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

                                                       OP c

        NOAA Technical Memorandum

         NOS MEMD 2

        GULF OF THE FARALLONES,
    ~    NATIONAL MARINE SANCTUARY

        CURRENT RESEARCH TOPICS
        IN THE MARINE ENVIRONMENT

                                                COASTAL WIN, H
                                             INFORMATION CENTER

    O ~Washington, D.C.

       .N6
       no. 2

                  ~~QMI~IERCE  Mn~osptienc Adrmnistrati~~f~  Maniagement Division

    NOAA Technical Memorandum
    N0OS MEMD 2

    CURRENT RESEARCH TOPICS
    IN THE MARINE ENVIRONMENT

    Miles M. Croom* and Nancy Stone**, Editors

    *Sanctuary Manager, **Deputy Sanctuary Manager,
    Gulf of the Farallones National Marine Sanctuary,
     Fort Mason, Building #201, San Francisco, CA  94123

                                    U.S. DEPARTMENT OF COMMERCE NOAA
                                    COASTAL SERVICES CENTER
    Washington, D.C.                    2234 SOUTH HOBSON AVENUE
    August 1987             ~CHARLESTON, SC 29405-t24i3

    UMTED STATES            IlS OcaMIC and         NMaion Ocean Sric
    DEPARTMENT OF CGUMEACS  AugphAminislraUa     /

                                    NOAA TECHNICAL MEMORANDA

                                      National Ocean Service Series

                            Marine and Estuarine Management Division

          The National Ocean Service, through its Office of Ocean and Coastal Resource Management, conducts
    natural resource management related research in its National Marine Sanctuaries and National Estuarine Reserve
    Research System to provide data and information for natural resource managers and researchers. The National
    Ocean Service also conducts research on and monitoring of site-specific marine and estuarine resources to
    assess the impacts of human activities in its Sanctuaries and Research Reserves and provides the leadership
    and expertise at the Federal level required to identify compatible and potentially conflicting multiple uses of
    marine and estuarine resources while enhancing resource management decisionmaking policies.

          The NOAA Technical Memoranda NOS MEMD subseries facilitates rapid distribution of material that may
    be preliminary in nature and may be published in other referreed journals at a later date.

    MEMD 1  M.M. Littler, D.S. Littler and B.E. Lapointe. 1986. Baseline Studies of Herbivory and Eutrophication
              on Dominant Reef Communities of Looe Key National Marine Sanctuary.

    MEMD 2 M.M. Croom and N. Stone, Eds. 1987. Current Research Topics in the Marine Environment.

    National Marine Sanctuary Program
    Marine and Estuarine Management Division
    Office of Ocean and Coastal Resource Management
    National Ocean Service
    National Oceanic and Atmospheric Administration
    U.S. Department of Commerce

    NOTICE

    This report has been approved by the National Ocean Service of the National Oceanic and
    Atmospheric Administration (NOAA) and alpproved for publication. Such approval does not
    signify that the contents of this report necessarily represent the official position of NOAA or
    of the Government of the United States, nor does mention of trade names or commercial
    products constitute endorsement or recommendation for their use.

                                  REPORT TO
           NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
                       U.S. DEPARTMENT OF COMMERCE

              NOAA TECHNICAL MEMORANDA SERIES NOS/MEMD

                           Proceedings of a Symposium on

                       Current Topics in the Marine Environment

              A Symposium sponsored by the Gulf of the Farallones National
                Marine Sanctuary, Point Reyes National Seashore, and the
                     Environmental Action Committee of West Marin

                                  March 21, 1987

                       Miles M. Croom and Nancy Stone, Editors

                                   August 1987

    U.S. DEPARTMENT OF COMMERCE
    NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
    NATIONAL OCEAN SERVICE
    OFFICE OF OCEAN AND COASTAL RESOURCE MANAGEMENT
    MARINE AND ESTUARINE MANAGEMENT DIVISION
    WASHINGTON, D.C.

                                   REPORT TO
       NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
                     U.S. DEPARTMENT OF COMMERCE

          NOAA TECHNICAL MEMORANDA SERIES NOS/MEMD

                          Proceedings of a Symposium on
                     Current Topics in the Marine Environment

           A Symposium sponsored by the Gulf of the Farallones National
             Marine Sanctuary, Point Reyes National Seashore, and the
                  Environmental Action Committee of West Marine

                                   March 21, 1987

                    Miles M. Croom* and Nancy Stone**, Editors

    * Sanctuary Manager, ** Deputy Sanctuary Manager, Gulf of the Farallones National Marine Sanctuary:
                    Fort Mason, Building #201, San Francisco, California 94123
                                     (415) 556-3535

                    This work is the result of research sponsored by the U.S.
                   Department of Commerce, National Oceanic and Atmospheric
                    Administration, National Ocean Service, Office of Ocean and
              Coastal Resource Management, Marine and Estuarine Management Division

                                                   FORWARD

    The Gulf of the Farallones National Marine Sanctuary is pleased to present these Proceedings of the Symposium
    on Current Research Topics in the Marine Environment. The projects described here represent a sampling of
    the research sponsored by the National Oceanic and Atmospheric Administration's (NOAA) Marine and Estuarine
    Management Division in the Gulf of the Farallones region to refine our understanding of the resources within the
    Sanctuary, the natural processes that occur there, and the effect of human uses and interactions with the
    environment.

    The Sanctuary was designated in 1981 for the purpose of ensuring the long-term protection of the resources
    within the boundaries of this marine protected area. To achieve this primary management goal, the Sanctuary
    conducts programs in research, education and interpretation, and resource protection. The various programs are
    integrated in such a way that the products or results of one reinforce and enhance the others. Research is
    aimed toward identifying and examining specific Sanctuary resources. Results from research activities, for
    example, are used to improve resource protection efforts and, as in the case of this Symposium, to inform the
    public about the Sanctuary- how it "works," why it is special, and what we can do to protect and preserve its
    values.

    But the Gulf of the Farallones National Marine Sanctuary does not and cannot exist in a vacuum. Vigorous
    public support -- the kind of support that led to the designation of the Sanctuary - is essential for a vital
    Sanctuary presence that will ensure the long-term health and stability of the habitats and inhabitants that make
    the Gulf of the Farallones a place of such magnificent beauty and powerful inspiration. Wise management of
    these protected areas also depends on the best use of all the program resources that we can muster; the
    coordinated efforts of agencies like NOAA and the National Park Service are also essential for the responsible
    management of the public's resources and the protection of the public's interest.

    By these criteria, the Symposium was a demonstration of new knowledge of Sanctuary resources shared with
    the public and which will be incorporated into other program activities. Also, the Symposium was delivered in a
    forum that resulted from the cooperative efforts of the Gulf of the Farallones National Marine Sanctuary and the
    Point Reyes National Seashore. For those of you who couldn't attend, please enjoy these Proceedings. We
    feel and hope you agree after reading the Proceedings, that the Symposium was a valuable experience that left
    us all with a better understanding of the Gulf of the Farallones.

    Finally, a special word of thanks to Nancy Stone, Deputy Sanctuary Manager, and to Armando Quintero,
    Supervisory Park Ranger, for their efforts in organizing and coordinating the myriad details that resulted in a very
    worthwhile Symposium.

                                                  Miles M. Croom
                                           Lieutenant Commander, NOAA
                                                 Sanctuary Manager

                                                        v

    CONTENTS

                                                                          Page

          FORWARD                                                            v

          Humpback Whale Studies in the Gulf of the Farallones
          National Marine Sanctuary. James C. Cubbage,
          Cascadia Research.                                                 1

          Cetacean Studies in Marine Sanctuaries.
          Steven L. Swatrz, Cetacean Research Associates.                   11

          Harbor Seals and Northern Elephant Seals in
          Point Reyes. Sarah G. Allen, Point Reyes
          Bird Observatory.                                                 16

          Potential Bioaccumulation of Long-lived Radionuclides
          by Marine Organisms in the Vicinity of the Farallon
          Islands Nuclear Waste Dump Site. Thomas H. Suchanek,
          Division of Environmental Studies, University of
          California, Davis, California.                                   20

          Field Studies of the White Shark, Carcharodon carcharias,
          in the Gulf of the Farallones National Marine Sanctuary.
          A. Peter Klimley, Bodega Marine Laboratory.                       33

          Harbor Porpoise, Phocoena phocoena, in the
          Gulf of the Farallones National Marine Sanctuary.
          Isadore D. Szczepaniak, California Academy of Sciences.          37

          Cordell Bank: What We Know and What We Don't.
          Robert W. Schmieder, Cordell Bank Expeditions.                   41

          Acknowledgements                                                  47

                             Humpback Whales in the
               Gulf of the Farallones National Marine Sanctuary:
                           Report of Ongoing Research

                                James C. Cubbage
                               John Calambokidis
                              Kenneth C. Balcomb &
                              Gretchen H. Steiger

                  Cascadia Research, Olympia, Washington 98501

                                   BACKGROUND

           Humpback whales (Megaptera novaeangliae) occur throughout the
    world and generally migrate from winter breeding grounds in low
    latitudes around 20 degrees to high latitudes during summer to feed.
    Portions of the North Pacific stock summer in the Aleutian Islands,
    Prince William Sound and the Alexander Archipelago in Alaska and winter
    off southern Baja California, the Hawaiian Islands and the Ryukyu
    Islands south of Japan. From the start of commercial whaling, humpback
    whale populations in the North Pacific were reduced from an estimated
    15,000 animals to little over 1,000 animals in the 1960's (Leatherwood
    et al. 1982, Rice 1977). In recent history (late 1950's to 1962) about
    755 humpbacks were taken from within the present day Gulf of the
    Farallones National Marine Sanctuary area (Rice 1963). Though recent
    marine mammal observations started in 1968, humpbacks were first seen in
    numbers in the Sanctuary in 1977 (Ainley et al. 1978). Recent research
    (Dohl et al. 1983) has suggested a continual increase in the number of
    humpbacks found in the early 1980's in this Sanctuary.

         This abstract reviews preliminary results of research on marine
    mammals, particularly humpback whales, in the Gulf of the Farallones
    National Marine Sanctuary and Cordell Bank area. The research was
    contracted by National Oceanic and Atmospheric Administration
    Sanctuaries Program through the National Park Service to Cascadia
    Research. A complete annual report will be available.

         The primary objectives of the proposed three-year study are to: 1)
    develop a photographic catalog of humpback whales, 2) determine the
    abundance and distribution of humpback whales in the study area, and 3)
    identify seasonal movements of humpback whales and their interchange
    with wintering grounds and other summer feeding areas. Other research
    components include: incidental observations of other marine mammals,
    aerial photogrammetry, and observations of humpback whale - vessel
    interactions.

                                    METHODS

         Vessel survey effort consisted of two components: 1) dedicated
    research by Cascadia personnel using three vessels and 2) incidental
    effort during whale watch cruises conducted by Oceanic Society
    naturalists under subcontract to Cascadia. Aerial surveys were

                                                                          2

    conducted to provide a far-ranging, somewhat synoptic search for whales
    in the Sanctuary.

         The three primary vessels used by Cascadia consisted of: 1)
    Noctilio, a 44' motor sailer, 2) Shachi, a 19' Boston Whaler, and 3) a
    13' inflatable Zodiac. Both the Shachi and Noctilio were based out of
    Bodega Bay and were equipped with Loran, radar, depth sounder, and VHF
    radio. The Noctilio served as the primary base of operations logging
    330 hours of survey effort on 32 days between 23 July and 15 September
    1986. The Shachi operated on 13 days between 23 July and 2 September
    and logged 69 hours of survey effort. The Zodiac operated primarily in
    conjunction with the Noctilio, within 5nm, though on calmer days
    operated independently. The Zodiac was operated for 114 hours on 24
    days between 27 July and 15 September 1986. Tracks of all dedicated
    surveys are shown in Figure 1. The Oceanic Society whale watch cruises
    were conducted on weekends from 7 June to 26 October and originated from
    San Francisco Bay and travelled around the Farallon Islands. All
    sightings recorded by experienced marine mammal observers on board were
    examined. In the aerial survey the primary search aircraft was a
    Cessna 172 that flew for about 37 hours.

         The flukes of humpback whales show coloration and scar patterns
    that are individually unique. These patterns allow unequivocal
    identification of individual whales over several years. "Humphrey," the
    wayward humpback that wandered up the Sacramento River in 1985, was
    identified near the Farallon Islands in 1986 through these fluke
    markings. His whereabouts were unknown from November 1985 until found
    by this research in the Sanctuary. Locations of sightings of "Humphrey"
    are shown in Figure 2.

         We photographed whale flukes of most animals seen and from these
    data, not only can individual movements be determined, but an estimate
    of the population in the area can be calculated through mark-recapture
    statistics. The initial photograph of an individual serves as a mark
    and subsequent resightings can be considered recaptures using the
    Schnabel (1938) method.

         All three vessels had at least one researcher/photographer on board
    at all times, and during some photographic forays, as many as 6
    researcher/photographers were operating on three vessels simultaneously.
    Vessel survey effort was concentrated at locations where humpbacks were
    found because the primary objective for the vessels was to-,develop a
    photographic catalogue of whales.

                              PRELIMINARY RESULTS

    Humpback whales

         Distribution and Abundance  A total of 256 sightings of 707
    humpback whales were recorded during dedicated vessel surveys and 40
    sightings of 162 humpbacks were made during aerial surveys. Relative
    densities of humpback whale seen per hour of survey from the Noctilio
    are shown in Figure 3 (aerial sightings are not included). Most

                                                                           3

    animals were seen and photographed in the region between Pt. Reyes and
    Fanny Shoal north of the North Farallon Islands.

         Though a few sightings of humpbacks were made in the beginning of
    August, the major "herd" of animals was first seen on 14 August and were
    in the study area intermittently through 15 September, when major field
    effort ceased. Oceanic Society cruises conducted past the end of the
    dedicated vessel surveys indicated humpback whales remained in the study
    area through the last survey on 26 October. No calves were seen
    throughout the surveys.

         Photographs Approximately 7,000 35mm photographs were taken during
    the survey period. These photos yield at least 88 positively identified
    individual humpback whales photographed throughout the season. Obviously,
    many individuals were photographed more than once, and these resights
    form the basis of a crude estimate of numbers of animals in the study area
    in 1986 through mark-recapture statistics. The mark-recapture estimates
    show the numbers of animals in the area to number about 100. These esti-
    mates are preliminary and require additional years of sampling to confirm.

         Fluke photographs from 1986 were matched to those taken by other
    researchers (M. Webber, I. Szczepaniak, J. Stern) during previous years
    and these show that some individuals have occurred in and around the
    Sanctuary in more than one year. A catalog of 1986 photos of whales
    taken in the Sanctuary was sent to various researchers to compare fluke
    photographs to their collections of approximately 80 identified whales
    from Mexico and approximately 1600 identified whales from Hawaii.
    Mexican researchers found eight matches to humpbacks wintering in Mexico
    and none have been reported by the Hawaiian researchers, a strong
    indication of the wintering grounds of animals at the Gulf of the
    Farallones National Marine Sanctuary. However, a current hypothesis
    (Baker et al. 1986) suggests that humpbacks from several different
    summering grounds mingle on wintering grounds. The extent to which
    humpback visitors to Farallon Islands may be found on other summering
    grounds in other years is still not known.

    Blue whales

         Distribution and Abundance Ninety-four sightings of 193 blue
    whales were made during dedicated vessel surveys and 31 sightings of 52
    blue whales were made during aerial surveys. Relative densities of blue
    whales seen from the Noctilio are shown in Figure 4. Boat and aerial
    censuses indicate that at least 20-25 blue whales were in the study area
    throughout much of the study period. The high relative abundance of
    blue whales in the study area was surprising. Timing of blue whale
    occurrence in the study area closely paralleled that of humpbacks,
    though blue whales appeared to arrive in numbers a little earlier than
    the main "herd" of humpback whales.

         Photography Blue whale identification photographs offer a
    significant opportunity to determine the recurrence of individuals of
    this endangered species in the Sanctuary. These photos may also help
    determine the relationship of these animals to those photographed
    elsewhere along the California and Mexico coast.

                                                                          4

    Association of whales with water depth, birds and boats

         Depth Preliminary analysis of the survey effort and sighting data
    indicated a significant association between sighting frequency of both
    humpback and blue whales and water depth. Because different water
    depths were not sampled equally we first had to calculate the amount of
    survey effort at different depths. We restricted the analysis to data
    gathered from the Noctilio, because it provided the largest data set and
    water depths were recorded every 15 minutes during surveys. These water
    depths were used to determine the amount of time spent at different
    depths. Sightings at different depths could then be translated into
    sightings per hour of effort at that water depth (Figure 5). For both
    humpback and blue whales, sightings per hour varied significantly by
    depth (chi-square, p<O.001 for both cases). Highest sighting rates for
    both species occurred at 250-350' depth. Dall's porpoise sightings also
    varied significantly by depth (chi-square, p<0.025) with the highest
    sighting frequency in waters deeper than 450 feet. Sightings of other
    species were too limited to allow accurate statistical tests of
    sightings by.depth.

         Birds We found a significant association between humpback whales
    and mari-ne birds. We collected data on the presence of birds within
    200 m of the survey vessel during all surveys from the Noctilio and when
    whales were sighted. These data allowed us to compare the average
    number of birds encountered during surveys to those present where the
    whales were seen. Humpback whale sightings occurred at a significantly
    higher than expected rate (chi-square, p<.001) when high concentrations
    of birds were present. Blue whale sightings followed a similar pattern,
    but just failed a test of statistical significance (chi-square, p>O.05).

    Other marine mammals

         Several other marine mammal species were seen during this study.
    Cetaceans sighted included sei whale, killer whale, minke whale, Risso's
    dolphin, Dall's porpoise, harbor porpoise, and Pacific white-sided
    dolphin. Pinnipeds seen were California and northern sea lion, harbor
    seal and elephant seal.

                                   REFERENCES

    Ainley, D.G., H.R. Huber, S. Morrell, R. LeValley. 1978. Studies at
         the Farallon Islands, 1977. Final report to U.S. Marine Mammal
         Comm. Contract MM6AC027. Point Reyes Bird Observatory.

    Baker, C.S., L.M. Herman, A. Perry, W.S. Lawton, J.M. Straley, A.W.
         Wolman, G.D. Kaufman, H.E. Winn, J.D. Hall, J.M. Reinke, and J.
         Ostman. 1986. Migratory movement and population structure of
         humpback whales (Megaptera novaeangliae) in the central and eastern
         North Pacific. Mar. Ecol. Prog. Ser. 31:105-119.

    Dohl, T.P., R.C. Guess, M.L. Duman, and R.C. Helm. 1983. Cetaceans of
         central and northern California, 1980-1983: status, abundance and
         distribution. OCS Study MMS 84-0045.

    Leatherwood, S., R.R. Reeves, W.F. Perrin, and W.E. Evans. 1982.
        Whales, dolphins and porpoises off the eastern North Pacific and
        adjacent Arctic waters: A guide to their identification. NOAA
        Tech. Rept. NMFS Circ. 444. 245 pp.

    Rice, D.W. 1963. Progress report on biological studies of the larger
        cetacea in the waters off California. Norsk Hvalfangst-Tidende
        7:181-187.

    Rice, D.W. 1977. The humpback whale in the North Pacific:
        distribution, exploitation, and numbers. Prepared for Workshop on
        Humpback Whales in Hawaii, July 1977. 21 pp.

    Schnabel, Z.E. 1938. The estimation of the total fish population of a
        lake. Amer. Math. Mon. 45:348-352.

        Dom                     2  :0I                   :123: 00,              6

                    ......................  .. ....Bodega Bay .........

        37:50 1

    Figure 1. Tracklines of all dedicated vessels (Noctillo, Shachi, and
               Zodiac) throughout study period. See text for effort summary
               and vessel description.

                      :20IN:123 :40 I                 :123:20U '   8/28/86R           '123:oou

                                                            .......:I    .:.. o,

                                                                         fi
                                                                           SI

    s .. .. :O'N'''''.... .........

                                              Fgr2..."     Location of ow8/16/86

                              .o.    ..~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

       Figure

          Figure 2.   Locations of sightings of whale # 21 ("Humphrey")  in 1986.

    38:20'1  :.123:0 'u'               123:20 '0                123:00 '4                :122:40 U

                                                                                                    >5.50

                                                                                                    >4 .50

    38:10H                        I      N                                                >1.50

                                                                                                    >.50

    38*oN7:0'                   Iys

    37:501                                                                        I

    3?:qO'tl                                              /   7"

                ~~~~~~~3 I: 7s 0 ' N      ' � q/0/~~~~~~~~~~~             ~    ~~~~~~~~~ ...0.

         Figure 3.  Number of humpback whales seen per hour from Noctilio in 1986.
                      All grids have at least one hour of search.

                           'p  3~~~~~~~~"
    8:0'AD    :i42:*0 :H :123:20'J                            123  Ou'U                   .122:I0'U
                                                                                                    >1.50

                                                                                                     > 1.25

                                                                                                     >1.00
       ~~~................                             fy..                              J
    38:iO'   .                                        /                                    >0.75
                                                                                                      0.50

                                                                                                     >0.25

             3~:OK/lx /,
                  ~~~~~~~~~~~~~~~~~~~~~~~~~........

                       .8 .'  .      .               .       .     .                       .  .....i . .  . .

    3750' :4 'I    .'

                                                                            /~~~~~~~~~~

                                                        *  I..~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I
     .    .   .  .    .    .   .  .   .    .    .    .    .    .    .    .  .    .    .    .    .    .    .    .... . '..  .    .....  . .    .    .

       3:                                        ';,                           .,J' "'     :

            Figure 4.  Number of blue whales seen per hour from Noctilio in 1986.
                         All grids have at least one hour of search.

      1                                                         17j  HUMPP~AS

                                                 048 9    I-'   BLRIUE
                                       60
    0.9 -

    OZ    0.7

    0.26-

          <150       15o-        200-       250-       300         350         >400
                                   DEPTH IN FEET

    Figure 5.  Sightings of humpback and blue whales per hour of boat survey by
              depth class.  Numbers at top of bars indicate number of
              sightings in each depth class. Data from Noctilio (auxiliary
              sailer) only. The differences by depth class are significant
              (chi-square p<0.001)
                                     DET   I25 FEET

          Figure ~  ~     ~     7 5.Sgtnso7upakadbu   hlsprhu   fba   uvyb

                    Cetacean Studies in Marine Sanctuaries

                           Steven L. Swartz, Ph.D.
                      Cetacean Research Associates, Inc.
                         San Diego, California 92107

        Marine sanctuaries have traditionally concerned themselves with
    things that occur within the marine protected areas themselves, that is,
    coral reefs, resident populations of fish, archeological sites, unique
    underwater formations, and the like. More difficult to consider are the
    transitory resources that occur seasonally within a protected area and
    remain there for a period of time while they complete a portion of their
    life history. Examples include migratory populations of pelagic fish,
    birds, and marine mammals including the cetaceans -- the whales,
    dolphins and porpoises. Because transitory species pass through or
    visit marine areas for finite periods of time rather than residing within
    them permanently, they are difficult to think about, and therefore they
    pose challenging management and research tasks. Marine protected areas
    may be equally critical to the survival of both migratory and resident
    wildlife populations.

         The world's great whales are seasonal migrants that spend roughly
    half of each year migrating to the higher latitudes to feed in areas of
    high prey concentration, and the other half reproducing in tropical and
    sub-tropical waters. They continuously follow the seasonal distribution
    of their food and seasonal changes in climate. Their migrations take
    them across political boundaries and through a wide range of
    oceanographic conditions. This constant movement coupled with the fact
    they spend only brief periods at the surface makes it difficult to
    observe whales and to document their activities.

         The study of whales is further complicated by the fact that they
    are long-lived animals which respond to long-term changes in their
    habitats. It is believed that some species of great whales may live as
    long or longer than their human investigators. To acquire meaningful
    data on the needs of these kinds of animals, and to develop useful data
    bases with which to evaluate trends, observations must be conducted over
    many years. This in turn requires a long-term cormmitment on the part of
    the sponsoring agency. Often one or two seasons of research cannot
    provide the information necessary to address questions regarding the
    seasonal abundance, distribution and behavior of whale populations and
    how these may change over time. But, if well planned, they may form the
    foundation of a data base that, once established, may be added to as
    often as needed or desired.

         Once a data base of sufficient length is established, the manager
    of a marine protected area may put recent information on whale
    populations within the sanctuary into the proper perspective.  Then,
    using a trend analysis approach, appropriate management decisions may be
    made regarding whales and their use of the protected area. Although
    whale research requires extended effort and expense over prolonged
    periods, the return of useful information provided by a well planned and

                                                                           12

    properly executed long-term program is well worth the investment in terms
    of successful management of marine protected areas for the benefit of
    both the wildlife and man.

         From January 18 to February 4, 1986, the Channel Islands National
    Marine Sanctuary sponsored a pilot study with the overall goal of
    producing baseline information on gray whales (Eschrichtius robustus)
    during the peak period of their southward migration through  o--thern
    California. This was the first step toward establishing a data base for
    an ongoing program to identify long-term changes in the gray whale's use
    of this portion of their range that may result from increased levels of
    human activities.

         The specific objectives of this project were to:

         1. estimate the number and distribution of gray whales within the
             CINMS during the peak of their southward migration,

         2. determine the duration of stay of gray whales, or the rate at
             which whales migrate through the CINMS,

         3. determine their day and night travel rates through the
             Sanctuary,

         4. document inter-island migration routes, local whale movements,
             behavior, and resource use in the CINMS,

         5. opportunistically document the occurrence of other cetaceans
             within the Sanctuary, and

         6. make recommendations to appropriate wildlife management
             agencies charged with the responsibility of monitoring the
             welfare of the gray whale population and its habitat.

         The Channel Islands National Marine Sanctuary (CINMS) is a tract of
    ocean, about 1,252 nm2, encompassing the waters within 6 nm of San
    Miguel, Santa Rosa, Santa Cruz, Anacapa, and Santa Barbara Islands.
    This island system is uniquely positioned in the Southern California
    Bight, being the first islands south of Point Conception where the
    mainland coast turns east toward Santa Barbara. Two techniques, aerial
    surveys and radiotelemetry, were employed.

         Strip-surveys were flown to determine the abundance, distribution,
    behavior, and resource use of gray whales throughout the CINMS. During
    strip-surveys, two replicates were flown of a systematic grid.of north-
    south transects spaced 4 nm apart. On each replicate, requiring 6 hours
    to complete, we surveyed 265.46 nm2 of water, an estimated 25% of the
    surface area of the sanctuary. Survey 1 (on January 20 and 21) produced
    32 sightings totaling 67 whales and 8 calves, Survey 2 (on January 21,
    24 and 25) produced 23 sightings totaling 61 whales and 9 calves, and
    the average count was 64 whales and 8.5 calves. Based on these data,
    the ratio of means estimator (modified) yielded a population estimate
    (corrected for submerged whales) of 676 � SD 206 whales in the CINMS

                                                                           13

    during Survey 1, and 613 +_ SD 211 whales during Survey 2, with a mean
    estimate of 643 +_ S 173 whales (95% C.I. 683, 703). Animals clearly
    identifiable as calves of the season comprised 13.3% of all grays seen
    during strip-surveys.   The abundance of calves (uncorrected) was
    estimated at 32 +_ SD 15 for Survey 1, and 36 + SD 15 for Survey 2, with
    a mean estimate of 34 + SD 11 calves (95% C.I. 30, 38).

        A near-shore aerial survey (100% coverage) was flown on January 20
    and 24 to document the numbers, distribution, and behavior of whales
    within 0.75 nm of the sanctuary islands. Twenty-nine sightings totaling
    58 whales and 2 calves were observed; an additional 22 whales and 1 calf
    were sighted on connecting flights between the northern islands.

         Gray whales were observed throughout the CINMS, but were primarily
    distributed within waters 3 nm or less from the island shores; during
    strip transects, for example, 94 % of the mother-calf pairs and 91% of
    the whales without calves were within 3 nm of shore.  Although the mean
    distance from shore for both groups was similar (1.53 + SD 1.138 nm
    versus 1.95 + SD 1.088 im, respectively), mothers and calves were
    generally nearer to shore than were other whales; 82% of the mother-calf
    pairs were within 2 nm of shore compared to 58% of the other whales. In
    relation to water depth, 60% of the mother-calf pairs were in water
    30 fm (54.4 m) or less in depth, while the remaining 40% were in waters
    up to 300 fm (548.6 m) deep over the Santa Cruz Canyon.  The majority of
    the other whales (86%) were in waters up to 50 fm (91.4 m) deep.
    Overall, there did not appear to be a strong trend for whales to prefer
    a particular bottom type. Areas where whales tended to cluster included
    the channels between the northern islands, particularly Santa Cruz
    Channel, and points, reefs, and headlands including Point Bennett, Beacon
    Reef, West Point, and Cavern Point. Locations where few or no whales
    were seen included the south side of San Miguel Island, the southeast
    side of Santa Rosa Island, the north side of Middle and West Anacapa
    Island, and the east side of Santa Barbara Island.
         The predominant behavior of all gray whales observed during aerial
    surveys was traveling (70% of mother-calf pairs and 73% of whales
    without calves); but mothers with calves traveled more slowly than other
    whales. Overall, directional preference was southeast for whales
    without calves (64%), east-southeast for mother-calf pairs (29% E, 21%
    SE), and appeared related to the direction of the southward migration.
    Courtship and mating, seen for 42 animals, comprised 22% of the behavior
    of whales without calves. Resting and milling were seen for 25% of the
    mothers and calves, compared to 2% of the other whales. Potential
    feeding was seen for 3% of whales without calves and 5% of mother
    whales; feeding behavior was observed 5 times within kelp beds and once
    over a sand bottom. Group size varied from 1 to 14 animals, with most
    whales without calves in pairs or groups; 22% were lone animals, 19%
    were in pairs, 18% were in trios, and the remaining 41% were in groups
    of from 4 to 14 animals. In contrast, each of the mothers was alone
    with her calf. Twenty-three instances of apparent disruption to whales
    due to the activities of commercial whale-watching boats were observed.

         Radiotelemetry was used to track grays over 24-hour periods to
    determine their day and night travel rates, inter-island migration

                                                                           14

    routes, duration of stay, local movements, and behavior in the CINMS.
    Nine whales were tagged from January 21 to February I with a small (1.5
    cm by 6 cm), implantable, capsule radio-tag applied with a crossbow
    (developed by J. Goodyear). Each whale was tagged, monitored, and
    tracked from a 68-foot motor-sailer until the whale exited from the
    CINMS (6 cases), its radio signal was lost (2 cases), or it was
    abandoned by the tracking vessel (1 case); locations of whales were also
    determined using receivers aboard aircraft. Daytime and nighttime rates
    of swimming (i.e. south migration rates) were not significantly
    different.  During 29.96 hours of daylight trac--ing, the 9 whales
    traveled at a mean rate of 3.02 � SD 0.442 kts (5.59 � SD 0.819 km/hr)
    with a range from 2.11 to 3.65 kts; during 25.5 hours of nighttime
    tracking, the whales traveled at a mean rate of 3.45 � SD 0.452 kts
    (6.39 � SD 0,.837 km/hr) with a range of 2.99 to 4.19 kts. The overall
    mean duration of surfacings (i.e. the time the tag was above the water's
    surface) was 2.05 + SD 0.731 sec, ranging from 0.29 to 4.5 sec (n =
    702).  The mean length of long dives (> i min) was 3.06 � SD 2.175 min,
    ranging from 1.00 to 28.08 min (n = 829).  The minimum duration of stay
    within the CINMS varied from 3.9 to 60.7 hours  for the six whales that
    were monitored until their departure.

         In the northern portion of the CINMS, the 9 radio-tagged whales
    migrated along both the inner leeward-side (north) and the outer
    weather-side (south) of San Miguel, Santa Rosa, Santa Cruz, and Anacapa
    Islands; four inter-island routes were documented for these southward
    migrants. Finally, 6 of the 9 grays radio-tagged from January 4 to 18,
    1986, during the National Marine Mammal Laboratory sponsored study near
    Granite Canyon, California were relocated a total of 17 times within the
    CINMS. The time from the last detection of these whalers off central
    California to the first detection in the sanctuary ranged from 3 to 14
    days. Radio signals were received from these whales over I to 4 day
    periods within the CINMS.

         The occurrence of other cetaceans was documented opportunistically.
    There were 26 sightings of 4 odontocete species and 15 sightings of
    unidentified dolphin species, totaling 4,098 animals. No attempt was
    made to estimate the size of these populations.

         The gray whale is clearly an important species from the standpoint
    of public education and recreational value, aesthetic appeal, economic
    significance, and scientific interest. Because of its coastal habits,
    the gray is the only large whale that can be regularly observed from
    shore, and its lengthy annual migration is one of the world's
    outstanding wildlife spectacles. Yet, it is this affinity for coastal
    waters that poses a very real threat to the species. Concern exists
    that gray whales may be moving their migration farther and farther
    offshore in response to disturbance from increasing levels of inshore
    small boat traffic. Successful management of the CINMS with regard to
    gray whales requires an understanding of their natural history and
    ecological relationship to this habitat in which they seasonally
    concentrate. The importance of the CINMS as a habitat for these whales
    must be ascertained in order to insure that the area will remain
    available as a migratory corridor between their winter and summer

    grounds, or as an area in which to overwinter. If continued for a
    number of years, research programs like the one described here will
    contribute the background information over the long term to guide
    management decisions regarding the use of the CINMS as a habitat by gray
    whales and other cetacean species as well.

    For further information on this research program see:

    Jones, M.L. and S.L. Swartz. 1986. Radio-Telemetric Study and Aerial
         Census of Gray Whales in the Channel Islands National Marine
         Sanctuary During the Southward Migration, January 1986. Final
         Report to the National Marine Mammal Laboratory, NMFS, Seattle,
         Washington, Contract No. 50-ABNF-6-00067. 144 pp.

                   Harbor Seals and Northern Elephant Seals
                                in Point Reyes

                                 Sarah G. Allen
                          Point Reyes Bird Observatory
           4990 Shoreline Highway, Stinson Beach, California 94970

                                  HARBOR SEALS

         Harbor seals are the most prevalent of the four species of pinniped
    that inhabit the Point Reyes Peninsula. There are several primary sites
    where seals congregate on shore including Tomales Bay, Tomales Point,
    Point Reyes Headland, Drakes Estero, Double Point, Duxbury Reef and
    Bolinas Lagoon. From previous studies we have found that large numbers
    of seals congregate at these sites during the breeding season from March
    through June. Maximum counts have been around 2500 seals. During fall
    and winter months, the number of seals declines to around 1000. The
    breeding season peak represents about 20% of the estimated California
    population of harbor seals, and as a consequence the breeding population
    in Point Reyes has gained considerable attention from the agencies
    responsible for their management.

         From previous studies we also determined that diurnal and tidal
    effects on seal haul-out behavior varied within an optimum range with
    most seals hauled out from mid-day to late afternoon at low to medium
    tides, depending on the physical attributes of each location. Although
    we had gathered considerable information on these shore based habits,
    very little is known regarding the pelagic activities of this species.
    And so we embarked on a new study in 1985.

         Our main objectives were to 1) determine if the apparent decline in
    seal numbers during the winter months was due to the seals spending more
    time in the water, or if seals were moving to haul-out sites outside of
    Point Reyes, 2) if seals did move to other areas, where did they go, 3)
    did females behave differently from males, and 4) what were their daily
    activity patterns (how long did they haul-out in a day, how many days in
    a row, and how these patterns changed seasonally). To accomplish this
    range of objectives we undertook a capture and radio tagging program.

         In August of both 1985 and 1986, we captured around 20 adult seals
    over a two-day period at Drakes Estero. We chose Drakes Estero because
    it is one of the largest breeding areas in Point Reyes, and because the
    capture technique we wished to use was only possible in an estuarine
    environment. The seals were captured with a 300' eight-inceh mesh gill
    net which was set off of the haul-out site and then pulled ashore, a
    method successfully used in Oregon and Washington. Seals which were
    encircled became entangled as the net was brought to shore in a beach
    seine fashion. Seals to be tagged were removed and placed in hoop nets.
    Seals were weighed, measured, dye-marked, flipper tagged, and radio
    tagged. The transmitter was glued to the fur with 5 min epoxy, and
    would be shed when the seal molted its fur the following summer. It
    took us about 15 minutes to process each animal. Several agencies were
    involved in the capture including the California Department of Fish and

                                         -16

                                                                           17

    Game, the National Marine Fisheries Service, the Gulf of the Farallones
    National Marine Sanctuary and the Point Reyes National Seashore.

         We are using two techniques for tracking seals. We are monitoring
    their presence or absence at Drakes Estero on a 24-hour basis with a
    programmable receiver and an event recorder. To locate dispersing
    seals, we fly on a bi-weekly basis along the California coast from
    Monterey Bay to the Oregon border.

         To date, our results indicate that equal numbers of seals departed
    from Drakes Estero and stayed there through the winter months. Of the
    seals that departed, most left within one month, and there were slightly
    more females than males. Most departing seals moved to one or two other
    sites and stayed there for the entire winter rather than continuing to
    travel. Seals were highly individual in their movements and may be
    expressing a preference for location based on past experience, including
    foraging success, rather than responding to a predetermined migratory
    path or in response to changes in abundance of a single prey item.
    Locations where seals departed to included Hopkins Marine Station in
    Monterey Bay, the Klamath River near the Oregon border, the Russian
    River, Tomales Bay and Double Point. Distances traveled ranged from
    480 km to 10 kin, and females appeared to travel longer distances than
    males. In all cases seals traveled to an established seal haul-out
    site.

         From the seals that remained at Drakes Estero we have learned that
    they are strongly diurnal in their haul-out pattern in both summer and
    winter, and rarely haul-out at night. The largest percentage of seals
    were hauled out between 0400 and 1600 hr, and this represented between
    53% and 71% of the estimated number of seals in the area. Resident
    seals were hauled out on fewer days during the winter (77% of the days
    monitored) than the summer (92% of the days monitored). On average,
    seals spent seven hours per day on shore both in summer and winter.
    Though our sample size was too small to make statistical comparisons,
    two pregnant females appeared to spend more time in the water than males
    during the winter months. When seals were in the water, they either
    remained in Drakes Estero until the next low tide, or they traveled to
    nearby areas to feed such as Point Reyes Headland and Bolinas Point.

         As the breeding season rolled around again in 1986 almost all
    tagged seals returned to Drakes Estero indicating that Drakes Estero is
    a focal breeding area for seals ranging as far south as Mon~terey Bay and
    as far north as the Klamath River.

         So preliminary results indicate that the winter decline in seal
    numbers is related to both migration and a reduction in the number of
    days spent on shore. In addition, our findings suggest that Point Reyes
    may be a focal breeding area for seals of Central and Northern
    California. The protection of seals at Point Reyes, therefore, is
    important to maintaining the health of the population of this region.
    The qualities which attract seals to Point Reyes may include preferred
    substrates upon which to haul-out, bountiful food during the peak of the
    breeding season, and inaccessibility to human activities.

                                                                          18

         From this study, we hope to design a more comprehensive management
    plan for protecting seals by identifying the location and season of use
    of sensitive areas, and by devising better estimates of population
    numbers.

                           NORTHERN ELEPHANT SEALS

         The northern elephant seal is another pinniped which we are closely
    monitoring in Point Reyes since a new mainland colony was formed there
    in the past few years.  From historical reference, we know that elephant
    seals once resided in Point Reyes, but we do not know in what numbers or
    in what locations they were present.  Northern elephant seals have
    recovered from near extinction by commercial sealers in the 19th
    century, and began recolonizing former rookery sites in California in
    the 1950's.  From a mere 100 animals, the population has grown
    logarithmically to the current estimate of about 80,000.

         Individual elephant seals began arriving in Point Reyes in the
    early 1970's, but a colony did not form until 1981.  From observing
    flipper tags, we have determined that the colonizers came from Ano
    Nuevo, San Miguel Island and the Farallon Islands as these other
    colonies expanded to overflowing.  The Farallon Island colony is close
    enough for seals to travel back and forth to Point Reyes, and during the
    breeding season we have identified seals that have done so within a
    single day.

         Unlike harbor seals, elephant seals come onshore during two periods
    of the year, during the breeding season (December through March) and
    during the molt period, and currently those are the only times when they
    can be observed in Point Reyes.  However, in an established colony seals
    are present year round because each sex and age class molts at a
    different time of year.

         The current estimated population of breeding animals in Point Reyes
    is about 60 seals including 22 pups. Based on the recolonization
    process in other areas, we can expect this colony to continue to grow
    and perhaps expand into new areas in Point Reyes. If we assume a
    projected 40% increase per year, we can expect the population in Point
    Reyes to be about 250 animals in 1990. By that time, a management plan
    protecting seals from people and people from seals should be instituted.

                                   REFERENCES
    Ainley, D.Go, H.R. Huber, R.P. Henderson, and T.J. Lewis.  1977.
         Studies of marine mammals at the Farallon Islands, California 1970=
         1975. NTIS No. PB-274 046.
    Allen, S.G., D.G. Ainley, G.W. Page, and C.A. Ribic. 1985. The effect
         of disturbance on harbor seal haul out patterns at Bolinas Lagoon,
         California. Fish. Bull. 82:493-50.

    Allen, S.G., and H.R. Huber. 1983. Pinniped assessment in the Point
         Reyes/Farallon Islands National Marine Sanctuary, 1982-83. Final
         Rpt. NOAA Sanctuary Programs Office. 75 pp.

                                                                          19

    Allen, S.G., and H.R. Huber. 1984. Pinniped assessment in the Point
         Reyes/Farallon Islands National Marine Sanctuary, 1983-84. Final
        Rpt. NOAA Sanctuary Programs Office. 71 pp.

    Beach, R.J., A. Geiger, S. Jeffries, S. Treucy, and B. Troutman. 1985.
        Marine mammals and their interactions with fisheries of the
         Columbia River and adjacent waters, 1980-1982. Third Annual Rpt.
        U.S. Dept. of Comm., Nat. Marine Fish. Serv.  234 pp.

    Boulva, J. and I.A. McLaren. 1979. Biology of the harbor seal, Phoca
         vitulina, in eastern Canada.  Bull. Fish. Res. Bd., Can. 200:T-3.

    Brown, R.F. and B.R. Mate. 1983. Abundance, movements, and feeding
         habits of harbor seals, Phoca vitulina, at Netarts and Tillamook
         Bays, Oregon.  Fish. Bu1T :291-301.

    Fancher, L. 1979. The distribution, population dynamics, and behavior
         of the harbor seal, Phoca vitulina richardsi, in south San
         Francisco Bay-, California. MS Thesis. Calif. St. Univ.,
         Hayward, California. 109 pp.

    Hanan, D. 1986. California Department of Fish and Game, Coastal Marine
         Mammal Study, Annual Report for the period July 1, 1984 to June 30,
         1985.  U.S. Dept. Comm., NMFS.  Adm. Rept. LJ-86-25C.  46 pp.

    Herder, M.  1986.  Seasonal movements and haul out site fidelity of
         harbor seals, Phoca vitulina richardsi, tagged at the Klamath
         River, California.  MA Thesis, Humbo-t St. Univ., Arcata,
         California. 52 pp.

    Pitcher, K.W. and D.C. McAllister. 1981. Movements and haul out
         behavior of radio-tagged Harbor Seals, Phoca vitulina. Can. Field-
         Natur. 95:292-297.

    Stewart, B.S. 1984. Diurnal hauling patterns of harbor seals at San
         Miguel Island, California. J. Wildl. Manage. 48:1459-1461.

    Stewart, B.S., and P.K. Yochem. 1984. Radiotelemetry studies of
         hauling patterns, movements, and site fidelity of harbor seals
         (Phoca vitulina richardsi) at San Nicolas and San Miguel Islands,
         California, 1982.  Hubbs Sea-World Res. Inst. Tech. Rpt. No. 83-
         152.

             Potential Bioaccumulation of Long-lived Radionuclides
                    by Marine Organisms in the Vicinity of
                 The Farallon Islands Nuclear Waste Dump Site

                              Thomas H. Suchanek
                      Division of Environmental Studies
              University of California, Davis, California 95616

                                      and

                           Bodega Marine Laboratory
                                  P.O. Box 247
                          Bodega Bay, California 94923

                                    ABSTRACT

        An estimated 47,500 containers (mostly 55-gallon drums) of
    radioactive waste were dumped into the Farallon Islands Nuclear Waste
    Dump Site (FINWDS), a region of approximately 530 square miles, mostly
    overlapping with the Gulf of the Farallones National Marine Sanctuary.
    Previous studies conducted in the early 1970's showed that at least some
    barrels had imploded and leaked their contents into the surrounding
    environment.

         Sediment cores from the vicinity of the FINWDS may show
    concentrations of 239,240-Plutonium at levels up to 1064 times expected
    background concentrations. Cores from about 3.2 km away from the dump
    site may show concentrations up to 134 times expected background levels
    for these same radionuclides.

         Marine organisms (invertebrates and fishes) collected from the
    vicinity of FINWDS also show some elevated levels of 137-Cesium and
    239,240-Plutonium. In the 1970's organisms containing tissue loads of
    137-Cesium greater than 100 pCi/kg dry wt. were: INVERTEBRATES =
    polychaete worms, sea cucumbers; FISH = Short-spined thornyheads, Rat-
    tail, Sablefish, Deepsea Sole, Pacific Flatnose, Lanternfish, Pacific
    Hake, Deep Sea Smelt, Dover Sole. Organisms containing tissue loads of
    239,240-Plutonium greater than 100 pCi/kg dry wt were: INVERTEBRATES =
    sponge; FISH = Rat-tail, Pacific Sandab.

         Intertidal mussels from Southeast Farallon Island showed
    concentrations of 239,240-Plutonium of 3.4 + 0.14 pCi/kg (dry wt)
    compared with a mean of 1.0 + 0.68 pCi/kg for many other California
    sites pooled (n=19, range = 0.14-2.09 pCi/kg). Mean levels for 241-
    Americium were 8.91 + 0.68 pCi/kg compared with 2.68 + 2.95 pCi/kg for
    all other California sites pooled (n=17, range = 0.04-7.86 pCi/kg).

         Surface and bottom currents in the vicinity of the FINWDS are
    complex and not well understood. Some studies indicate that bottom
    currents from the dump site flow in a northerly direction, toward the
    vicinity of Cordell Banks. Other studies indicate that bottom currents
    could potentially transport radionuclides in an eastwardly direction

                                        - 20 -

                                                                           21

    from the dump site up-slope onto the shelf and into San Francisco Bay
    and San Pablo Bay.

         Ongoing studies of bottom-feeding fishes collected from the
    vicinity of the FINWDS are insufficient to adequately assess the
    potential transfer of long-lived radionuclides from sediments to
    invertebrates to commercially exploitable fishes. More in-depth studies
    with in-situ experiments are needed to properly address this complex
    issue.

                                  INTRODUCTION

         Between 1946 and 1970, at least 47,500 containers (mostly 55 gallon
    drums) of radioactive waste were dumped into a region of approximately
    530 square nautical miles, roughly southwest of Southeast Farallon
    Island and mostly within the Gulf of the Farallones National Marine
    Sanctuary (Joseph et al., 1971). In 1946 an estimated 150 containers
    were dumped at a 91 m depth site (ca. 300 ft. 50 fm) at roughly 370 37'
    N; 1230 00' W. From 1951-1953 another 3,600 containers were dumped at a
    914 m site (ca. 3,000 ft; 500 fm) at roughly 370 38' N; 1230 08' 30" W.
    Finally, from 1945-1950 and from 1954-1970 an additional 44,000
    containers were dumped at an 1829 m site (ca. 6,000 ft; 1000 fm) in the
    vicinity of 370 37' N; 1230 20' W (Joseph, 1956; Waldichuk, 1960; Joseph
    et al., 1971). Apparently, adequate inventories of the contents of these
    containers were not kept or are not available today. However, excluding
    3-H ("tritium" with a 12.2 year half-life), an estimated 14,500 Curies
    (Ci) of radioactive materials (including 30-y 137-Cesium, 432-y 241-
    Americium, 88-y 238-Plutonium, 24110-y 239-Plutonium, 6560-y 240-
    Plutonium and other anthropogenic transuranic radionuclides) were
    deposited at these sites.

                               PREVIOUS STUDIES:

         Several studies on the levels and distribution of long-lived
    radionuclides have been conducted at or near the Farallon Islands
    Nuclear Waste Dump Site (FINWDS). As early as 1974, some waste
    containers were viewed with the remotely controlled submersible CURV III
    and were shown to have imploded and leaked their contents into the
    surrounding environment (Dyer, 1976). Sediment cores taken from the
    vicinity of (ca. 3.2 km from) the 900 m dump site have been reported to
    have 137-Cesium concentrations significantly higher than expected
    "background" levels.1 In addition, sediment cores taken from the
    immediate vicinity of one of the dump sites have been reported to have
    2-25 times higher concentrations of 239,240-Plutonium than expected

         1 Expected background radiation levels are derived from estimates
    of fallout mostly from atmospheric weapons testing during the 1950's and
    1960's. At this latitude, expected background levels for 137-Cs are
    9.0-77.0 pCi/kg in surface sediments (0-5 cm depth) and 2.0-23.0 pCi/kg
    in sediments 5-10 cm depth. For 239,240-Pu these expected levels are
    4.5-18.0 pCi/kg for surface sediments and 0.5-7.0 pCi/kg for sediments
    5-10 cm depth.  (See Bowen in Dyer 1976.)

                                                                           22

    background levels (see Dyer, 1976; Schell & Sugai, 1980). However,
    reanalysis of Dyer's values for radionuclide concentrations reveals that
    cores taken from this site may actually range up to 1064 times expected
    background radiation levels. Similarly, cores taken 3.2 km from the
    specified dump site may range up to 134 times expected background
    radiation levels (see Table 1).

         Deep-sea organisms collected from the vicinity of the FINWDS have
    been shown to contain some elevated levels of short and long-lived
    radionuclides (Schell & Sugai, 1980) (Table 2). Organisms containing
    tissue loads of 137-Cesium greater than 100 pCi/kg dry wt are:
    INVERTEBRATES = polychaete worms, sea cucumbers; FISH = Short-spined
    thornyheads, Rat-tail, Sablefish, Deepsea Sole, Pacific Flatnose,
    Lanternfish, Pacific Hake, Deep Sea Smelt, Dover Sole. Organisms
    containing tissue loads of 239,240-Plutonium greater than 100 pCi/kg dry
    wt are: INVERTEBRATES = sponge; FISH = Rat-tail, Pacific Sandab. The
    significance of these radionuclide concentrations, their actual
    bioaccumulation rates and the relationship to concentrations found in
    organisms away from the dump sites is as yet unknown.

         Mussels are efficient filter feeders, and as such have been used
    effectively in statewide, nationwide and worldwide programs to monitor
    pollutant levels in the natural environment. Mussels have been found to
    concentrate radionuclides ca. 200-300 times the level found in
    surrounding seawater. The Farallon Islands have also been used as one
    of many California sites with which to compare national pollutant levels
    on both coasts of the United States through a program known As Mussel
    Watch (Goldberg et al., 1978). However, no "regular" transuranic
    radionuclide analyses have been performed on mussels during the
    California Mussel Watch program reported by Ladd et al. (1983). This is
    surprising since one set of data from the EPA National Mussel Watch
    program clearly indicates that mussel tissues from the Farallon Islands
    site (collected in 1976) yielded the highest levels of 239,2340-
    Plutonium and the highest levels of 241-Americium of any samples
    collected from both coasts of the United States (Goldberg et al., 1978).

         The EPA reported that mussel tissues from the FINWDS contained
    roughly 3.3 times the mean radionuclide concentration found at all other
    California sites pooled. Mussel samples from FINWDS have mean dry
    weight radionuclide concentration levels for 239,240-Plutonium of 3.4 +
    0.14 pCi/kg compared with a mean of 1.0 + 0.68 pCi/kg for all other
    California sites pooled (n=19, range = 0.14-2.09 pCi/kg). Mean levels
    for 241-Americium were 8.91 + 0.68 pCi/kg compared with 2.68 + 2.95
    pCi/kg for all other California sites pooled (n=17, range = 0.04-7.86
    pCi/kg). No radionuclide analyses were performed on any specific organs
    or the shells of mussels from the Farallon Islands site.

         Both surface and bottom currents have also been studied in the
    FINWDS region (Conomos et al., 1971; Conomos, 1975; D. Lindberg, pers.
    comm., unpublished data; Dyer, 1976; Conomos & Peterson, 1977). These
    results indicate that surface currents from FINWDS generally show
    significant northward and/or southward movement along the coast, whereas
    bottom currents are more complex (Fig. 2). One current meter placed on
    the bottom at the 1829 m Farallon Islands dump site during 1975 showed

                                                                           23

    essentially northward bottom current movement at speeds of ca. 1.17
    km/day (Dyer, 1976). Bottom currents moving in this direction would
    likely transport particles toward the vicinity of Cordell Banks, a
    region known to be used extensively for commercial and sport fisheries.
    However, another bottom current study (using seabed drifters released in
    the Gulf of the Farallons) indicates consistent eastward movement of
    bottom currents at speeds of at least 0.5 km/day (Conomos et al., 1970,
    1971; McCulloch et al., 1970; Conomos & Peterson, 1977). Significantly,
    these currents move particles along the sea floor up-slope from deep
    water, traveling onto the shelf with final destinations in San Francisco
    Bay and San Pablo Bay (Fig. 2).

                                ONGOING STUDIES

         Four taxa of bottom-feeding fishes and one taxon of mussels are
    currently being collected from the FINWDS and from a comparison site to
    the north to be analyzed for concentrations of long-lived radionuclides
    under a contract through the State of California Department of Health
    Services (Suchanek & Lagunas-Solar, 1986). Included in these
    collections are: four species of fishes (Dover Sole = Microstomus
    pacificus, Sable fish = Anoplopoma fimbria, Short-spined Thornyhead =
    Sebastolobus alascanus and Long-spined Thornyhead = Sebastolobus
    altiveles) and one species of mussel (Mytilus californianus).  These
    species are being collected from the FTINWDS at three sampling periods
    during 1986-1987. In addition, samples of these same species are being
    collected for control (comparison) purposes during the same periods from
    comparable depths off Point Arena (ca. 100 km north of the FINWDS).

         Most of the bottom-feeding fishes being studied are quite mobile.

         DOVER SOLE (Microstomus pacificus): Dover Sole generally occurs on
    muddy bottoms and ranges from ca. 180-3900 ft depth.  Its larvae have
    been found offshore to 280 miles.  It is not a widely migrating species,
    but has some coastwise movement, and several isolated sub-populations
    are believed to exist (Frey, 1971).  Dover Sole does, however, undergo
    extensive onshore-offshore seasonal movements related to its spawning
    cycle.  During spring through summer it can generally be found more
    inshore where it feeds extensively. During fall and winter (November-
    March) it moves offshore for spawning, where it produces buoyant
    planktonic eggs. Adults feed exclusively on benthic invertebrates:
    bivalves, scaphopods, sipunculids, polychaetes, chinoids, ophiuroids,
    gastropods and crustaceans (Frey, 1971).

         THORNYHEADS (also called Idiots or Channel Rockfish - Shortspine =
    Sebastolobus alascanus; Longspine = Sebastolobus altiveles): These
    species are non-migratory deep-water species that are generally known to
    range from 1800-2520 ft depth although they likely occur deeper
    (Phillips, 1957; Frey, 1971).

         SABLEFISH (Anoplopoma fimbria): This species prefers soft bottom
    habitats like the Dover Sole and are usually found deeper than 300 ft.
    They are not known to migrate for spawning, but migration may be
    important, as one individual tagged in Japan was later found in the
    United States (Frey, 1971). Spawning generally occurs from December-

                                                                           24

    April with a peak in January-February. Juveniles are known to feed on
    the following benthic invertebrates: copepods, amphipods, euphausids,
    fish eggs, fish larvae and the larvacean Oikopleura. Subadults and
    adults generally are believed to feed on euphausids, tunicates and fish
    (especially anchovy) (Frey, 1971; Cailliet et al., 1987).

         Although these fish species may be caught at the FINWDS, there is
    no knowledge of their past history or amount of time spent in the
    vicinity of the dump sites feeding on benthic invertebrates. Therefore,
    "negative" data (i.e., no or low radionuclide concentrations in these
    species) would not necessarily indicate that fish are not a vector for
    radionuclides entering the human food chain. What is needed is a more
    complete and in-depth analysis of the potential pathways by which these
    radionuclides may be concentrated in human food resources.

         As extremely efficient filter-feeders, mussels are being used as an
    effective radionuclide monitoring device. Higher absolute
    concentrations of radionuclides should increase the precision for the
    determination of differences between levels found at the FINWDS and
    those at the Point Arena control site.

                              RECOMMENDED STUDIES

         Because many marine organisms (taken either commercially or by
    sport fishermen) from the region surrounding the Farallon Islands are
    used as food, it is especially important to determine the nature and
    extent of any bioaccumulation of long-lived radionuclides which may have
    taken place in these organisms. In addition, it is important to
    evaluate to what extent, if any, this source of radionuclides may be
    affecting other marine life or the natural environment in the local
    region.

         One species of fish that is currently used only for pet food or
    fish meal and that has been considered a "trash fish" for some time is
    the Pacific Hake (Merluccius productus) (Alverson & Larkins, 1969). It
    is expected, however, that this species will be exploited for human
    consumption in the relatively near future. Pacific Hake populations
    undergo long seasonal feeding migrations. They migrate from winter
    spawning grounds in Southern California to several locations along the
    West Coast from Central California to British Columbia (including the
    Farallon Islands) to feed during summer months. It is not known whether
    discreet sub-populations exist, or whether panmixia occurs in the
    spawning grounds. However, during summer feeding in the Farallon
    Islands region, this species also has the potential to accumulate
    radionuclides from the FINWDS. Therefore, the importance of analyzing
    both local and widely migratory fish species should not be overlooked.

         Bioturbation, the process of sediment disturbance by organisms
    feeding upon or moving through sediments, has also been documented in
    the region of the FINWDS (Dyer, 1976; Reish, 1978; Dayal, 1979; Schell &
    Sugai, 1980). In most areas of the shallow and deep-sea, some of the
    most important bioturbators are sediment-dwelling worms and crustaceans
    (Toots, 1961; Suchanek, 1983; Suchanek & Colin, 1986; Suchanek et al.,
    1986). Many of these organisms (especially the crustaceans) burrow

                                                                           25

    deeply into the sediment (often 1-2 m) and may contribute to the
    mobilization or remobilization of materials (both physical and
    biological) both down into the sediment and/or up from depths within the
    sediment (Clifton & Hunter, 1973; Ott et al., 1976; Pemberton et al.,
    1976; Suchanek, 1985).

         In regions where radionuclides are found associated with or
    incorporated into sediments, bioturbators are likely to influence the
    vertical distribution of the radioactive particles, either through
    burial or through remobilization of particles back to the sediment/water
    interface or into the water column (Bowen et al., 1976; McMurtry et al.,
    1985, 1986; Colin et al., 1986; Suchanek & Colin, 1986; Suchanek et al.,
    1986). This process can facilitate the consumption of radionuclide-rich
    sediments by deposit-feeding invertebrates which, in turn, may be
    consumed and further concentrated by commercially exploited bottom-
    feeding fishes. Near the Farallon Islands Nuclear Waste Dump Site, this
    concern is especially relevant for such bottom-feeding fishes as the
    Dover Sole, the Short-spine and Long-spine Thornyheads and the
    Sablefish, all of which are consumed by humans. Therefore, in-situ
    bioturbation studies would yield valuable data on mixing rates of
    sediments in the vicinity of the barrels and allow estimation of
    radionuclide transfer rates from the sediment surface to depth and of
    remobilization of radionuclides from regions deep within sediments back
    to the surface.

         Even if the radionuclide levels determined for sediments and
    organisms in the early 1970's were within acceptable and/or expected
    background levels, the intervening 15+ years has further acted upon the
    16-gauge steel 55-gallon drums. In 1987, some 30-40 years after many of
    these barrels were deposited, an unknown amount of deterioration of
    barrels has taken place. A more in-depth study should now be initiated
    in which the processes and pathways of any potential bioaccumulation of
    long-lived radionuclides is evaluated for this site.

         These studies should include at the minimum:

         1. Gross determination of radionuclide concentrations found both
             at the dump site and at a control (comparison) site including
             concurrent sampling of:

             a) Sediments
             b) Water Column
             c) Invertebrates
             d) Fishes

         2.  Modeling of radionuclide concentrations and transfer  rates
             between the physical (sediment and water) components and
             biological components of the deep-sea community found at the
             FINWDS.

         3. Rigorous oceanographic current studies (both surface and bottom
             currents) to determine more accurately the pathways along which
             radionuclide particles from the FINWDS may pass. Data

                                                                          26

            available from currently published literature conflict
            significantly (see above).

        4. Initiation of in-situ bioturbation studies to determine to what
            extent and to what sediment depth radionuclides are being mixed
            and potentially remobilized into the water column.

        5. Expansion of present biological studies to include Pacific Hake
            populations.

                               LITERATURE CITED

    Alverson, D.L. & H.A. Larkins. 1969. Status of knowledge of the
         Pacific Hake resource. California Marine Resource Commission,
        CalCOFI Report 13:24-31.

    Bowen, V.T., H.D. Livingston & J.C. Burke. 1976. Distribution of
         transuranius nuclides in sediment and biota of the North Atlantic
         Ocean. pp. 107-120. In: Transuranium Nuclides in the
         Environment. Proceedings of a Symposium - IAEA - Vienna. IAEA-SM-
         199/96.

    Cailliet, G.M., E.K. Osada & M. Moser. 1987. Ecological studies of
         Sablefish in Monterey Bay. California Fish and Game Bulletin (in
         press).

    Clifton, H.E. & R.E. Hunter. 1973. Bioturbational rates and effects in
         carbonate sand, St. John, U.S. Virgin Islands. Journal of Geology
        81: 253-268.

    Colin, P.L., T.H. Suchanek & G.M. McMurtry. 1986. Water pumping and
         particulate resuspension by callianassids (Crustacea;
         Thalassinidea) at Enewetak and Bikini Atolls, Marshall Islands.
         Bulletin of Marine Science 38:19-24.

    Conomos, T.J. 1975. Movement of spilled oil as predicted by estuarine
         nontidal drift. Limnology & Oceanography 20:159-173.

    Conomos, T.J. & D.H. Peterson. 1977. Suspended-particle transport and
         circulation in San Francisco Bay. In: Estuarine Processes II.
         Circulation, Sediments, and Transfer of material in the Estuary.
         Academic Press, New York.

    Conomos, T.J., D.H. Peterson, P.R. Carlson & D.S. McCulloch. 1970.
         Movement of seabed drifters in the San Francisco Bay estuary and
         the adjacent Pacific Ocean. U.S. Geological Survey Circular 637-B.
         7 pp.

    Conomos, T.J., D.S. McCulloch, D.H. Peterson & P.R. Carlson. 1971.
         Drift of surface and near-bottom waters of the San Francisco Bay
         system, California: March 1970 through April 1971. U.S.
         Geological Survey - Open File Map and USGS-HUD Basic Data
         Contribution 22.

                                                                          27

    Dayal, R., I.W. Duesdall, M. Fuhrmann & M.G. Heaton. 1979. Sediment
        and water column properties at the Farallon Islands radioactive
        waste dumpsites. Marine Sciences Research Center, State
        University of New York, Stony Brook.

    Dyer, R.S. 1976. Environmental surveys of two deep-sea radioactive
        waste disposal sites using submersibles. In: International
        Symposium on the Management of Radioactive Wastes from the Nuclear
         Fuel Cycle. IAEA-SU-207/65 (IAEA - Vienna, 1976).

    Frey, H.W. (Ed.). 1971. California's Living Resources and Their
         Utilization. Department of Fish and Game. 148 pp.

    Goldberg, E.D., V.T. Bowen, J.W. Farrington, G. Harvey, J.H. Martin,
         P.L. Parker, R.W. Risebrough, W. Robertson, E. Schneider & E.
         Gambel. 1978. The Mussel Watch. Environmental Conservation
         5:101-125.

    Joseph, A.B. 1956. United States Sea Disposal Operations - A summary
         to December 1956. Mimeo report Washington - 734.

    Joseph, A.B., P.R. Gustafson, I.R. Russell, E.A. Schuert, H.L. Volchok &
         A. Tamplin. 1971. Sources of radioactivity and their
         characteristics. In: Radioactivity in the Marine Environment.
         Washington, D.C.: NAS) pp. 6-41.

    Ladd, J.M., S.P. Hayes, M. Martin, M.D. Stephenson, S.L. Coale,
         J. Linfield & M. Brown. 1984. Trace metals and synthetic organic
         compounds in mussels from California's coast, bays and estuaries.
         California State Mussel Watch: 1981-1983 Biennial Report. Water
         Quality Monitoring Report no. 83-6TS.

    McCulloch, D.S., D.H. Peterson, P.R. Carlson & T.J. Conomos. 1970.
         Some effects of fresh-water inflow on the flushing of South San
         Francisco Bay: a preliminary report. U.S. Geological Survey
         Circular 637-A. 27 pp.

    McMurtry, G.M., R.C. Schneider, P.L. Colin, R.W. Buddemeir & T.H.
         Suchanek. 1985. Redistribution of fallout radionuclides in
         Enewetak lagoon sediments by bioturbation. Nature 313:674-677.

    McMurtry, G.M., R.C. Schneider, P.L. Colin, R.W. Buddemeir &.T.H.
         Suchanek. 1986. Vertical distribution of fallout radionuclides in
         Enewetak lagoon sediments: effects of burial and bioturbation on
         the radionuclide inventory. Bulletin of Marine Science 38:35-55.

    Ott, J.A., B. Fuchs, R. Fuchs & A. Malasek. 1976. Observations on the
         biology of Callianassa stebbingi Borrodaille and Upogebia litoralis
         Risso and their effect upon the sediment.  Senckenbergiana Maritima
         8:61-79.

    Pemberton, G.S., M.J. Rish & D.E. Buckley. 1976. Supershrimp: deep
         bioturbation in the Strait of Canso, Nova Scotia. Science 192:790-
         791.

                                                                          28

    Phillips, J.oB. 1957. A review of the rockfishes of California.
        California Department of Fish and Game Bulletin No. 104. 158 pp.

    Reish, D.J. 1978. Survey of the marine benthic infauna collected from
        the United States radioactive waste disposal sites off the Farallon
         Islands, California. (Unpublished report.)

    Schell, W.R. & S. Sugai. 1980. Radionuclides in the U.S. radioactive
        waste disposal site near the Farallon Islands. Health Physics
        39:475-496.

    Suchanek, T.H. 1983. Control of seagrass communities and sediment
         distribution by Callianassa (Crustacea, Thalissinidea)
         bioturbation. Journal of Marine Research 41:281-298.

    Suchanek, T.H. 1985. Thalissinid shrimp burrows: ecological
         significance of species-specific architecture. Proc: Fifth
         International Coral Reef Congress, Papeete, Tahiti 5:205-210.

    Suchanek, T.H. & P.L. Colin. 1986. Rates and effects of bioturbation on
         invertebrates and fishes at Enewetak and Bikini Atolls. Bulletin
         of Marine Science 38:25-34.

    Suchanek, T.H., P.L. Colin, G.M. McMurtry & C.S. Suchanek. 1986.
         Bioturbation and redistribution of sediment radionuclides in
         Enewetak Atoll lagoon by callianassid shrimp: biological aspects.
         Bulletin of Marine Science 38:144-154.

    Suchanek, T.H. & M.C. Lagunas-Solar. 1986. Bioaccumulation of long-
         lived radionuclides by marine organisms from the Farallon Islands
         Nuclear Waste Dump Site. Sate of California Department of Health
         Services: Interagency Agreement.

    Toots, H. 1961. Burrowing organisms and their effects on sediments.
         Geol. Soc. of America Special Paper 68:1-107.

    Waldichuk, M. 1960. Containment of radioactive waste for sea disposal
         and fisheries off the Canadian Pacific coast. In: Proc. IAEA
         Symposium, Disposal of Radioactive Wastes (IAEA, Vienna, 1960)
         Volume 2:57-77.

                                FIGURE CAPTIONS

    Figure 1.  Results of (A) surface current and (B) bottom current studies
               in the Gulf of the Farallons in 1970 and 1971. Figures
               reproduced from Conomos et al., 1971.

    Figure 2.  Migratory route of the Pacific Hake (Merluccius productus)
               along the West Coast showing winter spawning grounds in
               Southern California and summer feeding grounds in the
               vicinity of the Farallon Islands. Figure reproduced from
               Alverson & Larkins (1969).

                                                                                                                               29

    TABLE 1. Recalculation of values for 230,240-Plutonias (given in pCilkg dry wt) fromee Dyer (1976: Table 2) showing relative
              magnitudes above expected background concentrations. Results given for data from three independent laboratories.

                           (A)a                   ()b                     (C)
             Sediment  'Values from   nagnitude  Values from  Hagnitude  Values froee   agnitude
             Depth in   EPA Lab         Above      LFE Lab      Above       WHOI Lab     Above
             Core ice)  (pCi/kg)     Background  (pCi/kq)    Background  fpCil/kg)    Background

    CORES TAKEN
    FROM DUhPSITE:
    (code number)

     CORE 1   0-5       26 +1- 3         1-6       23 +1- 3       1-5        46 +I- 4      3-10
    (134273)

     CORE 2
    (1342741   0-5     360 +1- 14       20-60     447 +1- 13    25-99       482 +/- 48   27-107

               5-10        -                                      -         532 +1- 77   76-1064

     CORE 3    0-10     66 +- 17        4-132      55 +- 4       3-10            -           -
    (134271)

     CORE 4    0-10     91 +1- 20       5-182      50 +1- 5       3-100
    (134272)

    CORES TAKEN
    3.2 KR
    Southeast of
    Duepsite:

     CORE 5    0-5      67 +/- 14       4-134          -                      0 +/- 9       4-1B
    (134270)
               5-10         -                          -           -         62 +/- 4      9-124

              10-15         ?                  ? ?                 ?         15 +1- 4        ??

     CORE 6    0-10     29 +I- 12       2-58        0 +1- 4    background         -
    1134269)

    (A)a  Environmental Protection Agency: Environmental Monitoring and Support Laboratory

    (B) : LFE Environmental Analysis Laboratories

    (C)C: Mood Hole Oceanographic Institution

                                                                                         30

    TABLE 2. Invertebrates and fishes from the Farallon Islands Nuclear Waste Dump
              Site containing radionuclide concentrations (for 137-Cesium and
              239,240-Plutonium) greater than 100 pCi/kg dry wt. Data extracted
              from Schell & Sugai (1980:Table 2).

         Taxa                  Tissue              137-Cesium       239,240-Plutonium

    INVERTEBRATES:

    Polychaete worm       Evicerated whole         131 +/- 113         46 +/-  8

    Sea cucumber              Viscera              199 +/-  55         84 +/- 21

    Sponge                    Entire                   N.D.           362 +/- 38

    FISHES:

    Deep-sea Smelt           Entire                351 +/- 222          < 26

    Deep-sea Sole             Skin                 128 +/   11            -

    Dover Sale               Liver                 361 +/- 293         20 +/- 1

    Lanternfish              Entire                233 +/- 158          < 11

    Midshipman                Skin                 155 +/- 113          < 7

    Pacific Flatnose       Liver (solids)          161 +/- 105           ( 7

    Pacific Hake (juvenile) Entire                 451 +/- 432          < 41

    Pacific Sandab            Skin                     N.D.           482 +/- 95

    Rat-tail               S.I.T. contents         310 +/- 279         40 +/- 10
    Rat-tail                  Liver                    N.D.           142 +/- 23

    Sablefish                Viscera               113 +/-  91           < 3

    Short-spine Thornyhead  Skin                   278 +/- 213 < 16

    FIGU RE 1
                                                                        Aa\N1  \  w       31
                     A

                                                         *mm-

                                                                     SAN JOSE

                     FIGURE 8
                     SURFACE DRIFT
                     RELEASES; 2-6 MARCH 1971
                     RECOVERIES THROUGH 25 APRIL 1971

                                      121-                             122-

                     13?
                                             W\\_z  CRYES

                       FIGURE I
                       BOTTOM DRIFT
                       RELEASES: 5-6 MARCH 1970  2o 0\
                       RECOVERIES THROUGH 10 MAY 1970  jEr

          Figure 1.  Results of (A) surface current and (B) bottom current studies
                      in the Gulf of the Farallons in 1970 and 1971. Figures
                      reproduced from Conomos et al., 1971.

                                                                             32

       FIGURE 2

                         WINTER�
                                         ,at,~ Sa

    Figure 20 Migratory route of the Pacific Hake (Merluccius productus)
              along the West Coast showing winter spawning grounos in
              Southern California and summer feeding grounds in the
              vicinity of the Farallon Islands. Figure reproduced from
              Alverson & Larkins {1969).
              Al verson & Larki ns ( 1969) .

                       Field studies of the white shark,
                        Carcharodon carcharias, in the
               Gulf of the Farallones National Marine Sanctuary

                               A. Peter Klimley
           Assistant Research Behaviorist, Bodega Marine Laboratory
      University of California, P.O. Box 247, Bodega Bay, California 94923

         From 1985 to 1987 I have conducted field studies of the white shark
    in the Gulf of the Farallones with support from NOAA. My first
    objectives were: 1) to establish a study site where white sharks were
    relatively abundant, and 2) develop a method for affixing ultrasonic
    pingers and transmitters to the sharks. Field work was carried out May
    and September-December 1985. The latter time period was chosen because
    white shark predatory attacks on seals and sea lions are most commonly
    witnessed at Southeastern Farallon Island by field biologists of the
    Point Reyes Bird Observatory at that time. During May we made six one-
    day cruises, and during September and October we made four three-day
    cruises aboard the R/V Susan K of the Bodega Marine Laboratory to sites
    within the Sanctuary. The order in which sites were visited was based
    on evidence for the presence of white sharks (i.e., a high frequency of
    white shark captures, attacks on humans, and attacks on pinnipeds) and
    the convenience of working at each location (i.e., closeness of port,
    protection from rough seas, and absence of divers). We firstly visited
    Bird Rock, secondly Southeastern Farallon Island on two occasions, and
    thirdly Elephant Rock and Drake's Estero. During these cruises we
    baited continuously, standing four-hour watches, for time periods
    averaging 40 hours.

         During these cruises we only attracted one shark, and that was at
    Southeastern Farallon Island. The shark was not attracted to the R/V
    Susan K moored at East Landing, but a hang-bait station deployed in
    Mirounga Bay. The station consisted of an anchor, chain and line
    leading to a surface buoy and back down along the first line where a
    breakaway connection held the lines together in a midwater position. A
    buoy and radio pinger were attached to the doubled back line at this
    point. Also attached to the line was a burlap bag of fish, a plastic
    container of blood, a similar container of betaine and glycine (two
    amino acids which evoke feeding responses in sharks), and a sheep with
    an attached ultrasonic telemetry transmitter with a temperature sensor.
    If the shark were to swallow the bait and transmitter, it would monitor
    with its thermistor ingestion of warm-bodied seals or sea lions. We
    were alerted that a shark had fed on the bait by the signal of the
    surfacing radio pinger. Upon our arriving at the bait station, we
    observed that the sheep had been removed from the station. A
    Carcharodon appeared soon, feeding firstly on the burlap bag of fishes
    and secondly on the container of blood. We received a very weak signal
    on the DuKane. We assumed the signal was attenuated due to sound
    reflection from the fatty layer of ingested seals or sea lions. A
    second transponding tag will be attached externally to the shark at the
    time of internal tag implantation to increase the signal's range.

                                        - 33 -

                                                                           34

         It is difficult to believe that white sharks were not encountering
    the long corridors of olfactory stimulants created during our lengthy
    baiting sessions. I speculated whether the sharks might be avoiding the
    vessel after swimming up the corridor. Our failure to attract a white
    shark to the vessel but our success in attracting a shark to the remote
    bait station led me to hypothesize that the shark's motivation to
    approach the vessel, orienting to the odor corridor, sound playback, and
    baits, might be opposed by the motivation to withdraw. This conflicting
    motivation could be based on: 1) the vessel's large size, 2) the high
    amplitude, low frequency sounds from the waves splashing against the hull
    and continuously operating generator, and 2) the large array of lights.
    The motivation to withdraw might overcome that of approach. I decided
    that future search activities should be concentrated at Southeastern
    Farallon Island, the site providing the greatest success until this
    time, and performed from our outboard skiff. The outboard skiff was
    only the size of the largest conspecific, and for this reason, would not
    frighten sharks from feeding on a bait.

         The logistics to conducting research activities from Southeastern
    Farallon Island were formidable. Although lodging and meals were
    available at the Point Reyes Bird Observatory field station, we had to
    ship large amounts of bait to the island weekly and keep it frozen until
    use. Furthermore, we needed to be constantly vigilant of inclement
    weather. Originally, we were not allowed to lift our skiff onto our
    cradle kept on East landing because the field biologists feared the
    crane cable might break. For this reason, we motored in an inflatable
    out to our skiff tethered to the mooring in Fisherman' s Bay. The
    inflatable was attacked and sunk by a white shark while we worked
    elsewhere in Mirounga Bay. We then lifted our research skiff into the
    water with the crane before loading supplies.  This was hazardous due to
    the swell, surging back and forth within Garbage Gulch.

         Several search strategies were used at Southeastern Farallon
    Island. We repeatedly baited at a single location to habituate the
    white sharks to the presence of the skiff near a bait with an attached
    transmitter. From a record of the locations, dates, and time of day of
    white shark attacks on pinnipeds transcribed from the Point Reyes Bird
    Observatory field journals, we noticed that sharks appeared to feed in
    bouts separated by one to two days at a single location. One such bout
    had occurred on 15 and 16 October east of Saddle Rock less than a week
    prior to our arrival at the island.

         We encountered sharks every time we baited out of the Small skiff
    at Southeastern Farallon Island: almost always if we baited longer than
    two hours. A chronological record of our baiting periods as well as a
    chart with the positions of attracted sharks is given in rig. 1. In
    their first appearances, the sharks remained by the boat only briefly,
    passing under its hull two to three times before departing without
    feeding on the bait.  This may be a predatory strategy of the sharks to
    minimize the time at the surface in prey investigation, capture, and
    handling to minimize the opportunity of surface positioned pinnipeds
    from learning the shark's role as a predator. At this time I was unable
    to attach an external transmitter with a long pole spear.

                                                                          35

        The sharks later began to feed near the skiff, firstly on a burlap
    bag of fish and secondly on the sheep, although the sheep was only
    mouthed. This careful inspection and reluctance to feed is contrary to
    the shark's highly publicized image of an indiscriminate predator. To
    increase the positive reinforcement for sharks to approach the bait, we
    deployed bait stations at our baiting site. Eventually, sharks commenced
    to mouth the bait more than a single time. We could then lure them to
    the side of the skiff by retrieving the tethered bait.

         We attached an 18-month position-indicating beacon to Delta, a
    4.25 m female white shark, from the end of a pole spear after luring her
    by the side of the skiff on 14 November. Tag attachment caused little
    apparent trauma to her as she continued to swim at the same rate after
    tag attachment. She did, however, move away from the island after
    mouthing the bait several times. Her departure may have been caused by
    aggressive exclusion by Beta, a 5.25 m male, who appeared immediately
    after she left, swimming up out of the water and grasping the bait in
    his mouth before releasing it. This shark also moved away as a third
    shark surfaced, a massive individual near 6 m in length (based on tape
    marks separated by 20 cm along the chine of the skiff). This shark also
    swam up out of the water, grasped the bait, and then spit it out. The
    appearance of these three sharks on 14 November corroborated our
    estimate of the number of white sharks currently in Mirounga Bay, based
    on: 1) our encounter with Delta, a small individual in the western bay,
    2) the observation of Gamma, the largest shark, to kill a pinniped in
    the center of the bay, and 3) repeated baiting encounters and the
    observations of three pinniped kills east of Saddle Rock by Beta, an
    intermediate-sized shark (see times and locations of sightings in
    Fig. 1.) Epsilon, a fourth shark even smaller than Delta, was
    encountered west of Indian Head on 19 November.

         We were not able to track Delta as she swam away from the island
    because the seas were increasing and night was approaching. However,
    based on this tagging, we have formulated a plan of how to successfully
    tag and track sharks in the future. The RIV Susan K will tow the
    smaller skiff to the island. The larger vessel will be moored then at
    East Landing while we bait for sharks from the small skiff within
    Mirounga Bay. Upon tag application, we will tie the smaller skiff off
    to the mooring at Fisherman's Bay and follow the shark aboard the larger
    vessel. Future research planned for the white shark will be carried out
    at Southeastern Farallon Island and will be directed toward
    understanding the predatory-prey relationships between the white shark
    and its pinniped prey.

                                Y  CHANNEL               SOUTH FARALLON ISLAND
                                                                              -~i~ Mirounga angus/iostris
                                                                                  ~,Z/ophous cc/ifornionus

                                                                 A�LOW
          INDIAN     U                                              ARCH             GARBAGE GULCH
             HEAD

                                           8+                                            EAST LANDING_/  43 �

                                                                  MUSSEL
    (ca. Ikm)                                                      FLAT                             hSEA
                                 1/              MIROUNGA                                           PIGEON
                                                     BAY,                                            GULCH
                                                                           '3~~~~~~~~~~
                                                                       9+               12
                        TIME OF YEAR                                         a(9-I6tagged        4
         OCT 15   18   21   24    27    30                        I                 internally)  2 -
       0800'       ''''IIIIII5~iO~~~m-..
                     oeoo i i                                 ~~~~~~~~~~~~~~14  c-
       1200                 .%..;.*.
                     40  ~                       --IOin    ---                                   a
      o1600 -      P                                             Xffi'-
    U-       '0�(2)         (3)   (4)                       tagged
                  o                                       ~~~~~~~~~~~~~~~~externally    N
    0    NOV I    4      7    10   13   16   19                                                   N
    rO800                           1/ 310~1~9~1~~:  Ipi I  I   WHITE SHARK
            L                          (14) 00           IDENTIFICATIONS
                                                          4 3 5.25mnTL (tagged)             0  50  100      200
        1600 -                        :O-P;.5mL                                             ...
                     1    (4)         (1)52mT
                                                          Y = 6.00m TL                            meters
             Li BAITING         -  SHARK SIGHTING        S   4.25mTL (tagged)
    3                                                    E�~~~~~~~~~~~~~~~~~~~~E=3.50m T  13'0

                    I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~c

                                            t                                             4      1~~~~~~~~~~~~~~~~~~~~~~~~~~o

                   Harbor Porpoise, Phocoena phocoena, in the
                             Gulf of the FaralTlTones
                           National Marine Sanctuary

                             Isadore D. Szczepaniak
                    Department of Ornithology and Mammology
        California Academy of Sciences, San Francisco, California 94118

         The harbor porpoise, Phocoena phocoena, is the smallest cetacean
    found in northern California waters.  The average adult length is 1.5 to
    1.6 m and the average adult weight is 45-60 kg. Maximum length and
    weight of North Pacific harbor porpoise are 1.86 m and 90 kg. Females
    are slightly larger than males. Length at birth ranges from 65-90 cm
    and birth weight is approximately 5 kg.

         The body is robust and chunky. The snout is blunt with no
    prominent forehead or beak. There is a single, crescent shaped
    blowhole. The dorsal fin is triangular with a blunt tip. The small
    flippers are oval in shape and taper to a blunt point. The flukes are
    distinctly notched.

         The color pattern is variable, usually dark brown, black or gray
    above and light brown, gray or white below. The flukes, flippers and
    dorsal fin are usually dark gray or black.

         The harbor porpoise has a circumpolar distribution in the northern
    hemisphere. It is found in the cool, shallow ice-free waters of the
    North Atlantic and North Pacific including adjacent bays, rivers and
    estuaries. In the eastern North Pacific they can be found from Point
    Barrow, Alaska to Morro Bay, California (Leatherwood, Reeves, Perrin and
    Evans, 1982). They are the most common nearshore cetacean north of
    Morro Bay. Historically they have been known to inhabit San Francisco
    Bay, but there are few records of porpoise sightings in San Francisco
    Bay in the last 10 years (Szczepaniak, Webber and Markowitz, in prep.).

         Harbor porpoise are not very gregarious, and sightings are usually
    of single animals or of groups of up to 10 animals. The mean group size
    of harbor porpoise sightings in the Gulf of the Farallones is 2.6 animals
    (Szczepaniak, Webber and Markowitz, in prep). On 4 occasions groups of
    20 or more animals were encountered in the Gulf of the Farallones.
    Harbor porpoise are shy and elusive and rarely, if ever, do they approach
    vessels to ride the bow wave.

        Juvenile rockfish (Scorpaenidae), northern anchovy (Engraulis
    mordax), Pacific hake (Merluccius productus), Pacific tomcod (Microgadus
    proximus) and market squid (Loligo opalescens) are the major prey items
    of harbor porpoise in the GulTf--f-the Farallones (Jones, 1981).

         Known predators of harbor porpoise along the coast of California
    are the great white shark (Carcharodon carcharias) and the killer whale
    (Orcinus orca).

                                        - 37 -

                                                                           38

         Parturition in harbor porpoise off California occurs from May to
    July and mating takes place from June through August (Stuart and
    Morejohn, 1980). Harbor porpoise reach sexual maturity at approximately
    3-6 years (Fisher and Harrison, 1970; Van Utrecht, 1978). Although
    females usually give birth every two years, there is some evidence that
    they can calve in successive years (Fisher and Harrison, 1970; Smith and
    Gaskin, 1983). The maximum recorded lifespan of harbor porpoise is 13
    years, but few appear to live beyond 7-8 years (Gaskin and Blair, 1977;
    Stuart and Morejohn, 1980).

         Beginning in 1982 there was an increase in set-net fishing vessels
    operating in California waters. Associated with the increase in fishing
    activities was an increase in the incidental kill of marine birds and
    marine mammals. The estimated annual take of harbor porpoise is 200-300
    animals (Hanan and Diamond, in prep.). From 1972-1981, a total of 45
    harbor porpoise were reported stranded in the Gulf of the Farallones and
    adjacent waters. From 1982-1985, a total of 123 harbor porpoise were
    collected in the same area, 33% of which showed direct evidence of gill-
    net entanglement (Szczepaniak, Webber and Markowitz, in prep.).

         This high porpoise kill prompted studies to determine abundance and
    stock structure of harbor porpoise in the eastern North Pacific,
    particularly along the coast of California. Dohl, Guess, Duman and Helm
    (1983) estimated the number of harbor porpoise found in California
    waters as 1600-3000 animals. Their estimate was based on results of
    aerial surveys which were found to be relatively ineffective at sighting
    harbor porpoise (Kraus, Gilbert and Prescott, 1983). As a result this
    estimate was probably too low. Based on data collected during four
    shipboard surveys Barlow (in press) estimated that the number of harbor
    porpoise inhabiting California waters is 8,865 animals. Barlow reported
    that the population size of harbor porpoise in the Gulf of the
    Farallones to Bodega Bay region to be 89 animals. He explained that
    very little of the area in the Gulf of the Farallones was surveyed and
    as a result he had low confidence in that estimate (Barlow, personal
    communication).

         Since 1977, over 1,000 sightings of harbor porpoise were collected
    from whale watching vessels, Cordell Bank Expeditions research vessels
    or dedicated survey vessels in the Gulf of the Farallones and adjacent
    waters (Szczepaniak, Webber and Markowitz, in prep.). Based on data
    collected, harbor porpoise in the Gulf of the Farallones seem to display
    the following depth distribution: linearly increasing from shore to
    35 m, linearly decreasing from 35 m to 125 m, and zero abundance in
    waters deeper than 125 m.

         Although Dohl, Guess, Duman and Helm (1983) recorded most harbor
    porpoise sightings within 2.5 nm of shore in the Gulf of the Farallones,
    the majority of harbor porpoise sightings (59.9%) occurred between 2.5
    and 6.0 nm from shore. This seaward displacement of harbor porpoise
    distribution is probably a function of underwater topography. The broad
    Farallon Basin provides a shallow, protected habitat for harbor
    porpoise.

                                                                          39

         Harbor porpoise sightings in this region appear to be related to
    tidal activity. In a study funded by the Gulf of the Farallones
    National Marine Sanctuary 70% of harbor porpoise sightings occurred
    during the flood-high slack period.

        Dohl, Guess, Duman and Helm (1983) found that harbor porpoise
    abundance in the Gulf of the Farallones varied according to the region
    of the gulf. The Gulf of the Farallones was divided into 4 quadrants
    and density ranged from 0 - 0.25 animals/km2. Based on surveys
    conducted in September and October, 1986. porpoise density in the same
    quadrants ranged from 0 - 2.4 animals/km . The area bordered by
    San Francisco, the San Francisco Bay Entrance Buoy and Duxbury Point was
    found to be the area of greatest porpoise abundance. The total porpoise
    population in the Gulf of the Farallones was calculated to be 1033
    animals. Barlow (in press) found that approximately 23% of porpoises
    are not sighted by the primary observers. Correcting the population
    count for the animals not sighted, the total population of harbor
    porpoise in the Gulf of the Farallones is estimated as 1268 animals.

                               LITERATURE CITED

    Barlow, J. (In press). Abundance estimation for harbor porpoise
         (Phocoena phocoena) based on ship surveys along the coasts of
         California, Oregon and Washington.

    Dohl, T.P., R.D. Guess, M.L. Duman, R.C. Helm. 1983. Cetaceans of
         central and northern California, 1980-1983: status, abundance and
         distribution. Report prepared for U.S. Minerals Management
         Service, contract #14-12-0001-29090.

    Fisher, H.D., and R.J. Harrison. 1970. Reproduction in the common
         porpoise (Phocoena phocoena) of the North Atlantic. J. Zool.
         161:471-486.

    Gaskin, D.E., and B.A. Blair. 1977. Age determination of harbor
         porpoise, Phocoena phocoena (L.) in the western North Atlantic.
         Can. J. Zoo.355: 8-30.

    Hanan, D.A., and S.L. Diamond. (In prep.). The incidental take of
         harbor porpoise in California fisheries.

    Jones, R.E. 1981. Food habits of smaller marine mammals from Northern
         California. Proc. C.A.S. 42:409-433.

    Kraus, S.D., J.R. Gilbert, J.H. Prescott. 1983. A comparison of
         aerial, shipboard, and land-based survey methodology for the harbor
         porpoise, Phocoena phocoena. Fish. Bull. 81:910-913.

    Leatherwood, S., R.R. Reeves, W.F. Perrin, W.E. Evans. 1982. Whales,
         dolphins and porpoises of the eastern North Pacific and adjacent
         Arctic waters. NOAA Tech. Rept. NMFS Circ 444. 245 pp.

                                                                          40

    Stuart, L.J., and G.V. Morejohn. 1980. Developmental patterns in
        osteology and external morphology in Phocoena phocoena. Rept. Int.
        Whaling Comm. Spec. Iss. 3:133-142.

    Szczepaniak, I.D., M.A. Webber, H. Markowitz (In prep.). Sightings and
         strandings of harbor porpoise, Phocoena phocoena, in the Gulf of
         the Farallones and adjacent waters.

    van Utrecht, W.L. 1978. Age and growth in Phocoena phocoena, Linnaeus
         1758 (Cetacea:Odontoceti) from the North S--ea.  Bijdragen tot de
         Dierkunde 48(1):16-28.

                                 Cordell Bank:
                         What We Know and What We Don't

                              Robert W. Schmieder
                            Cordell Bank Expeditions
               4295 Walnut Blvd., Walnut Creek, California 94596

                                  I NTRODUCTI ON

         Lying 20 miles offshore west of Pt. Reyes, the rocky seamount
    called Cordell Bank is tantalizingly close and frustratingly far. For
    ten years we have mounted expeditions to explore and document this
    watery oasis. The first thing we found was that it harbors an
    extraordinarily vigorous and photogenic community of benthic organisms,
    algae and invertebrates, and supports large numbers of fish, birds and
    marine mammals. This community is so productive that the National
    Oceanic and Atmospheric Administration (NOAA) is in the process of
    designating it as a national marine sanctuary.

         But as much as we have learned about Cordell Bank, there remain
    large gaps in our description and understanding of this remarkable
    place. Doubtless some of these blanks will be filled in by future
    expeditions. Perhaps it will be of value to describe what we presently
    know, and what we presently don't know. If this looks like a program
    for research, well, that's not entirely accidental!

                                  WHAT WE KNOW

         By and large, we know the recent history of Cordell Bank. We know
    that it was accidentally discovered on October 22, 1853, by George
    Davidson of the U.S. Coast and Geodetic Survey. Davidson was passing
    Pt. Reyes in the fog and made a single cast of the lead of 30 fathoms.
    Some 16 years later, Edward Cordell, also an Assistant in the Coast and
    Geodetic Survey, made five separate attempts to locate the Bank, finally
    succeeding on June 18, 1869. Cordell came from Germany, from the town
    of Philippsburg, near Karlsruhe. He was active in the revolution of
    1848, was charged with high treason, and escaped to America. Thanks to
    records in the archives in the U.S. and in Germany, we know his ancestry
    back five generations, and where he was and what he was doing almost
    every day of his adult life.

         We also have a general understanding of the geologic history of
    Cordell Bank. The Bank itself is a huge rock of granite, formed as part
    of the Sierra Nevada and transported from Southern California by
    movement along the San Andreas fault. From a highly detailed
    bathymetric survey carried out by NOAA in 1985, the topography of the
    Bank is known perhaps as well as any place in the ocean. An. exciting
    discovery was that the hard rocks carry the record of their sculpturing:
    cut into the Bank is a series of terraces formed when the level of the
    ocean was lower than today. The details of the terraces are sufficient
    to indicate that the topography of the Bank was almost entirely
    controlled by this surf erosion, and to give precise depths for the
    minima and maxima of the sea level.

                                         -41-

                                                                          42

        We also know something of the oceanic conditions at Cordell Bank:
    During most of the year, relatively strong currents sweep southward, the
    so-called California Current. This current, the topography of the
    continental shelf, and the Coriolis effect combine to cause upwelling,
    the slow movement of cold water from deep regions far offshore to
    shallower regions nearshore. This cold water is loaded with organic
    materials that can be used by algae and other organisms as food, with
    the result that a lush population grows where upwelling occurs. Cordell
    Bank is a prime recipient of this upwelled water, which partially
    accounts for its biological activity.

         But another major factor is the clarity of the water: visibility
    normally is greater than 20 meters, sometimes more than 30 meters. This
    means that the light penetrates to the rocks lying shallower than these
    depths, providing energy for photosynthesis. Growth of plants in turn
    provides food for invertebrates, which in turn support fish, birds, and
    mammals. We find the dense biological cover on the shallowest ridges
    and pinnacles; it thins out with increasing depth.

         The general appearance of the bottom is now reasonably well-
    documented in photographs taken on our expeditions. It has a
    characteristic knobby appearance: there are lumps and bumps, typically
    50 cm high, covered with sponges, tunicates, and anemones. This
    knobbiness is an expression of the fact that the main limitation to the
    number of individuals is available substrate. One organism, the
    California hydrocoral Allopora californica, constructs rigid tree-like
    colonies that are encrusted by other animals.  Besides the texture of
    the bottom, the color is characteristic: due to fluorescence in the
    strawberry anemone, Corynactis californica, diving visitors to Cordell
    Bank are treated to a blaze of red color, even at depths of more than 50
    meters, where there is no red light.

         We now have a species list with about 450 entries. This probably
    represents more than 80% of the species larger than a few mm. Of
    course, there is a plethora of microscopic organisms, of which we have
    identified about 30, a tiny fraction of what's there. The phyla with
    most identifications so far are: Mollusca (138 species), Arthropoda
    (29), Annelida (29), Porifera (25), and Cnidaria (15). Essentially all
    the birds (47 species), fish (38) and mammals (14) that regularly
    frequent Cordell Bank have been sighted, but their habits are the
    subject of continuing study.

                               WHAT WE DON'T KNOW

         There are, of course, many relatively small or straightforward
    issues that remain to be resolved: completion of the species list,
    detailed numerical counts to elucidate statistical differences from one
    place on the Bank from others, detailed description of the topography of
    specific sites on a scale of meters, and so on. The vast majority
    (perhaps 97%) of the Bank lies at depths too deep for diving.
    Exploration of this important area is probably best done with a remotely
    operated vehicle (ROV). But there are many larger issues about which we
    have, as yet, no information. These questions are of wider significance

                                                                          43

    than just Cordell Bank: they relate to the general nature and evolution
    of the landscape and marine biological populations. To the extent that
    Cordell Bank may provide insight into these issues, we will find value
    in pursuing the answers at the Bank.

        One of the most significant questions is the relationship of the
    populations on the Bank to the populations on the mainland. The Bank is
    like an island: relatively small and isolated, yet in communication with
    the large reservoir of the mainland. There exists a model for insular
    populations in which immigration from the mainland increases the number
    of species, while local extinction decreases them. To what extent does
    the community on Cordell Bank fit this description? Alternatively, we
    could ask whether it is possible to formulate a theory of underwater
    islands, taking into account the currents, depth, light penetration,
    etc. To reasonably test such models, we will need a much more extensive
    sample of the populations on Cordell Bank.

         Another important question relates to the variation of the
    communities with time. Is the Bank in equilibrium? That is, are the
    relative numbers of the various species and the numbers of individuals
    relatively constant, or are there major changes occurring? Equilibrium
    does not mean total absence of change, of course. In fact, the Bank has
    many tiny pinnacles and ridges, each of which might be considered to be
    a tiny local island. These individual sites are small enough that a
    chance immigration could suddenly establish a population, say, of
    barnacles on one ridge but leave another ridge unpopulated. In the same
    way, the ridges are so small that normal fluctuations will sometimes
    lead to local extinction on a particular ridge. This exchange of
    species among the local sites could be going on constantly, producing an
    equilibrium, but clearly it is not static. We have., at present,
    practically no details about these processes at Cordell Bank.

         A related question is the response of the Bank to trauma. What
    would happen if one species, say, hydrocoral, were suddenly depleted?
    Which organisms would be the first colonizers in an area that is
    suddenly denuded? If equilibrium exists, how long would it take to re-
    establish it if it were suddenly altered, say, by a chemical spill that
    killed a large number or fraction of the population? Some questions
    like these are susceptible to experiment: in 1982 we actually cleared a
    small area completely, and returned-in 1982 to examine it. We found
    that the area was exclusively, and completely, covered with Corynactis
    anemones. Many of these questions come under the general title of
    robustness: is Cordell Bank robust or fragile? At present, no one
    knows the answer.

                                  CONCLUS IONS

         It is easy to see that what we don't know about Cordell Bank far
    exceeds what we do know at the present time. But it is precisely those
    questions that are unanswered that are relevant to areas beyond Cordell
    Bank, and are therefore the most important. It is a piece of good
    fortune that the special conditions at Cordell Bank probably will make
    possible the investigation of some of the significant questions

                                                                          44

    described earlier. If so, the benefits of detailed study of the natural
    laboratory provided at Cordell Bank will far exceed its cost, and might
    even be fun in the process!

                                 BIBLIOGRAPHY

    Federal Register. 1981. Placement of Cordell Bank, Calif., on the
        Marine Sanctuary List of Recommended Areas. Vol. 46, No. 168,
         p. 43731.

    Federal Register. 1983. Announcement of Cordell Bank as an Active
         Candidate for National Marine Sanctuary Designation. Vol. 48,
         No. 127, pp. 30178-30180.

    Schmieder, R.W. 1984. Cordell Bank: Marine Sanctuary Candidate Rises
         from Obscurity. Ocean Magazine, Vol. 17, No. 4, pp. 22-25.

    Schmieder, R.W. 1985. Cordell Bank Expeditions, 1978-1979. National
         Geographic Research Reports, 1979 Projects, pp. 603-611.

    Schmieder, R.W. 1987. Terraces, Tilting, and Topography of Cordell
         Bank, California. California Geology, in press.

    Weisburd, S. 1986. Mapping an Underwater Oasis: The Cordell Bank
         Rediscovered.   Sci. News., Vol. 130, No. 16, pp. 250-251.

                                                          r3oDF-4A
                                                            &4Y

    COIRt)?LL &1iJK

                                                                                                                                        LA4IEA'

                                 FARALLOd                                                             iA/C5
                                   ISLANDtS

                                Figure 1. Location of Cordell Bank relative to the
                                              coastline, north of San Francisco                                                U

                                                                    46

      /_

                                                       I

            Figure 2. Contour Map of Cordell Bank
                      with locations of several shallow peaks
                      indicated in fathoms (1 fathom = 6 feet)

    G O 787-727/79.54                                     +

                                                                                                                   47

    ACKNOWLEDGEMENTS

    The Marine and Estuarine Management Division wishes to acknowledge the support provided by the Point Reyes
    National Seashore, who graciously provided their Clem Miller Environmental Education Center for this
    Symposium, and the Environmental Action Committee of West Marin. Their support in this cooperative effort was
    vital to the success of this Symposium.