mammals                                                                                                    95









                gestation lasts 418 days, on average.
                With an ovulation rate of 0.50/year                                 Gray Whale
                and a pregnancy rate of 0.46/year, an                          Eastern North Pacific
                adult female gray whale gives birth             Annual abundance (in thOUSS@Cls)
                about every 2 years. Estimated             25-
                survival rates range from 95% for
                adults to 89% for juveniles.               20-
                    The present size of the eastern
                North Pacific stock of gray whales is
                20,869 (19,MO-22,700). This level          15-
                is equal to or larger than the size of
                the population in 1846, estimated to       10-
                have been 15,000-20,000. The
                population has been increasing at a          5-
                rate of 33% per year (SE = 0.5%)
                since 1968, during which a subsis-
                tence catch of 167 whales per year          0   68  70   72    74   76   718   8.0  82   84   86    88   90
                (SE = 3.5) took place by the Soviet
                Union.



                For further information

                Braham, H. W. 1984. Distribution and migration of
                gray whales in Alaska, p. 249-266. la M.L. Jones,
                S. L. Swartz, and S. Leatherwood (eds.), The Gray
                whale, Eschrichtius robustus. Orlando, FL. Aca-
                demic Press, Inc.

                Braham, H. W., and G. P. Donovan (eds.). In press.
                The comprehensive assessment of gray whales,
                Eschrichtius robustus. Cambridge, U.K., Interna-
                tional Wbaling Commission (Special Issue 14).

                Reilly, S. B., D. W. Rice and A. A. Wolman. 1983.
                Population assessment of the gray whale,
                Eschrichtius robustus, from California shore
                censuses, 1967-1980. Fish. Bull., U.S. 81: 267-281.

                Rice, D. W., and A. A- Wolman. 197 1. The life
                history of the gray whale Eschrichtius robustus.
                Special Publication, Amer. Soc. Mammal. 3: 1-142.

                Rugh, D., R. Ferrero, and M. Dahlheim. 1990.
                Interobserver count discrepancies in a shore-based
                census of gray whales. Mar. Mammal Sci. 6(2):
                109-120.







                96                                                                                  Marine Mammals





                                                                   32. HUMPBACK WHALE









                                                                                                              qw- low




















                                                                                                                         Photo: AFSC



                         Humpback whales (Megaptera novaeangliae)                 Alaska at any time of year, especially in Southeast
                      occur in all oceans of the world. Like most baleen          Alqqkq but there is no evidence to suggest that any
                      whales, humpbacks annually migrate to high-                 of those individuals regularly overwinter there.
                      latitude, summer feeding grounds firom temperate or         Short-term seasonal distribution patterns have been
                      sub-tropical wintering grounds. The North Pacific           documented in Southeast Alaska and in Prince
                      humpback whale population tentatively has been              William Sound, including fairly predictable local
                      divided into three stocks, based on the relative            movements, such as those among favored feeding
                      discreetness of wintering areas: 1) the Mexican             areas. Seasonal distribution of humpbacks on the
                      stock, 2) the Hawaiian stock, and 3) the Asian stock        feeding grounds is subject to annual variability due
                      (near the Bonin and Ryukyu Islands, Japan). Some            to changes in oceanographic conditions and the
                      exchange takes place between the Mexican and                distribution and availability of prey.
                      Hawaiian stocks, which can be found in summer in               The pre-exploitation (prior to 1905) population
                      California, southeast Alaska, and the Gulf of Alaska.       size of humpback whales in the North Pacific Ocean
                      The wintering grounds of humpbacks seen in the              (western and eastern stocks) is not known, but
                      Bering and Chukchi seas is unknown, although a              estimates suggest that it may have been on the order
                      small number of whales tagged in the western North          of 15,000 whales. There has been no sequence of
                      Pacific Ocean south of Japan in the 1950s and 1960s         surveys long enough or consistent enough to detect
                      were recovered near the eastern Aleutian Islands a          trends in abundance.
                      few years after taggirig.                                      Current estimates of population size range Erom
                         Humpbacks primarily inhabit Alaska waters from           about 1,200 to over 2,000. More than 1,000 whales
                      late spring to early winter, approximately May              have been identified in Hawaii (between 1977 and
                      through December. Peak numbers of whales off                1982). Mark-recapture analyses based on photo-
                      Southeast Alaska typically occur in late August and         identification data suggest that 1,600 - 2,100 whales
                      September. Individual humpbacks may be seen in              annually visited Hawaiian waters (during the 1970s

                      Marine Mammals                                                                                                 97









                  and 1980s). No good estimates are available for the         For further information
                  number of whales on the other wintering grounds in
                  Mexico or the western Pacific. Preliminary work             Baker, C. S., S, R. Palumbi, H. Lambertson, M. S.
                  suggests there may be only a few hundred hump-              Weinrich, J. Calambokidis, and S. J. O'Brien. 1990.
                  backs outside the main Hawaiian breeding grounds.           Influence of seasonal migration on the geographic
                  The current best estimate for the eastern North             distribution of mitochondrial DNA haplotypes in
                  Pacific stock(s) is 1,398-2,040. This population size       humpback whales. Nature 344:238-240.
                  is only 8%-13% of its estimated initial size of 15,000
                  in the North Pacific in 1850 prior to commercial            Baker, C. S., and L. M. Herman. 1987. Alternative
                  whaling.                                                    population estimates of humpback whales
                     An estimated 300 to 350 humpbacks are present            (Megaptera novaeangliae) in Hawaiian waters.
                  in Southeast Alaska during summer and fall. Aerial          Can. J. Zool. 65: 2818-282 1.
                  and shipboard survey data have been used to
                  estimate that about 400 humpbacks summer in the             Baker, C. S., L. M. Herman, A. Perry, W. S. Lawton,
                  Gulf of Alaska and Prince William Sound and                 J. M. Straley, and J. H. Straley. 1985. Population
                  another 300 to 350 may summer near the Shumagin             characteristics and migration of summer and late-
                  and Semidi Islands, Alaska. The number of hump-             season humpback whales (Megaptera novaeangliae)
                  backs near the eastern Aleutian Islands is unknown          in southeastern Alaska. Mar. Mammal Sci. 1: 304-
                  but presumably small. Less than 100 sightings of            323.
                  humpback whales have been made in the Bering Sea
                  since 1975.                                                 Hammond, P. S., S. A. Mizroch, and G. P. Donovan
                     There are few reported fishery interactions with         (editors). 1990. Individual recognition of cetaceans:
                  humpback whales, such as incidental take, in                Use of photo identification and other techniques to
                  Alaska. Three humpbacks were reported to be                 estimate population parameters. Cambridge, U.K.,
                  entangled in seine nets in Prince William Sound in          Int. Whaling Comm. (Special Issue 12), 440 p.
                  the early 1980s. T@pically two or dim humpbacks
                  are reported entangled each year in gill nets and           Humpback Whale Recovery Team. 1990. National
                  buoy lines in Southeast Alaska and British Colum-           recovery plan for the humpback whale (Megaptera
                  bia. In the summer of 1987 at least seven hump-             novaeangliae) in waters of the United States of
                  backs were reported entangled in gill nets in               America. U.S. Department of Commerce, NOAA,
                  Southeast Alaska;- only one whale died. No esti-            NMFS, Washington, D.C., 82 p. (Available through
                  mates are available for the extent of unreported            the Office of Protected Resources, NMFS, NOAA,
                  incidental take, nor are estimates available for the        1335 East-West Highway, Silver Spring, MD
                  incidental take of humpbacks by commercial                  20910.)
                  fisheries in other areas of Alaska.





















                  98                                                                                     Marine Mammals





                                                                                     33. KILLER WHALE


                          The killer whale (Orcinus orca) is the largest              been subjected to significant rates of exploitation and
                     member of the dolphin family Delphinidae. The                    are not taken for subsistence. Incidental takes
                     large size, distinct dorsal fin, contrasting white and           during fishing operations are rare. Significant
                     black coloring, robust body, postocula white patch,              fishery interactions have been docurnented between
                     and ovate flippers are diagnostics. Adults range in              killer whales and sablefish in the Bering Sea and
                     length from 5 to 9 in. Dorsal fin height can be                  Prince William Sound. Between 1985 and 1987, 7
                     1.8 in in adult males and up to 0.9 in in adult females          killer whales from a resident pod of 35 were ob-
                     and sub-adult males. The genus Orcinus is consid-                served taking sablefish off fisherman's longlines.
                     ered monotypic with geographical variation noted in              The seven were later reported missing and are
                     size and coloring. Differences in call repertoires and           presumed to be dead. Fishermen sometimes shoot at
                     overlapping color patterns indicate some isolation               killer whales and use seal bombs and other explo-
                     among pods. Chromosomal and biochemical                          sives to keep the whales away from their catch.
                     evidence suggests that certain pods may be gened-                There is no estimate of abundance of killer whales in
                     cally distinct.                                                  Alaska. The total population size is probably not
                          Killer whales have been observed in all oceans              large, based on anecdotal accounts during surveys
                     and seas of the world and, although reported from                for other species. The total estimate of abundance
                     tropical and off-shore waters, they prefer the colder            for Prince William Sound, Shelikof Strait and
                     waters typically within 800 Ian of major continents.             Southeast Alaska is 286. Population estimates are
                     In Alaskan waters, they concentrate near land                    not available for the western Gulf of Alaska- Aleu-
                     masses and continental shelf waters and are found in             tian Islands, or Bering Sea and north.
                     greatest numbers in Southeast Alaska, Prince
                     William Sound, near Kodiak Island, and in the                    For further information
                     southeastern Bering Sea. They also have been seen
                     as far north as the Arctic Ocean.                                Braharn, H. W., and M. E. Dahlheim. 1982. Killer
                          Killer whales typically occur in small pods of              whales in Alaska documented in the Platforms of
                     fewer than 40 animals. Multi-pod gatherings have                 Opportunity Program. Rep. Int. Whaling Comm.
                     been noted, however, the biological significance of              32:643-646.
                     these groupings is not known. Pod composition
                     appears to remain constant for many years with little            Dahlheim, M. E. 198 1. A review of the biology and
                     intermixing of individuals among pods. At least two              exploitation of the killer whale, Orcinus orca, with
                     major types of pods have been noted. Transient pods              comments on recent sightings from Antarctica. Rep.
                     move in and out of areas typically occupied by                   Int. Whaling Comm. 31: 541-456.
                     resident pods of killer whales, but have no defined
                     "home range." Resident pods are usually found in                 Dahlheim, M. E. 1988. Killer whale (Orcinus orca)
                     one area year-round (encompassing several hundred                predation of longline catches of sablefish
                     to several thousand square miles), and are dominated             (Anoploponuifintbria) in Alaskan waters. NWAFC
                     by strong matriarchal lineages. The natural mortal-              Processed Rep. 88-14, 31 p. Alaska Fish. Sc. Cent.,
                     ity rate of killer whales is estimated to be less than           Nal. Mar. Fish. Serv., NOAA, 7600 Sand Point Way
                     5% per year, and may be as low as 1% per year,                   NE, Seattle, WA 98115.
                     suggesting that killer whales form stable and long
                     lasting family units.                                            Dahlheim, M. E., and J. Heyning. In press. The
                          Movements of killer whales are believed to be               killer whale. In S. Ridgway and R. Harrison (eds.),
                     related to the availability of prey, such as spawning            Handbook of Marine Mammals. New York, NY,
                     Pacific salmon, and the movements of seals and                   Academic Press.
                     whales. Killer whales prey on cod, herring, flatfish,
                     sablefish, and other fish. Resident pods typically
                     prey on fish, and transient pods possibly favor
                     marine mammals as prey. Killer whales have never


                     Marine Mammals                                                                                                              99





                  34. BELUGA WHALE

                      In western North America, beluga whales                   ruled OUL Lactation Can vary from 12 to 32 months,
                  (Delphinapterus leucas), also known as belukha or             but appears to last on average between 1 and 2 years.
                  white whales, are located in coastal waters of Alaska            The minimum estimated total population in
                  from the eastern Gulf of Alasksk near Yakutat Bay             Alskskn waters is 15,800 to 18,450 including about
                  north into the Beaufort Sea. Based on the potential           400-500 in the Gulf of Alaska-Cook InIeL Some
                  for geographic isolation as a result of differential          estimates are as high as 30,000 to account for
                  seasonal movements versus year-round residency,               animals offshore or not observed during past surveys.
                  there are possibly four (summer) stocks. 'Me stocks           Beluga whales are taken incidentally in commercial
                  are located in 1) Cook Inlet (north Gulf of Ahtska);          and native coastal fisheries in Alaska and for
                  2) Bristol/Kuskokwim Bays and Norton Sound/                   subsistence. Most incidental kills occur in Bristol
                  Yukon Delta (Bering Sea); 3) Kotzebue Sound and               Bay where a large salmon fishery exists. In 1983,
                  west coast of the Chukchi Sea; and 4) the eastern             27-31 belugas were found dead in Bristol Bay and 12
                  Beaufort Sea.                                                 were caught in salmon gill nets. Up to five belugas
                     North of lat. W N, belugas are closely associated          per year have been reported taken in the salmon
                  with open leads and polynya in ice-covered regions.           gillnet fishery in Cook Inlet.
                  Concentrations occur in both offshore and coastal                Only indigenous people are allowed to hunt
                  a= , which vary by season and region. Factors                 belugas. Subsistence takes occur in western Alaska
                  affecting seasonal and daily distribution include             (especially in the northern Bering Sea and Chukchi
                  extent of ice cover, prey availability, tidal conditions,     Sea), along the Russian Far East of Chukotka, and in
                  and human disturbance. Generally, beluga whales               the western Canadian Arctic Ocean (eastern Beau-
                  occupy waters associated with offshore pack-ice in            fort Sea). The estimated total kill (landed, stuckor
                  winter, and migrate in spring to warmer (100-150C)            lost) in U.S. waters and the Canadian Beaufort Sea
                  coastal estuaries, bays, and rivers to molt and to rear       exceeds more than 800 per year (based on data from
                  calves. Most of the North American population in              the 1970s and 1980s), although the precise annual
                  Alaska waters is associated with the offshore winter          total is unknown. These.animals probably come
                  areas, although year-round concentrations occur in            from the same population that winters in the Soviet
                  the Bering Strait, the southern Chukchi Sea, Bristol          and U.S. Bering Sea. Ile actual number of animals
                  Bay, and in Cook Inlet.                                       killed each year is not known because most of the
                     The duration of residence in summer coastal                villages are not monitored, and the fraction of
                  areas varies from a few days to several months, and           whales that die after being stuck is also unknown.
                  most belugas usually remain in densely concentrated           The number of belugas incidentally killed and
                  groups throughout summer. Migration to coastal                harvested is probably not great enough to affect the
                  areas coincides with the break-up of ice and the              total population, but the affect on local stocks is
                  arrival of spawning fish such as Arctic cod                   unknown (800 is 5% of the minimum total popula-
                  (Boregadus saida), smelt, herring, capelin (Mallotus          tion estimate of 15,800).
                  villosus), and Pacific salmon. Belugas make use of
                  tides in pursuit of prey by ascending rivers on the           For further information
                  flood and descending with ebb tides; a few have been
                  sighted 1,000 Ian up the Yukon River.                         Braham, H. W., B. D. Krogman, and G. Carroll.
                     Calving occurs from about March to September               1984. Bowhead whale and white whale migration,
                  and peaks in mid-summer. Age at sexual maturity in            distribution, and abundance in the Bering, Chukchi
                  females is 4-7 years (based on two growth layers in           and Beaufort Seas, 1975-1978. NOAA Tech. Rep.,
                  the teeth for estimating age) and 5-8 years for males.        NUFS SSRF-778,39 p.
                  Ile calving intervals are generally every 3 years, but
                  about 25% calve every other year. Birth rate tapers           Hazard, K. 1988. Beluga whale, Delphinapterus
                  off with age from a peak of about 0.333 at age 11-22          leucas, p. 195-235. In J. Lentfer. (ed.)., Selected
                  to 0.125 at age 29-38. The average life span isabout          marine marnmals of Alaska. Species accounts with
                  30 years, but older animals up to 40 years have been          research and management recommendations. Mar.
                  found in the wild. Gestation is presumed to last 14-          Mammal Comm., 1825 Connecticut Ave NW, Room
                  15 months, although delayed implantation cannot be            512, Washington, D.C. 20009.

                  100                                                                                       Marine Mammals





                                                                            35. DALL'S PORPOISE


                        Dail's porpoise (Phocoenoides dalli) are widely         mean take rate for observed salmon gill-net opera-
                    distributed across the entire subarctic North Pacific       tions from 1981 to 1985 was OA7 porpoise per set
                    Ocean. Four color morphs of the same species have           (15 Ian of net) inside the EEZ. The estimated
                    been identified. The P. dalli truei morph, common           incidental catch outside the EEZ ranged from 479 to
                    along the Pacific coast of Japan, is black with a           1,716. These fisheries no longer operate in U.S.
                    white flank patch extending forward as far as the           waters and are not monitored by U.S. observers
                    flippers, and a white throat patch. The P. dalli dalli      outside the EEZ. -
                    morph is more cosmopolitan throughout the species'             Incidental take by the Japanese squid fishery were
                    range; the white flank patch does not extend forward        reported by the Fisheries Agency of Japan to be
                    beyond the dorsal fin, and there is no white throat         2,500 in 1982, 2,502 in 1983, and 2,515 in 1984.
                    patch. The third morph, which is uncommon, is a             The observed take in 1989 was 141 Dail's porpoise,
                    solid black form occurring along the Sanriku coast of       but this was based on monitoring only 4%-10% of
                    Japan and in the northwestern Pacific. Dail's               the fishing effort by the fleet. The impact of com-
                    porpoise occur predominantly offshore but may be            mercial fishing on Dail's porpoise is unknown.
                    inshore in some areas-, the southern extent of their
                    range is approximately lat. 28*N, which coincides           For further information
                    with the 17*-18* C isotherm. The northern limit is
                    generally Cape Navarin, U.S.S.R., in the western            Kasuya, t., and L. L. Jones. 1984. Behavior and
                    Bering Sea (lat. 62*N), although there are a few            segregation of the Dail's porpoise in the northwest-
                    recorded sightings off northwest Alaska (i.e.,              ern North Pacific Ocean. Sci. Rep. Whales Res.
                    Chukchi and Beaufort Seas). Three populations or            Inst., Tokyo 35: 107-128.
                    stocks are postulated for the western North Pacific
                    and adjacent areas: the truei morph off the Sanriku         Kasuya, T., and S. Shiraga. 1985. Growth of Dail's
                    coast as far east as long. 180*; the dall! morph            porpoise in the western North Pacific and suggested
                    between Japan and the Aleutian Islands; and the             geographic growth differentiation. Sci. Rep. Whales
                    dalli morph in the Okhotsk Sea. Stock separation            Res. Inst., Tokyo 36: 139-152.
                    has also been hypothesized for the eastern North
                    Pacific, but specific areas have not been proposed.         Winans, G., and L. L. Jones. 1988. Electrophoretic
                    The reproductive cycles of animals in the Bering Sea        variability in Dail's porpoise (Phocoenoides da1h) in
                    and western North Pacific are apparently out of             the North Pacific Ocean and Bering Sea. J. Mam-
                    phase, further supporting the stock separation              mal. 69: 14-21.
                    hypothesis.
                        Throughout most of the eastern North Pacific,
                    Dail's porpoise are present during all months of the
                    year, although there may be seasonal inshore-
                    offshore and north-south movements in Alaska, such
                    as out of Prince William Sound and areas in the Gulf
                    of Alaska and Bering Sea. Based on studies carried
                    out between 1978 and 1992, the minimum estimated
                    abundance of Dail's porpoise in the Bering Sea,
                    Aleutian Islands, and Gulf of Alaska is 417.000
                    (95% CI : 316,000-575,000) but does not include
                    Southeast Alaska.
                       The Japanese high-seas salmon mothership
                    fishery has been operating in the North Pacific since
                    1952. The estimated annual incidental take by the
                    Japanese in this fishery (1981-87) within the U.S.
                    F= ranged from 741 (1987) to 4,187 (1982). The


                    Marine Mammals                                                                                                101





                 36.HARBOR PORPOISE






                                                                        7








                   Harbor porpoise (Phocoena phocoena) in the               Alaska. A single incidental capture from the Bering
                eastern North Pacific Ocean range'from the Beaufort         Sea was reported in 1982, and I I animals were
                Sea, Alaska, to Point Conception, California,               reported taken from Bering Sea during high-seas
                although records of harbor porpoise from Los                gillnet salmon fisheries between 1978 and 1987.
                Angeles Harbor also exiSt. The smallest of the North        The only documented study of incidental take of
                Pacific porpoises, Phocoena is less than 6 ft long,         harbor porpoise is from the Copper River Delta
                dark grey on top and light-colored underneath and           where 102 Phocoena were reported entangled in
                has a proportionally large triangular dorsal fin.           1978 of which 44 were released alive.
                Female harbor porpoise reach maturity at 3 years of
                age and probably reproduce annually. Gestation              For further information
                lasts I I months. Maximum age is perhaps around
                15 years. Harbor porpoise feed on schooling fish,           Gaskin, D. E. 1983. The harbor porpoise: Regional
                such as herring and capelin, but also euphausiids           populations, status and information on direct and
                and squid.                                                  indirect catches. Rep. Int. Whaling Comm. 34: 569-
                   The total number of harbor porpoise in Alaska is         86.
                unknown. Some systematic surveys in Alaska for
                other cetaceans have frequently included harbor             Matkin, C. 0., and F. H. Fay. 1980. Marine
                porpoise sightings. A seasonal peak of over 500             marnmal-fishery interactions on the Copper River
                animals in Prince William Sound was estimated in            and in Prince William Sound, Alaska, 1978. Mar.
                the late 1970s. Densities of harbor porpoise in the         Mammal Comm. Rep., MMC-78/70. (Available
                eastern Bering Sea were estimated in the mid-1980s          through NTIS, Springfield VA, as PB 80-159536.)
                at 13 animals per 1,000 mnP. Three geographic
                stock units have been proposed for Alaska: the              Taylor, B. L., and P. K. Dawson. 1984. Seasonal
                northern Bering Sea and adjacent Arctic waters; the         changes in density and behavior of harbor porpoise
                Aleutian Islands and southern Bering Sea; and the           (Phocoena phocoena) affecting census methodology
                Gulf of Alaska and Southeast Alaska. These                  in Glacier Bay National Park, Alaska Rep. Int.
                divisions are not confirmed but are suggested based         Whaling Comm. 34:479-483.
                on oceanographic conditions and topography of the
                am which might limit the movements of harbor                Yurick, D. B. 1977. Populations, sub-populations,
                porpoise.                                                   and zoogeography of the harbor porpoise, Phocoena
                   Insufficient information is available on abun-           phocoena (L.). M. S. Thesis. University of Guelph.
                dance and incidental mortality to make an assess-           Guelph, Ontario, Canada. 148 p.
                ment of the status of harbor porpoise populations in

                102                                                                                     Marine Mammals





                                                              37, NORTHERN SEA LION

                                                                                                                                    A
                                                                                                      , wur




                                                                       V


                                                 :16_
                                                          al@ft e, A  IOU

                                        A _44w.


                                                                                         Aw-





                                                                                                                       Photo: Richard Merrick
                         The northern sea lion (Eunwtopiasjubatus), also           Alaska to the Aleutian Islands, the sea lion popula-
                      known as the Steller sea lion, is endemic to the             tion has declined from 67,617 counted in 1985 to
                      North Pacific Ocean. Its range is from the Kuril             20,679 in 1992 -- a decrease of 69% in just 7 years.
                      Islands, Russia, to California, north to lat. 630N and       The greatest decline since the 1960s has been in the
                      south to lat. 330N. Breeding units occur throughout          eastern Aleutian Islands (94% decline), the former
                      the species range, except in Washington. Sea lions           center of abundance of the species. During the
                      exhibit strong site fidelity at about 50 rookeries,          1980s, all areas of the species' range declined except
                      range-wide, and disperse after reproduction but do           in Southeast Alaska, British Columbia, and Oregon.
                      not migrate. Peak pupping is early June, and                     It is unclear why the decline has occurred or
                      lactation lasts 7 months to over I year. Sexual              whether it is related to fishery activities or from
                      maturity occurs at age 4-6 in females, while gesta-          some unknown natural environmental factor.
                      tion lasts 9 months after a 3-month delayed implan-          Northern sea lions are the most frequent marine
                      tation. The mating system is polygamous.                     mammal taken in commercial fisheries. Incidental
                         Northern sea lions feed on Pacific salmon, squid,         take in trawl fisheries in 1973-88 may have played
                      Pacific herring, groundfish (such as walleye pol-            an important role in the decline in the 1970s, but not
                      lock), and other finfish species. Walleye pollock            in the 1980s. Food availability is considered to be
                      greater thaii 25cm predominate in the sea lion's diet        one plausible hypothesis. Other factors such as
                      seasonally in Alaska. Female summer feeding trips            disease, predation, native subsistence and entangle-
                      can extend out to 20nmi: in winter the females may           ment in nets and debris are not significant in the
                      forage out to several hundred miles.                         decline. Intentional shooting may have been impor-
                         Ile abundance of sea lions was first noticed to be        tant at various times or areas.
                      declining in Alaska in 1976. Since the late 1960s the            In 1990 the northern sea lion was listed as a
                      species has declined by about 70%. From the Gulf of          threatened species under the Endangered Species


                      Marine Mammals                                                                                                    103
                           ru










                 Act. Since then, Federal action has been
                 taken to restrict certain fisheries activities          Highest Counts of Northern Sea Lions
                 near sea lion breeding sites and potential                           in U.S. Waters
                 habitat important for feeding; some of this
                 habitat extends across much of the southern      U.S.           1956-68 1975-77 1984-86 1989-92
                 Bering Sea and the Gulf of Alaska. A             -----------------------------------------------
                                                                  Alaska         150,572 129,347       89,295     34,844
                 recovery team and plan have been established     Oregon'              -     1,785     2,503       3,035
                 to assist the NUFS in managing the potential     California 2     3,100     2,600     2,500       2,000
                 conflict between conserving northern sea
                 lions and the allocation of fish in domestic
                 fisheries.                                         I Washington currently is 300-600.
                                                                   2 Rounded; some extrapolations among years.
                 For further information


                 Braham, H., R. Everitt, and D. Rugh. 1980.
                 Northern sea lion population decline in the
                 eastern Aleutian Islands. J. Vrddl. Manage.
                 44: 25-33.


                 Loughlin, T., and R. Merrick. 1989. Com-
                 parison of commercial harvest of walleye
                 pollock and northern sea lion abundance in
                 the Bering Sea and Gulf of Alaska. In
                 Proceedings of the International Symposium
                 on the Biology and Management of Walleye
                 Pollock. p. 679-700. Alaska Sea Grant Rep.
                 No. 89-1.


                 Loughlin, T.R., A.S. Perlov, and V.A.
                 Vladimirov. 1992. Range-wide survey and
                 estimation of total abundance of Steller sea
                 lions in 1989. Mar. Mammmal Sci. 8:220-
                 239.


                 Merrick, R., T. Loughlin, and D. Calkins.
                 1987. Decline in abundance of the northern
                 sea lion in Alaska, 1956-86. Fish. Bull.,
                 U.S. 85: 351-365.


















                 104                                                                             Marine Mammals





                                                         38. NORTHERN FUR SEAL




                                                                          47










                                                                                KY



















                       The northern fur seal (Callorhinus ursinus) is a         may not return to their islands of birth each year.
                    monotypic species ranging across the subarctic              Fur seals tend to concentrate along the continental
                    waters of the North Pacific Ocean from the Sea of           shelf and slope where nutrient-rich waters support a
                    Japan, Okhotsk Sea, and Bering Sea, and southward           variety of prey species. Some fur seals have been
                    along the coast of the temperate continental United         seen far at sea and are occasionally taken in high-
                    States. Breeding populations are found on Robben            seas gill-net fisheries. Ile southern extent of the
                    Island (Okhotsk Sea); several Kuril Islands (south of       migratory range in the eastern North Pacific Ocean
                    Kamchatka); on the Commander, Pribilof (St. Paul            is to about lat. 32oN (California-Mexico boundary)
                    and St. George Islands), and Bogoslof Islands (all in       and in the western North Pacific Ocean to about
                    the Bering Sea); and on San Miguel Island (southern         lat. 36*N (off Honshu Island, Japan). The northern
                    California).                                                extent of the range is in the Bering Sea.
                       Most mature fur seals are on or near their                  Older male fur seals (age 10- 15 years) from the
                    breeding islands from June to November and spend            Pribilof Islands winter farther north in the North
                    the remaining months at sea. Immature seals may or          Pacific Ocean thaii younger males and females.


                    Marine Mammals                                                                                                105






                Females and young males appear                                    Northern Fur Seal
                during their southbound migration                                  Eastern Bering Sea
                along the continental shelf from
                about IaL 570N to 46ON in late                         Pup Counts (in thousands)
                November and off California (40ON            350                                                                                          L
                to 38*N) in late December. In                300-
                January-April, major concentrations
                occur between Calffornia and British         250-                                                                                         T
                Columbia. The spring (northbound)            200-
                migration begins as early as March;
                some seals follow the continental            150 -
                                                                                                                                                          01
                shelf and then go westward through           100-
                the Gulf of Alaska and into the
                                                               50
                Bering Sea through the eastern                  0                                 01 Jill   1        1101  H
                Aleut= Island passes. Older (10-                       70 72 74    76    78          82    8'4   8'6   88    @O
                15 yew olds) males usually arrive
                first on the islands in May and are                         M St. George Island   =St. Paul island
                followed by the older females by late
                June. Younger males and females
                continue to arrive throughout summer.                       For further information
                   The estimated total number of northern fur seals
                in the North Pacific Ocean in 1983 was 1.2 million.         Fowler, C. W. 1988. A review of seal and sea lion
                The pre-exploitation level of fur seals is unknown;         entanglement in marine fishing debris. In D.L.
                the best estimate is that the Pribilof Islands popula-      Alverson and J. A- June (eds.), Proceedings of
                tion originally numbered between 2 and 3 million            Pacific Rim Fishermen's Conference on Marine
                animals prior to the 19th century. By the early             Debris, Kailua-Kona, Hawaii, 13-16 October 1987.
                1950s, the Pribilof herd was believed to be approach-       Available Nabiral Resources Consultants, 4055- 21st
                ing this level, and was probably close to the can-ling      Ave W., Seattle, WA 98199.
                capacity of the ecosystem at that time. The popula-
                tion size on the Pribilof and Bogoslof Islands in           Fowler, C. W. 1990. Density dependence in
                1988 was 982,000; this level is significantly less          northern fur seals (Callorkinus ursinus). Mar.
                (about two-thirds) than observed in the 1950s when          Mammal Sci. 6(3): 171-195.
                the population had reached its highest levels this
                century. Data collected in the 1950s, when com-             Loughlin, T. R., and I;L V. Miller. 1989. Growth of
                pared to those from the 1980s through 1990, show            the northern fur seal colony on Bogoslof Island,
                that 1) pup production on St. Paul Island is down by        Alaska Arctic 42(4): 368-372.
                about 60%; 2) territorial males with females on St.
                Paul Island are down about 63%; and 3) the rookery          Scheffer, V. B., C. H. Fiscus, and E. 1. Todd. 1994.
                area occupied on St. Paul Island in 1985 was less           History of scientific study and management of the
                than one-third the area used in 1948. The current           Alaskan fur seal (Callorhinus ursius), 1786-1964.
                rate of growth of the herd is not significantly             NOAA Tech. Rep. NMFS SSRF-780,70 p.
                different from zero, although pup production on St.
                George Island continues to decline at 6% per year.          York, A. E., and P. Kozloff. 1987. On the estima-
                   Fur seals are taken incidentally in the high-seas        tion of numbers of northern fur seal, Callorhinus
                foreign gill-net fisheries for squid and salmon. In         ursinus, pups born on St. Paul Island, 1980-1986.
                1989, 208 fur seals were taken (52 dead, 128 alive,         Fish. Bull., U.S. 85: 367-375.
                28 lost) in 1,402 observed net retrievals (about 4-
                10% of the fishing operations). They are rarely
                taken in domestic trawl and longline fisheries. Only
                1-3 fur seal were taken by trawl nets in 1990.



                106                                                                                     Marine Mammals





                                                                                39. HARBOR SEAL





                                                  -V

                                                                     N


                                                                . . . . . . . . . . . .

                                                                                -:07











                        Harbor seals (Phoca vitulina richardsi) range               Harbor seals am commonly caught incidental to
                     from southeast Alaska to the central Bering Sea (to        subsistence and commercial net fisheries; however,
                     about lat. 59*N). They primarily occur in coastal          the nature and magnitude of the incidental take is
                     waters where they haul-out on sand bars and rocky          generally unknown. Incidental take could have a
                     shores to give birth, molt, and rest. Mating gener-        significant impact considering the extent of net
                     ally takes place in early summer. Delayed blastocyst       fishing along the coast of Alaska. The number of
                     development of 1.5-3 months is normal, which               seat reported taken in foreign commercial trawl
                     usually takes place during the molt (late summer and       fisheries in the 1970s and the early 1980s was less
                     autumn). Lactation lasts from 3 to 6 weeks. Age at         than 10. Only two harbor seals were reported taken
                     first pregnancy is 3-6 years, but this varies through-     in domestic trawl fisheries in Alaska in 1990.
                     out Ainska
                        The total abundance of harbor                                     Harbor Seal
                     seals in Alaska is unknown. Studies                            Tugidak Island, Alaska
                     conducted in the 1970s and 1980s on
                     Tugidak Island (southwest of Kodiak             8Adult & Juvenile Counts (Numbers)
                     Island) indicate that the population
                     there declined 86% over a 16-year               7 -
                     period from 6@919 in 1976 to 571 in             6
                     1992. Similar trends may be
                     occurring at other area , such as               5
                     along the north side of the Alaska              4
                     Peninsula, but studies needed to
                     determine the extent of the decline             3
                     only began in 199 1. Preliminary                2
                     results of those studies indicate a
                     continuing decline in harbor porpoise           1
                     abundance in the Gulf of Alaska and             0
                     stable numbers in Bristol Bay.                  1976   1978   1980   1982    1984    1986    1988   1990    1992
                                                                                                  Year



                     Marine Mammals                                                                                                107










               Observations of nearshore salmon fisheries in the
               Cooper River Delta, Prince William Sound, and
               Unimak Pass area only began in 1989. Ile exten-
               sive net fisheries in other parts of the state have not
               been monitored.


               For further information

               Everitt, R., and H. W. Braham. 1980. Aerial survey
               of Pacific harbor seals in the southeastern Bering
               sea. Northwest Sci. 54: 281-288.

               Hoover, A. A. 1988. Harbor seal, Phoca vitulina, P
               107-157. In J.W. Lentfer (editor), Selected marine
               mammals of Alaska Species accounts with research
               and management recommendations. Mar. Mamm.
               Comm., 1825 Connecticut Ave NW., Room 512,
               Washington, D.C 20009.

               Perez, M. A., and T. R. Loughlin. 1990. Incidental
               catch of marine mammals by foreign and joint
               venture trawl vessels in the US. EEZ of the North
               Pacific, 1973-88. U.S. Dep. Commer., NOAA Tech.
               Rep., NMFS F/NWC-186,81p.

               Pitcher, K. W. 1990. Major decline in number of
               harbor seals, Phoca vitulina richardsi, on Tugidak
               Island, Gulf of Alaska. Mar. Mammal Sci. 62: 12 1 -
               134.




























               108                                                                               Marine Mammals





                                                                              40. SPOTTED SEAL



                       A










                             _4





                                                              V-4








                           Az -






                                                    VC                                                  V4@
                                                                                                                     Photo: Dav1d Rugh

                        Spotted or larga seals (Phoca largha) are distrib-       pollock concentrations.
                     uted along the continental shelf of the Beaufort,              Molting occurs during late spring. Loose groups
                     Chukchi, Bering, and Okhotsk Seas south to the              of up to 200 animals can be found associated with
                     northern Yellow Sea and western Sea of Japan.               ice remnants, although some seals also molt on land
                     Eight distinct breeding areas have been identified          on the eastern Bering Sea coast. This allows these
                     with three in the Bering Sea: 1) Bristol Bay to the         seals to take advantage of spring migrations of
                     Pribilof Islands; 2) Navarin Basin to the Gulf of           Pacific herring. Animals move northward and
                     Anadyr (Russia); and 3) eastern Kamchatka Penin-            inshore to the Alaskan and Siberian coasts as ice
                     sula (Russia), from Karaginskii Bay to Olyutorski           degrades and recedes. Lagoons, estuaries, mainland
                     Gulf and north into the northern Bering Sea.                beaches, offshore islands, and pack-ice near land are
                        Spotted seals are usually associated with the            used as haulout sites.
                     southern extent of the pack ice in winter and spring,          The current abundance of spotted seals in Alaska
                     but haulout on land in the northern part of the range       is unknown. In 1973 the Bering Sea population of
                     in summer and fall. Pupping occurs in the Bering            spotted seal was estimated to have been 200-250,000
                     Sea from late March through mid-May. Mating                 animals. This was based on opportunistic sightings
                     occurs at the time pups are weaned, about 4 to              and relative abundance with other species. Adult
                     6 weeks postpartum. During this period, adults are          recruitment is estimated to be 9%-11 %, but the
                     seen on ice floes as female-pup, male-female, or            growth rate of the population is unknown.
                     male-female-pup triads. Sub-adults and non-                    Walleye pollock, capelin, Arctic cod and herring
                     breeding animals are generally found in larger              are major prey items for spotted seals in the Bering
                     groups. In the southeastern Bering Sea, herds of            Sea. The importance of competition between these
                     spotted seals are found in close proximity to walleye       seals and fisheries cannot be assessed at this point,


                     Marine Mammals                                                                                                 109









                    however, because data on the population dynamics              Lowry, L. F., and K. J. Frost. 1981. Feeding and
                    and behavior of spotted seals are lacking. Based on           trophic relationships of phocid seals and walruses in
                    the spotted seal's diet, utilization of the Bering Sea        the eastern Bering Sea, p.813-824. In D.W. Hood
                    for feeding, foraging strategy, and population                and J. A. Calder (editors), The eastern Bering Sea
                    distribution, spotted seals are likely to interact            shelf. Oceanography and resources., Volume 2.
                    directly with both the commercial groundfish and              Juneau, All*-q, U.S. Dep. Commer., NOAA Off.
                    herring fisheries. U.S. fishery observers on foreign          Mar. Poll. Assess.,'U.S. Gov. Print. Off., Washing-
                    independent fishing vessels and joint venture mother          ton, D.C.
                    ships recorded the number of marine mammals
                    caught in ground fisheries from 1978 to the present.          Quackenbush, L. T. 1988. Spotted seal, Phoca
                    Between 1978 and 1986 at least 2 and perhaps as               largha, P. 107-124. In J.W. Lentfer. (editor),
                    many as 22 spotted seals were observed caught, and            Selected marine mammals of Alaska. Species
                    all died. Uncertainties in this estimate are due to           accounts with research and management recommen-
                    potential misidentification of seals. Twenty seals            dations. Nfar. Mamm. Comm., 1825 Connecticut
                    were caught in areas inhabited by both spotted seals          Ave NW., Room 512, Washington, D.C 20009.
                    and harbor seals but were all identified as harbor
                    seals.
                       During the 1960s and 1970s, Russian commercial
                    sealing and Alaskan Eskimo subsistence harvests
                    averaged about 4-8,000 spotted seals per year in the
                    Bering Sea, or about 3% of the juvenile and adult
                    population. However, takes for both groups have
                    apparently declined in recent years. Data are not
                    available to assess the impact of intentional taking
                    by domestic fisheries.

                    For further information


                    Braharn, H. W., J. J. Bums, G. A. Fedoseev and B.
                    D. Krogman. 1984. Habitat partitioning by ice-
                    associated seals and walruses in the Bering Sea,
                    April 1976, p. 25-47. In F. H. Fay and G. A.

                    Fedoseev (editors), Soviet-American cooperative
                    research on marine mammals, Volume 1. Pinnipeds.
                    U.S. Dep. Commer., NOAA Tech. Rep. 12.

                    Bums, J. J. 1970. Remarks on the distribution and
                    natural history of pagophilic pinnipeds in the Bering
                    and Chukchi Sea. J. Mammal. 51: 445-454.














                    110                                                                                        Marine Mammals







                                           RECENT TECHNICAL MEMORANDUMS



                       Copies of this and other NOAA Technical Memorandums are available from the
               National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22167.
               Paper copies vary in price. Microfiche copies cost $3.50.

               AFSC-



               26      LOW, L-L. (coordinator). 1993. Status of living marine resources off the Pacific coast of the United
                       States for 1993, 90 p. NTIS number pending.

               25      KINOSHITA, R. K., A. GREIG, J. D. HASTIE, and J. M. TERRY. 1993. Economic status of the
                       groundfish fisheries off Alaska, 1992, 102 p. NTIS number pending.

               24      SINCLAIR, E. H. (editor) 1993. Fur seal investigations, 1991, 142 p. NTIS No. P1394-118171.

               23      PARKS, N. B., F. R. SHAW, and R. L HENRY. 1993. Results of a 1988 trawl survey of groundfish
                       resources of the upper continental slope off Oregon, 164 p. NTIS No. PB94-118163.

               22      YANG, M-S. 1993. Food habits of the commercially important groundfishes in the Gulf of Alaska
                       in 1990, 150 p. NTIS No. PB94-112463.

               21      KINOSHITA, R. K., and J. M. TERRY. 1993. Oregon, Washington, and Alaska exports of edible
                       fishery products, 1992, 52 p. NTIS No. P1393-226652.

               20      REEVES, J. E. 1993. Use of lower minimum size limits to reduce discards in the Bristol Bay red
                       king crab (Paralithodes camtschaticus) fishery, 16 p. NTIS No. PB93-228187.

               19      SYRJALA, S. E. 1993. Species-specific stratification and the estimate of groundfish biomass in
                       the Eastern Bering Sea, 20 p. NTIS number pending.

               18      PELLA, J., M. HOFFMAN, S. HOFFMAN, M. MASUDA, S. NELSON, and L. TALLEY. 1993. Adult
                       sockeye and pink salmon tagging experiments for separating stocks in northern British Columbia
                       and southern Southeast Alaska, 1982-1985, 134 p. NTIS No. P1393-226660.

               17      SEASE, J. L., J. P. LEWIS, D. C. MCALLISTER, R. L. MERRICK, and S. M. MELLO. 1993. Aerial
                       and ship-based surveys of Steller sea lions (Eumetopias jubatus in Southeast Alaska, the Gulf of
                       Alaska, and Aleutian Islands during June and July 1992, 57 p. NTIS No. PB93-226025.

               16      FISCUS, C. F. 1993. Catalogue of cephalopods at the National Marine Mammal Laboratory, 183
                       p. NTIS No. P1393-226678.

               15      KINOSHITA, R. K., A. GREIG, L. E. QUEIROLO, and J. M. TERRY. 1993. Economic status of
                       the groundfish fisheries off Alaska, 1991, 94 p. NTIS No. P1393-197861.

               14      PEREZ, M. A., and W. B. MCALISTER. 1993. Estimates of food consumption by marine mammals
                       in the Eastern Bering Sea, 36 p. NTIS No. P1393-191195.

               13      BERGER, J. D. 1993. Comparisons between observed and reported catches of retained and
                       discarded groundfish in the Bering Sea and the Gulf of Alaska, 89 p. NTIS No. PB93-18471 1.

               12      HARRISON, R.C. 1993. Data report: 1991 bottom trawl survey of the Aleutian Islands area,144 p.
                       NTIS No. P1393-186237.











































































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