[Federal Register Volume 59, Number 4 (Thursday, January 6, 1994)]
[Proposed Rules]
[Pages 852-862]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-90]


[[Page Unknown]]

[Federal Register: January 6, 1994]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AB66

 

Endangered and Threatened Wildlife and Plants; Revised Proposed 
Critical Habitat Determination for the Delta Smelt

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: The Fish and Wildlife Service (Service) revises its proposed 
designation of critical habitat for the delta smelt (Hypomesus 
transpacificus) originally published on October 3, 1991, concurrently 
with the proposal to list the species, pursuant to the Endangered 
Species Act of 1973, as amended (Act). The final rule listing the delta 
smelt as a threatened species was published on March 5, 1993. In the 
final rule, the Service postponed the decision on critical habitat 
determination for up to 1 year beyond the date that the final rule was 
due (October 3, 1993) in accordance with section 4(b)(6)(C)(ii) of the 
Act. The Service has refined the primary constituent elements described 
in the original critical habitat proposal. This revised proposed rule 
supersedes all aspects of the Service's previous proposal. Critical 
habitat designation for the delta smelt would provide additional 
protection under section 7 of the Act with regard to activities that 
require Federal agency action. As required by section 4 of the Act, the 
Service will consider economic and other relevant impacts prior to 
making a final decision on the size and configuration of critical 
habitat. The Service solicits data and comments from the public on all 
aspects of this revised proposal.

DATES: Comments from all interested parties must be received by March 
7, 1994. Public hearing requests must be received by February 22, 1994.

ADDRESSES: Comments and materials concerning this proposal should be 
sent to the Acting Field Supervisor, Fish and Wildlife Service, 
Sacramento Field Office, 2800 Cottage Way, room E-1803, Sacramento, 
California 95825-1846. Comments and materials received will be 
available for public inspection, by appointment, during normal business 
hours at the above address.

FOR FURTHER INFORMATION CONTACT: Dale Pierce, Sacramento Field Office 
(see ADDRESSES section) at (916) 978-4866.

SUPPLEMENTARY INFORMATION:

Background

Previous Service Action

    In the January 6, 1989 (50 FR 554), Animal Notice of Review, the 
Service included the delta smelt as a category 1 candidate species. 
Category 1 includes species for which data in the Service's possession 
are sufficient to support proposals for listing. On June 29, 1990, the 
Service received a petition dated June 26, 1990, from Dr. Don C. Erman, 
President-Elect of the California-Nevada Chapter of the American 
Fisheries Society, to list the delta smelt as an endangered species 
with critical habitat. The Service made a 90-day finding that 
substantial information had been presented indicating that the 
petitioned action may be warranted and announced this decision in the 
Federal Register on December 24, 1990 (55 FR 52852). On October 3, 1991 
(56 FR 50075), the Service published a proposal to list the delta smelt 
as a threatened species and to designate critical habitat. This 
proposed rule constituted the 12-month petition finding in accordance 
with section 4(b)(3)(B) of the Act.
    Critical habitat was proposed for areas of all water and all 
submerged lands below ordinary high water and the entire water column 
bounded by and contained within Suisun Bay (including the contiguous 
Grizzly and Honker Bays), the length of Montezuma Slough, portions of 
the Sacramento River, portions of the Sacramento-San Joaquin Delta, 
portions of the San Joaquin River, and the contiguous water bodies in 
between (a complex of bays, dead-end sloughs, channels typically less 
than four meters deep, marshlands, etc.), California. The public 
comment period opened on the date of publication of the proposed rule 
(October 3, 1991) and closed on January 31, 1992.
    The Service published a notice of public hearing on the proposed 
rule on December 19, 1991 (56 FR 65877). Public hearings were conducted 
in California on January 9, 1992, in Sacramento; on January 14, 1992, 
in Santa Monica; and on January 16, 1992, in Visalia. At each meeting, 
testimony was taken from 1 p.m. to 4 p.m. and from 6 p.m. to 9 p.m.
    The final rule listing the delta smelt as a threatened species was 
published on March 5, 1993 (58 FR 12854). In the final rule, the 
Service postponed the decision on critical habitat designation for up 
to 1 year beyond the date that the final rule was due (October 3, 1993) 
in accordance with section 4(b)(6)(C)(ii) of the Act. The economic 
analysis necessary to determine critical habitat was still in progress 
at that time. On March 16, 1993 (58 FR 14199), the Service published a 
notice that the public comment period on the proposed designation of 
critical habitat for the delta smelt was reopened until April 30, 1993, 
to allow the Service to consider any information that previously had 
not been submitted.

Revisions to the October 3, 1991, Critical Habitat Proposal

    The Service is required to base critical habitat designations on 
the best scientific and commercial data available (50 CFR 424.12). 
Subsequent to publication of the October 3, 1991, proposed rule, the 
Service received new information on the current distribution of the 
delta smelt, primarily from other State and Federal agencies.
    Based primarily on information gathered by the California 
Department of Fish and Game (Dale Sweetnam, California Department of 
Fish and Game, pers. comm., 1993) and University of California, Davis 
(Lesa Meng, University of California, pers. comm., 1993), the Service 
proposes to expand the geographic extent of critical habitat to include 
additional areas now known to constitute important spawning habitat. In 
1993, delta smelt spawned in the Sacramento River, at least as far 
upstream as Sacramento and Barker, Lindsey, Cache, Georgiana, Prospect, 
Beaver, Hog, and Sycamore Sloughs (Dale Sweetnam, pers. comm., 1993). 
In 1991, when delta smelt had all but disappeared from Suisun Marsh, 
relatively large numbers of delta smelt were caught in Suisun Slough, 
as far upstream as Suisun City (Lesa Meng, pers. comm., 1993). For 
these reasons, the proposed critical habitat has been revised to 
encompass these upstream habitats. Protection of these upstream 
spawning habitats is essential to ensure recovery of the species. 
Hence, this rule proposes critical habitat for the following geographic 
area: Areas of all water and all submerged lands below ordinary high 
water and the entire water column bounded by and contained in Suisun 
Bay (including the contiguous Grizzly and Honker Bays); the length of 
Goodyear, Suisun, Cutoff, First Mallard (Spring Branch), and Montezuma 
Sloughs; and the existing contiguous waters contained within the Delta. 
As used in this rule, the term ``Delta'' refers to all tidal waters 
contained within the legal definition of the Sacramento-San Joaquin 
Delta, as delineated by section 12220 of the State of California's 
Water Code of 1969.
    In an April 23, 1993, letter, received during the public comment 
period, the Environmental Protection Agency (EPA) requested that new 
scientific information presented in its draft proposed Bay/Delta water 
quality standards be considered in the Service's designation of 
critical habitat. The Service has used this information to refine the 
primary constituent elements described in the original critical habitat 
proposal. (The term ``primary constituent element'' is defined in the 
``Primary Constituent Elements'' section of this rule.) The Service's 
original proposal listed the following constituent elements: Space for 
population growth, cover or shelter, maintenance of appropriate 
littoral zone reproduction habitat to sustain embryos and to rear 
larvae and juveniles, and 0-2 parts per thousand (ppt) salinities 
during the January to June delta smelt reproductive season. As part of 
the background for formulation of its proposed water quality standards, 
EPA analyzed the number of days that low salinity (2 ppt) water 
historically was located at three positions in Suisun Bay. The revised 
primary constituent elements incorporate this new information. As 
described in the ``Primary Constituent Elements'' section of this rule, 
the Service has revised the primary constituent elements to include 
those features that provide temporal and spatial variability of low 
salinity waters that will deter further invasion of exotic species, 
produce high zooplankton densities for food, and simulate natural 
processes and historical conditions. The primary constituent elements 
also describe in detail the months that each delta smelt life stage 
requires protective habitat conditions.
    After considering the information presented by EPA, the Service has 
determined that, if implemented, EPA's proposed water quality standards 
would likely significantly affect critical habitat as proposed in the 
October 3, 1991, rule. Consequently, the Service is proposing this 
revised rule to reduce the potential for inconsistencies between EPA's 
standards and the Service's proposed critical habitat. Resolving the 
inconsistencies will afford the smelt the same or better protection as 
would have been achieved through the earlier proposal.

Relationship Between Fish and Wildlife Service and EPA Actions

    The Clean Water Act and Endangered Species Act as written do not 
specify how government actions should be coordinated or agency 
conflicts should be resolved. However, because the Service and EPA 
recognize that their proposed regulatory actions overlap both 
biologically and economically, both agencies are working closely to 
provide a comprehensive, ecosystem-based approach to the protection of 
the fish and wildlife resources of the San Francisco Bay/Sacramento-San 
Joaquin Delta Estuary. This coordination should also provide a set of 
regulatory actions that are integrated in both substance and timing.
    Section 7 of the Endangered Species Act requires that all Federal 
agencies ensure that their actions do not jeopardize the continued 
existence of listed species or adversely modify listed species' 
critical habitat. EPA's proposed action to designate water quality 
standards must comply with the section 7 requirement. EPA has initiated 
a formal consultation process under section 7. Additionally, the Clean 
Water Act requires protection of the most sensitive use within each 
category of designated uses. Protection of endangered and threatened 
species is considered a designated use within the meaning of the Clean 
Water Act; therefore, a species listing under the Endangered Species 
Act provides one method to identify the most sensitive use within the 
designated uses of a water body.
    Biologically, the proposed critical habitat for the delta smelt and 
the salinity criteria that constitute EPA's proposed water quality 
standards are directly related. Specifically, the occurrence of 
salinities of 2 parts per thousand (ppt) in Suisun Bay was identified 
as a critical habitat primary constituent element in the October 3, 
1991, critical habitat proposal. Subsequent scientific publications 
indicate that salinities associated with the distribution of delta 
smelt may provide the best basis for setting standards for many species 
that are affected by freshwater discharge from the Bay/Delta Estuary. 
Favorable conditions from February through June are extremely important 
to the abundance and reproductive success of almost all species that 
live in or migrate through the upper Bay/Delta Estuary. EPA's proposed 
water quality standards address the location of 2 ppt salinities from 
February to June and, therefore, address both critical habitat 
requirements for delta smelt and a range of interrelated parameters 
that affect other species that rely on estuarine habitat.

Habitat Requirements

    Historically, the delta smelt is thought to have occurred from 
Suisun Bay upstream to the city of Sacramento on the Sacramento River 
and Mossdale on the San Joaquin River (Moyle et al. 1992). Recently, 
however, Wang (1991) recorded larval delta smelt from the Sacramento 
River as far north as its confluence with the Feather River. The delta 
smelt is an euryhaline species (tolerant of a wide salinity range) that 
spawns in fresh water and has been collected from estuarine waters up 
to 14 grams per liter (ppt) salinity (Moyle et al. 1992). For a large 
part of its annual life span, this species is associated with the 
freshwater edge of the entrapment zone (mixing zone at the saltwater-
freshwater interface), where the salinity is approximately 2 ppt 
(Ganssle 1966, Moyle et al. 1992, Sweetnam and Stevens 1993).
    The delta smelt is adapted to living in the highly productive 
Sacramento-San Joaquin River Estuary (Estuary) where salinity varies 
spatially and temporally according to tidal cycles and the amount of 
freshwater inflow. (The term estuary refers to a partially enclosed 
water body of variable salinity with freshwater and seawater inflow.) 
Despite this tremendously variable environment, the historical Estuary 
probably offered relatively constant suitable habitat conditions to 
delta smelt, which could move upstream or downstream with the 
entrapment zone (Peter Moyle, University of California, pers. comm., 
1993). Since the 1850s, however, the amount and extent of suitable 
habitat for the delta smelt has declined dramatically. The advent in 
1853 of hydraulic mining in the Sacramento and San Joaquin Rivers led 
to increased siltation and alteration of the circulation patterns of 
the Estuary (Nichols et al. 1986, Monroe and Kelly 1992). The 
reclamation of Merritt Island for agricultural purposes in the same 
year marked the beginning of the present-day cumulative loss of 94 
percent of the Estuary's tidal marshes (Nichols et al. 1986, Monroe and 
Kelly 1992).
    In addition to this degradation and loss of estuarine habitat, the 
delta smelt has been increasingly subject to entrainment, upstream or 
reverse flows of waters in the Delta and San Joaquin River, and 
constriction of habitat in the less productive, deep-water river 
channels of the Delta (Moyle et al. 1992). These adverse conditions are 
primarily a result of the steadily increasing proportion of water 
diverted from the Delta by the Federal and State water projects (Monroe 
and Kelly 1992). Water delivery through the Federal Central Valley 
Project began in water year 1940. The State Water Project began 
delivering water in 1968. However, the proportion of fresh water being 
diverted has increased since 1983 and has remained at high levels 
(Moyle et al. 1992). The high proportion of fresh water exported has 
exacerbated the already harsh environmental conditions experienced by 
the delta smelt during the recent 6-year drought. The March 5, 1993 (58 
FR 12854), final rule listing the delta smelt as a threatened species 
describes in detail the factors that have led to this species' decline.
    This revised proposed rule to designate critical habitat for the 
delta smelt focuses on habitat conditions required during specific life 
stages (spawning, larval and juvenile transport, rearing, and adult 
migration) of this annual species to ensure its eventual recovery. 
Shortly before spawning, adult delta smelt migrate upstream from the 
highly productive brackish-water habitat associated with the entrapment 
zone to disperse widely into river channels and tidally-influenced 
backwater sloughs (Radtke 1966, Moyle 1976, Wang 1991). Migrating 
adults with nearly mature eggs have been taken at the Central Valley 
Project's Tracy Pumping Plant from late December 1990 to April 1991 
(Wang 1991).
    Delta smelt spawn in shallow, fresh or slightly brackish water 
upstream of the entrapment zone (Wang 1991). Most spawning occurs in 
tidally-influenced backwater sloughs and channel edgewaters (Moyle 
1976; Wang 1986, 1991; Moyle et al. 1992). Although delta smelt 
spawning behavior has not been observed (Moyle et al. 1992), the 
adhesive, demersal eggs are thought to attach to substrates such as 
cattails and tules, tree roots, and submerged branches (Moyle 1976, 
Wang 1991). In the Delta, spawning is known to occur in the Sacramento 
River and in Barker, Lindsey, Cache, Georgiana, Prospect, Beaver, Hog, 
and Sycamore Sloughs (Wang 1991; Dale Sweetnam, pers. comm., 1993). 
Delta smelt also spawn north of Suisun Bay in Montezuma and Suisun 
Sloughs and their tributaries (Dale Sweetnam, pers. comm., 1993; Lesa 
Meng, pers. comm., 1993).
    The spawning season varies from year to year and may occur from 
late winter (December) to early summer (July). Moyle (1976) collected 
gravid adults from December to April, although ripe delta smelt were 
most common in February and March. In 1989 and 1990, Wang (1991) 
estimated that spawning had taken place from mid-February to late June 
or early July, with the peak spawning period occurring in late April 
and early May.
    Based on data for a closely related species, delta smelt eggs 
probably hatch in 12 to 14 days (Moyle et al. 1992). After hatching, 
larvae are transported downstream toward the entrapment zone where they 
are retained by the vertical circulation of fresh and salt waters 
(Stevens et al. 1990). The pelagic larvae and juveniles feed on 
zooplankton. When the entrapment zone is located in a broad geographic 
area with extensive shallow-water habitat within the euphotic zone 
(depths less than 4 meters), high densities of phytoplankton and 
zooplankton are produced (Arthur and Ball 1978, 1979, 1980), and larval 
and juvenile fish, including delta smelt, grow rapidly (Moyle et al. 
1992, Sweetnam and Stevens 1993). In general, estuaries are among the 
most productive ecosystems in the world (Goldman and Horne 1983). 
Estuarine environments produce an abundance of fish as a result of 
plentiful food and shallow, protective habitat for young.
    When the entrapment zone is contained within Suisun Bay, young 
delta smelt are dispersed widely throughout a large expanse of shallow-
water and marsh habitat. Dispersion in areas downstream from the State 
and Federal water pumps and in-Delta agricultural diversions protects 
young smelt from entrainment and distributes them among the extensive, 
protective, and highly productive shoal regions of Suisun Bay. In 
contrast, when located upstream, the entrapment zone becomes confined 
in the deep river channels, which are smaller in total surface area, 
contain fewer shoal areas, have swifter, more turbulent water currents, 
and lack high zooplankton productivity.
    Erkkila et al. (1950) collected young delta smelt near Sherman 
Island, at the confluence of the Sacramento and San Joaquin Rivers, in 
July and August of 1948. In studies by the California Department of 
Fish and Game, California Department of Water Resources, and Bureau of 
Reclamation, larval and juvenile delta smelt were collected from Roe 
Island in Suisun Bay north to the confluence of the Sacramento and 
Feather Rivers and east to Medford Island on the San Joaquin River 
(Wang 1991). These studies were conducted during the months of April 
through mid-July in 1989 and 1990. Through these distribution surveys, 
Wang (1991) was able to document the movement of juvenile delta smelt 
from the Delta to Suisun Bay in late June and early July. In 1990, 
young delta smelt were taken at the Tracy Pumping Plant at the end of 
February (Wang 1991).

Critical Habitat

    Critical habitat is defined in section 3(5)(A) of the Act as ``(i) 
the specific areas within the geographic area occupied by the species * 
* * on which are found those physical or biological features (I) 
essential to the conservation of the species and (II) which may require 
special management considerations or protection; and (ii) specific 
areas outside the geographical area occupied by the species at the time 
it is listed * * * upon a determination * * * that such areas are 
essential for the conservation of the species.'' The term 
``conservation,'' as defined in section 3(3) of the Act, means ``* * * 
to use and the use of all methods and procedures which are necessary to 
bring an endangered species or threatened species to the point at which 
the measures provided pursuant to this Act are no longer necessary.'' 
Therefore, areas designated as critical habitat must contain those 
physical or biological features essential to recover a species to the 
point that it no longer requires protection under the Act. Hence, 
critical habitat designation affords species additional protection 
above and beyond those of listing in that it preserves options for the 
species' eventual recovery. Section 3 further states that in most cases 
the entire range of a species should not be encompassed within critical 
habitat.
    Critical habitat designations alert Federal and State agencies, 
other organizations, and the public about the importance of an area in 
the conservation of a listed species. Critical habitat also identifies 
areas that may require special management or protection. Critical 
habitat receives protection under section 7 of the Act with regard to 
actions carried out, funded, or authorized by Federal agencies. Section 
7 requires that Federal agencies consult on actions that may affect 
critical habitat to ensure that their actions are not likely to destroy 
or adversely modify critical habitat. Section 7 also requires Federal 
agencies to confer on Federal actions that are likely to result in 
adverse modification or destruction of proposed critical habitat. Aside 
from the added protection provided under section 7, the Act does not 
provide other direct forms of protection to lands designated as 
critical habitat.
    In addition to considering biological information in designating 
critical habitat, the Service also considers economic and other 
relevant impacts of designating critical habitat. The Secretary may 
exclude areas from critical habitat when the benefits of such exclusion 
outweigh the benefits of including the areas within critical habitat, 
provided that the exclusion will not result in the extinction of a 
species.

Primary Constituent Elements

    In determining which areas to designate as critical habitat, the 
Service considers those physical and biological features that are 
essential to a species' conservation (50 CFR 424.12). The Service is 
required to list the known primary constituent elements together with a 
description of any critical habitat that is proposed. Such physical and 
biological features (i.e., primary constituent elements) include, but 
are not limited to, the following:
    (1) Space for individual and population growth, and for normal 
behavior;
    (2) Food, water, air, light, minerals, or other nutritional or 
physiological requirements;
    (3) Cover or shelter;
    (4) Sites for breeding, reproduction, rearing of offspring, 
germination, or seed dispersal; and
    (5) Generally, habitats that are protected from disturbance or are 
representative of the historic geographical and ecological 
distributions of a species.
    Following are the primary constituent elements necessary to 
conserve the delta smelt. These elements were determined in 
coordination with EPA in preparation of its proposed water quality 
standards. EPA's proposed rule to promulgate Water Quality Standards 
for Surface Waters of the Sacramento River, San Joaquin River, and San 
Francisco Bay and Delta of the State of California is published in this 
same Federal Register separate part. In its proposed rule, EPA has 
requested specific comments on several issues, including the 
possibility of modifying the Sacramento River Index for the purposes of 
developing the salinity criteria, alternative approaches to the 
averaging period used in its proposed salinity criteria, and evaluation 
of the merits of the use of difference forms of confidence intervals 
with the proposed criteria. The Fish and Wildlife Service will consider 
these comments also in developing its final rule.
    The primary constituent elements are organized by habitat 
conditions required for each life stage. The specific geographic areas 
and seasons identified for each habitat condition specified below 
represent the maximum possible range of each of these variables.
    Each of the habitat conditions specified below requires as its 
basis placement of the 2 ppt isohaline at or downstream of the 
Sacramento-San Joaquin River confluence from February through June. (An 
isohaline is a line that can be drawn to connect all points of equal 
salinity.) Furthermore, the location of the 2 ppt isohaline must vary 
according to water years because:
    (1) Temporal and spatial variability of the 2 ppt isohaline will be 
the most effective deterrent to further invasion of new introduced 
species and continued competition by those that are already 
established,
    (2) Placement of the 2 ppt isohaline in an area will also produce 
the high phytoplankton and zooplankton densities that characterize most 
healthy estuarine ecosystems, and
    (3) Variability is needed to simulate natural processes and 
historical conditions.
    Table 1 lists the number of days (based on a 14-day running 
average) that the 2 ppt isohaline must be located at Roe Island, Chipps 
Island, or the Sacramento-San Joaquin River confluence during wet, 
above normal, below normal, dry, and critically dry years to achieve 
the life-stage habitat conditions described below. These required 
salinity criteria are based on historical records of the water years 
between October 1939 (subsequent to the operation of the Federal and 
State water projects) and September 1975 (prior to the decline of the 
delta smelt) (Harry Seraydarian, EPA, in litt., 1993; Bruce Herbold, 
EPA, pers. comm., 1993). However, because no critically dry years 
occurred during this period, the salinity criteria (required number of 
days) for these years are based on an extrapolation of the data.

     Table 1.--Required Salinity Criteria for Suisun Bay to Reflect     
                      Historical Habitat Conditions                     
  [Values represent the number of days that the 2 ppt isohaline must be 
    placed at three locations within the Sacramento-San Joaquin River   
                                Estuary]                                
------------------------------------------------------------------------
                          Roe Island [km   Chipps Island  Confluence [km
       Year type               64]           [km 74]           81]      
------------------------------------------------------------------------
Wet.....................             133             148             150
Above normal............             105             144             150
Below normal............              78             119             150
Dry.....................              33             116             150
Critically dry..........               0              90             150
------------------------------------------------------------------------



    The Roe Island salinity criteria are meant to replicate natural 
spring storm cycles and are invoked only after uncontrolled runoff has 
placed the 2 ppt isohaline seaward of Roe Island. Therefore, the 
criteria for Roe Island represent the maximum number of days that the 2 
ppt isohaline must be located there.
    Spawning Habitat--Delta smelt adults seek shallow, tidally-
influenced, freshwater (i.e., less than 2 ppt salinity) backwater 
sloughs and edgewaters for spawning. To ensure egg hatching and larval 
viability, spawning areas also must provide suitable water quality 
(i.e., low concentrations of pollutants) and substrates for egg 
attachment (e.g., submerged tree roots and branches and emergent 
vegetation). Specific areas that have been identified as important 
delta smelt spawning habitat include Barker, Lindsey, Cache, Prospect, 
Georgiana, Beaver, Hog, and Sycamore Sloughs and the Sacramento River 
in the Delta, and tributaries of northern Suisun Bay. The spawning 
season varies from year to year and may start as early as December and 
extend until July.
    Larval and Juvenile Transport--To ensure that delta smelt larvae 
are transported from the area where they are hatched to shallow, 
productive rearing or nursery habitat, the Sacramento and San Joaquin 
Rivers and their tributary channels must be protected from physical 
disturbance (e.g., sand and gravel mining, diking, dredging, and levee 
or bank protection and maintenance) and flow disruption (e.g., water 
diversions that result in entrainment and in-channel barriers or tidal 
gates). Adequate river flow is necessary to transport larvae to rearing 
habitat in Suisun Bay. To ensure that suitable rearing habitat is 
available in Suisun Bay, the salinity criteria described above in Table 
1 are required. Reverse flows that maintain larvae upstream in deep-
channel regions of low productivity and expose them to entrainment 
interfere with these transport requirements. Suitable water quality 
must be provided so that maturation is not impaired by pollutant 
concentrations. The specific geographic area important for larval 
transport is confined to waters contained within the legal boundary of 
the Delta, Suisun Bay, and Montezuma Slough and its tributaries. The 
specific season when habitat conditions identified above are important 
for successful larval transport varies from year to year depending on 
when peak spawning occurs. Therefore, habitat conditions suitable for 
transport of larvae and juveniles may be required as early as February 
1 and as late as August 31.
    Rearing Habitat--Maintenance of the 2 ppt isohaline (according to 
the salinity criteria described in Table 1) and suitable water quality 
(low concentrations of pollutants) within the Estuary is necessary to 
provide delta smelt larvae and juveniles a shallow, protective, food-
rich environment in which to mature to adulthood. This placement of the 
2 ppt isohaline also serves to protect larval, juvenile, and adult 
delta smelt from entrainment in the State and Federal water projects. 
However, additional flows above those required to implement the 
February through June salinity criteria listed in Table 1 may be 
required occasionally to protect larval and juvenile delta smelt from 
being entrained in the State and Federal water projects during the 
months of July and August. These additional flows will be required when 
the previous year's abundance indices show that the adult population 
already is at low levels and late spawning conditions have led to 
distribution of larval and juvenile delta smelt upstream of the 
confluence of the Sacramento and San Joaquin Rivers in July and August. 
An area extending eastward from Carquinez Straits, including Suisun 
Bay, Grizzly Bay, Honker Bay, Montezuma Slough and its tributary 
sloughs, up the Sacramento River to its confluence with Three Mile 
Slough, and south along the San Joaquin River including Big Break, 
defines the specific geographic area critical to the maintenance of 
suitable rearing habitat. Three Mile Slough represents the approximate 
location of the most upstream extent of tidal excursion when the 
salinity criteria described in Table 1 are implemented. Protection of 
rearing habitat conditions may be required from the beginning of 
February to the end of August.
    Adult Migration--Adult delta smelt must be provided unrestrained 
access to suitable spawning habitat in a period that may extend from 
December to July. Therefore, adequate flow and suitable water quality 
must be maintained to attract migrating adults in the Sacramento and 
San Joaquin River channels and their associated tributaries, including 
Cache and Montezuma Sloughs and their tributaries. These areas also 
must be protected from physical disturbance and flow disruption during 
migratory periods.
    To conserve the delta smelt, critical habitat is proposed for an 
area encompassing the specific habitat conditions required by each life 
stage identified above. Accordingly, critical habitat is proposed for 
the following geographic area: Areas of all water and all submerged 
lands below ordinary high water and the entire water column bounded by 
and contained in Suisun Bay (including the contiguous Grizzly and 
Honker Bays); the length of Goodyear, Suisun, Cutoff, First Mallard 
(Spring Branch), and Montezuma Sloughs; and the existing contiguous 
waters contained within the Delta. The proposed critical habitat is 
contained within Contra Costa, Sacramento, San Joaquin, Solano, and 
Yolo Counties, California. The ``Proposed Regulations Promulgation'' 
section provides a precise metes and bounds description of the revised 
proposed critical habitat.

Effects of Critical Habitat Designation

    Section 7(a)(2) of the Act requires Federal agencies to ensure that 
the activities they authorize, fund, or carry out are not likely to 
destroy or adversely modify critical habitat. This Federal 
responsibility is in addition to the requirement in the same section of 
the Act that Federal agencies ensure their actions do not jeopardize 
the continued existence of any listed species.
    Jeopardy is defined at 50 CFR 402.02 as any action that would be 
expected to reduce appreciably the likelihood of both the survival and 
recovery of a listed species. Destruction or adverse modification of 
critical habitat is defined at 50 CFR 404.02 as a direct or indirect 
alteration that appreciably diminishes the value of critical habitat 
for both the survival and recovery of a listed species. The regulations 
also clearly state that such alterations include, but are not limited 
to, alterations adversely modifying any of those physical or biological 
features that were the basis for determining the habitat to be 
critical. The requirement to consider potential adverse modification of 
critical habitat is an incremental consideration above and beyond the 
review necessary to evaluate the likelihood of jeopardy and incidental 
take in section 7 consultations. In section 7 consultations, the 
Service considers the potential for adverse modification of the primary 
constituent elements identified in the critical habitat designation.
    Section 4(b)(8) of the Act requires for any proposed or final 
regulation that designates critical habitat a brief description and 
evaluation of those activities (public or private) that may adversely 
modify such habitat or may be affected by such designation. The Service 
has identified the following list of activities that, depending on the 
season of construction and scale of the project, may result in the 
destruction or adverse modification of critical habitat without 
necessarily jeopardizing the continued existence of the delta smelt:
    (1) Sand and gravel extraction in river channels or marshes;
    (2) Diking wetlands for conversion to farmland and dredging to 
maintain these dikes;
    (3) Levee maintenance and bank-protection activities, such as 
riprapping, removal of vegetation, and placement of dredged materials 
on levees of banks;
    (4) Operation of the Montezuma Slough Control Structure; and
    (5) Bridge and marina construction.
    Construction and implementation of each of these actions requires 
authorization by the Army Corps of Engineers pursuant to section 10 of 
the Rivers and Harbors Act of 1899 and section 404 of the Clean Water 
Act. Based on the Service's review of all existing or proposed projects 
that may affect the delta smelt, the great majority that would likely 
result in destruction or adverse modification of critical habitat also 
would be likely to jeopardize the continued existence of the species. 
The Service has not identified any proposed actions that might 
jeopardize the delta smelt without adversely affecting its critical 
habitat.

Considerations of Economic and Other Factors

    Section 4(b)(2) of the Act requires the Service to consider 
economic and other relevant impacts of specifying any particular area 
to be included within the critical habitat boundary. The Secretary may 
exclude any area from critical habitat should it be determined that the 
benefits of such exclusion outweigh the benefits of specifying such an 
area as part of the critical habitat unless it is determined, based on 
the best scientific and commercial data available, that the failure to 
designate such an area as critical habitat will result in the 
extinction of the species concerned.
    The impacts of designating critical habitat are in addition to the 
economic and other impacts attributable to listing of the species. 
Impacts attributable to listing include those resulting from the taking 
prohibitions under section 9 of the Act and associated regulations. 
``Take,'' as defined in section 3(18) of the Act, includes harm to a 
listed species. ``Harm'' means an act that actually kills or injures 
wildlife. Such an act may include significant habitat modification or 
degradation where it actually kills or injures wildlife by 
significantly impairing essential behavioral patterns, including 
feeding, breeding, or sheltering (50 CFR 17.3).
    Impacts attributable to listing also include those resulting from 
the responsibility of Federal agencies under section 7 to ensure that 
their actions are not likely to jeopardize the continued existence of 
endangered or threatened species. An action could be likely to 
jeopardize the continued existence of a listed species through the 
destruction or modification of its habitat regardless of whether that 
habitat has been formally designated as critical. The Act provides 
significant protection to species, including protection to their 
habitats, as a result of listing. Therefore, the direct economic and 
other impacts resulting from additional habitat protection through 
critical habitat designation may be incrementally small. In general, 
the designation of critical habitat supplements the substantive 
protection resulting from listing.
    EPA has prepared a draft Regulatory Impact Analysis on its proposed 
water quality standards. EPA's draft Regulatory Impact Analysis 
includes an economic analysis of the effects of the designation of 
critical habitat for the delta smelt. This economic analysis concludes 
that economic costs attributable to the designation of critical habitat 
for the delta smelt are relatively small and due primarily to the 
effects designation of critical habitat would have upon the five types 
of actions listed above under the section entitled ``Effects of 
Critical Habitat Designation.'' An underlying assumption of the draft 
economic analysis is that the costs associated with implementing EPA's 
proposed water quality standards for the Bay/Delta are due primarily to 
listing the delta smelt as threatened. As the Service refines its 
economic analysis, it may determine that this assumption is to some 
degree inappropriate and that some of the costs associated with 
implementing the water quality standards may be attributable to the 
designation of critical habitat.
    The costs associated with sand and gravel operations (approximately 
two aggregate operators are located in the Delta), diking or dredging 
for agricultural activities, and marina or bridge construction are 
expected to be similar. Project proponents or operators would incur 
costs associated with wetlands restoration, using a replacement ratio 
of 3 acres restored for 1 acre destroyed. The cost to restore 1 acre of 
wetlands ranges between $10,000 and $50,000. However, for some tracts 
of land, the costs associated with restoring wetlands may exceed the 
value derived from the agricultural activity, in which case the cost 
attributable to critical habitat would be the loss in agricultural 
income. The costs attributable to a designation of critical habitat are 
not expected to substantially affect levee maintenance operations 
because Federal regulatory agencies currently have restrictions that 
generally avoid adverse effects to the delta smelt. However, the 
designation of critical habitat may result in leaving the Montezuma 
Slough Control Structure's gates open from December to August rather 
than November to March.
    The Service will prepare a final economic analysis prior to making 
its final determination on critical habitat. If that analysis 
substantially differs from the draft summarized here, the Service will 
make a revised economic analysis available to the public for comment 
prior to a final determination on critical habitat.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened under the Endangered Species Act include recognition, 
recovery actions, requirements for Federal protection, and prohibitions 
against certain activities. Recognition through listing encourages and 
results in conservation actions by Federal, State, and private 
agencies, groups, and individuals. The Endangered Species Act provides 
for possible land acquisition and cooperation with the States and 
requires that recovery actions be carried out for all listed species. 
Such actions are initiated by the Service following listing. The 
protection required of Federal agencies and the prohibitions against 
taking and harm are discussed, in part, below.
    Section 7(a) of the Act, as amended, requires Federal agencies to 
evaluate their actions with respect to any species that is proposed or 
listed as endangered or threatened and with respect to its critical 
habitat, if any is being designated. Regulations implementing this 
interagency cooperation provision of the Act are codified at 50 CFR 
part 402. Section 7(a)(4) of the Act requires Federal agencies to 
confer informally with the Service on any action that is likely to 
jeopardize the continued existence of a proposed species or result in 
destruction or adverse modification of proposed critical habitat. If a 
species is subsequently listed and its critical habitat is designated, 
section 7(a)(2) requires Federal agencies to ensure that activities 
they authorize, fund, or carry out are not likely to jeopardize the 
continued existence of such a species or to destroy or adversely modify 
its critical habitat. If a Federal action may affect a listed species 
or its critical habitat, the responsible Federal agency must enter into 
consultation with the Service.
    Survival and recovery, mentioned in both the definition of adverse 
modification and jeopardy (see ``Effects of Critical Habitat 
Designation'' section), are directly related. Survival may be viewed as 
a linear continuum between recovery and extinction of the species. The 
closer a species is to recovery, the greater the certainty of the 
species' continued survival. Thus, the terms survival and recovery are 
related by the degree of certainty that the species will persist over a 
given period of time. Survival relates to viability. Factors that 
influence a species' viability include population numbers, distribution 
throughout the range, stochasticity, expected duration, and 
reproductive success. A species may be considered recovered when there 
is a high degree of certainty for the species' continued viability.
    The Act's definition of critical habitat indicates that the purpose 
of critical habitat is to contribute to a species' conservation, which, 
by definition, means recovery. Section 7 prohibitions against the 
destruction or adverse modification of critical habitat apply to 
actions that would impair survival and recovery of the listed species, 
thus providing a regulatory means of ensuring that Federal actions 
within critical habitat are considered in relation to the goals and 
recommendations of a recovery plan. As a result of the link between 
critical habitat and recovery, the prohibition against destruction or 
adverse modification of critical habitat should protect the critical 
habitat's ability to contribute fully to a species' recovery. Thus, the 
adverse modification standard may be reached closer to the recovery end 
of the survival continuum, whereas the jeopardy standard traditionally 
has been applied nearer to the extinction end of the continuum.
    Federal actions that may affect the delta smelt or its critical 
habitat, should any be designated, include those authorized, carried 
out, or funded by the Army Corps of Engineers, Bureau of Reclamation, 
National Marine Fisheries Service, and EPA. The Army Corps of Engineers 
funds projects and issues permits for water pumping and diversion 
facilities, levee construction or repair, bank protection activities, 
deep-water navigation channel dredging and dredge spoil disposal 
projects, sand and gravel extraction, marina and bridge construction, 
diking of wetlands for conversion to farmland, and tidal gate or 
barrier installation. The Bureau of Reclamation and California 
Department of Water Resources construct, operate, and/or manage water 
export facilities. EPA reviews State water quality standards and 
promulgates replacement standards, pursuant to the Clean Water Act, if 
the State standards are found to be inadequate. In 1991, EPA 
disapproved portions of the California State Water Resources Control 
Board's Water Quality Control Plan for Salinity for the San Francisco 
Bay/Sacramento-San Joaquin Delta Estuary. Accordingly, EPA has prepared 
proposed replacement standards for those portions of the State's 
salinity standards that were disapproved. Measures to protect the 
federally listed winter-run chinook salmon, for which the National 
Marine Fisheries Service has jurisdiction under the Act, also may 
affect the delta smelt and may require consultation with the Service.
    Under section 4 of the Act, listing of the delta smelt provided a 
requirement for the development of a recovery plan. The Service 
convened the Delta Native Fishes Recovery Team to prepare a recovery 
plan for declining native fishes in the Sacramento-San Joaquin Estuary. 
The recovery plan will develop a framework for Federal, State, and 
private entities to coordinate activities and cooperate with each other 
in conservation efforts. The plan will set recovery priorities and 
estimate the costs of various tasks necessary to accomplish recovery 
goals. Site-specific management actions necessary to achieve survival 
and recovery of the delta smelt and other fishes native to the Estuary 
ecosystem also will be described in this plan.

Summary of Comments and Recommendations

    During the 4-month comment period following publication of the 
October 3, 1991 (56 FR 50075), proposed rule to list the delta smelt as 
threatened and designate its critical habitat, the Service received 360 
comments (i.e., letters and oral testimony) from 348 individuals. The 
Service received several letters supporting designation of delta smelt 
critical habitat as proposed. Many local government agencies, water 
districts, business and trade associations, and other private interests 
submitted comments regarding the presumed economic effects of the 
proposed critical habitat designation on industries, planned 
activities, and development in specific municipalities or geographic 
regions of California.
    On March 16, 1993 (58 FR 14199), the Service published a notice 
that the public comment period on the proposed designation of critical 
habitat for the delta smelt was reopened until April 30, 1993, to allow 
the Service to consider any information that previously had not been 
submitted. In response, the Service received seven letters: two in 
support of critical habitat designation as proposed, four in 
opposition, and a letter from EPA requesting that the Service consider 
the biological and hydrological information described in EPA's draft 
proposed rule to promulgate Bay/Delta water quality standards.
    The proposed rule to designate critical habitat for the delta smelt 
has been revised to reflect the best scientific information currently 
available and to ensure that the Service coordinates its final actions 
with other interested Federal agencies. For this reason, the Service 
will address all comments previously received on the economic impacts, 
legal requirements, and interpretation of various provisions of the Act 
during preparation of a final rule. Additionally, comments received 
during the 60-day comment period following publication of this revised 
proposed rule will be used in preparing a final rule. Only comments 
addressing the issue of available scientific information used to revise 
this proposed rule are responded to in this document. In its final 
determination on the designation of critical habitat, the Service will 
provide a thorough discussion of all comments received in response to 
the original proposed rule and to this revised proposed rule.
    Comment: EPA requested that in its designation of critical habitat 
the Service consider the scientific information described in EPA's 
draft proposed rule to promulgate water quality standards for the Bay/
Delta.
    Service Response: The Service has substantially revised the primary 
constituent elements in this proposed rule to reflect more closely the 
historical placement of low salinity estuarine habitat in Suisun Bay. 
As part of the background for formulation of its proposed water quality 
standards, EPA analyzed the number of days that low salinity (2 ppt) 
water historically was located at the confluence of the Sacramento and 
San Joaquin Rivers, Chipps Island, and Roe Island in Suisun Bay. The 
Service has revised the primary constituent elements to include those 
features that provide temporal and spatial variability of low salinity 
waters that will deter further invasion of exotic species, produce high 
zooplankton densities for food, and simulate natural processes and 
historical conditions. The ``Primary Constituent Elements'' section of 
this revised proposed rule describes in detail the months that each 
delta smelt life stage requires protective habitat conditions. This 
revised proposal refines the primary constituent elements to more 
accurately replicate historical conditions that are needed to recover 
the delta smelt.
    Comment: One commenter stated that the Service does not have enough 
scientific data to substantiate the conclusions that the location of 
low salinity habitat in Suisun Bay is important to the recovery of the 
delta smelt, that delta smelt are associated with the saltwater-
freshwater mixing zone, or that water exports could adversely affect 
delta smelt critical habitat as currently proposed.
    Service Response: Section 4(b)(B)(2) of the Act requires that 
critical habitat designations be based on the best scientific data 
available. As discussed in the ``Habitat Requirements'' and ``Primary 
Constituent Elements'' sections of this rule, the best available 
scientific evidence shows that when the entrapment zone is located in a 
broad geographic area with extensive shallow-water habitat within the 
euphotic zone, high densities of phytoplankton and zooplankton are 
produced (Arthur and Ball 1978, 1979, 1980) and larval and juvenile 
fish, including delta smelt, grow rapidly (Moyle et al. 1992, Sweetnam 
and Stevens 1993). When the entrapment zone is contained within Suisun 
Bay, young delta smelt are dispersed widely throughout a large expanse 
of shallow-water and marsh habitat (Harry Seraydarian, EPA, in litt., 
1993). Dispersion in areas downstream from the State and Federal water 
pumps and in-Delta agricultural diversions protects young smelt from 
entrainment (diverted into man-made structures or impinged on screens) 
and distributes them among the extensive, protective, and highly 
productive shoal regions of Suisun Bay. In contrast, high exports cause 
the entrapment zone to be pulled upstream into the deep river channels 
(Moyle et al. 1992). The large river channels are smaller in total 
surface area, contain fewer shoal areas, have swifter, more turbulent 
water currents, and lack high zooplankton densities.
    Because the Service seeks to coordinate its final actions with 
other interested Federal agencies and because the Service also has 
received new distributional information since the October 3, 1991, 
proposal to designate critical habitat for the delta smelt, the Service 
hereby revises the proposal to designate critical habitat. This 
proposed rule revision is based on materials received during the public 
comment period and information received during numerous meetings and 
discussions with State and Federal agency biologists, ichthyologists, 
engineers, and hydrologists. This new proposal supersedes the October 
3, 1991, proposal.

Public Comments Solicited

    The Service intends that any final action resulting from this 
proposal will be as accurate and as effective as possible. Therefore, 
comments or suggestions from the public, other concerned governmental 
agencies, the scientific community, industry, or any other interested 
party concerning this proposed rule are hereby solicited. Comments are 
particularly sought concerning:
    (1) The reasons why any habitat (either existing or additional 
areas) should or should not be determined to be critical habitat as 
provided by section 4 of the Act;
    (2) Current or planned activities and their possible impacts on 
proposed critical habitat areas;
    (3) Any foreseeable economic or other impacts resulting from the 
proposed designation of critical habitat;
    (4) Economic values associated with benefits of designating 
critical habitat for the delta smelt; and
    (5) The methodology the Service might use, under section 4(b)(2) of 
the Act, in determining whether the benefits of excluding an area from 
critical habitat outweigh the benefits of specifying the area as 
critical habitat. Because the primary constituent elements used in 
determining which areas to propose as critical habitat for the delta 
smelt were determined in coordination with EPA in preparation of its 
proposed water quality standards, the Service also encourages the 
public, other concerned governmental agencies, the scientific 
community, industry, or any other interested party to provide comments 
or suggestions to EPA on its proposed rule to promulgate Water Quality 
Standards for Surface Waters of the Sacramento River, San Joaquin 
River, and San Francisco Bay and Delta of the State of California. The 
Fish and Wildlife Service will consider these comments also in 
developing its final rule. EPA's proposed rule is published in this 
same Federal Register separate part.
    The Endangered Species Act provides for a public hearing on this 
proposal, if requested. Requests must be received within 45 days of the 
date of publication of this revised proposal in the Federal Register. 
Such requests must be made in writing and should be sent to the Acting 
Field Supervisor, Sacramento Field Office (see ADDRESSES section).
    As stated previously, all comments that have been received during 
the preceding public comment periods on the economic impacts, legal 
requirements, and biological or ecological requirements or effects of 
critical habitat designation will be considered during preparation of a 
final rule. Additionally, comments received during the 60-day comment 
period following publication of this revised proposed rule will be used 
in preparing a final rule. The final decision on the designation of 
critical habitat will take into consideration the comments and any 
additional information received by the Service and will include any 
exclusion determinations.

National Environmental Policy Act

    The Service has determined that an Environmental Assessment and/or 
an Environmental Impact Statement, as defined under the authority of 
the National Environmental Policy Act of 1969, need not be prepared in 
connection with regulations adopted pursuant to section 4(a) of the 
Act. A notice outlining the Service's reasons for this determination 
was published in the Federal Register on October 25, 1983 (48 FR 
49244).

Regulatory Flexibility Act and Executive Order 12866

    This proposed rule has been reviewed under Executive Order 12866. 
The Department of the Interior has determined that the proposed rule 
will not have a significant economic effect on a substantial number of 
small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et 
seq.). Based on the information discussed in this rule concerning 
public projects and private activities within critical habitat areas, 
significant economic impacts will not result from the critical habitat 
designation. Also, no direct costs, enforcement costs, information 
collection, or recordkeeping requirements are imposed on small entities 
by this designation. Further, the rule contains no recordkeeping 
requirements as defined by the Paperwork Reduction Act of 1980.

Takings Implications Assessment

    The Service has analyzed the potential takings implications of 
designating critical habitat for the delta smelt in a Takings 
Implications Assessment prepared pursuant to requirements of Executive 
Order 12630, ``Governmental Actions and Interference with 
Constitutionally Protected Property Rights.'' The Takings Implications 
Assessment concludes that the designation does not pose significant 
takings implications.

References Cited

Arthur, J.F., and M.D. Ball. 1978. Entrapment of suspended materials 
in the San Francisco Bay-Delta Estuary. U.S. Dept. Interior, Bureau 
of Reclamation, Sacramento, California.
Arthur, J.F., and M.D. Ball. 1979. Factors influencing the 
entrapment of suspended material in the San Francisco Bay-Delta 
Estuary. Pages 143-174 in T.J. Conomos, editor. Pacific Division, 
Amer. Assoc. Advance. Sci., San Francisco, California.
Arthur, J.F., and M.D. Ball. 1980. The significance of the 
entrapment zone location to the phytoplankton standing crop in the 
San Francisco Bay-Delta Estuary. U.S. Dept. Interior, Water and 
Power Resources Service.
Erkkila, L.F., J.W. Moffet, O.B. Cope, B.R. Smith, and R.S. Smith. 
1950. Sacramento-San Joaquin Delta fishery resources: Effects of 
Tracy Pumping Plant and the Delta Cross Channel. U.S. Fish and 
Wildlife Service Special Scientific Rept. 56:1-109.
Ganssle, D. 1966. Fishes and decapods of San Pablo and Suisun Bays. 
Pages 64-94 in D.W. Kelley, editor. Ecological studies of the 
Sacramento-San Joaquin estuary, Part 1. Calif. Dept. Fish and Game, 
Fish Bulletin 133.
Goldman, C.R., and A.J. Horne. 1983. Limnology. McGraw-Hill Book 
Company, New York, New York.
Monroe, M.W., and J. Kelly. 1992. State of the estuary: A report on 
conditions and problems in the San Francisco Bay/Sacramento-San 
Joaquin Delta Estuary. San Francisco Estuary Project, Oakland, 
California.
Moyle, P.B. 1976. Inland Fishes of California. University of 
California Press, Berkeley, California.
Moyle, P.B., B. Herbold, D.E. Stevens, and L.W. Miller. 1992. Life 
history and status of delta smelt in the Sacramento-San Joaquin 
Estuary, California. Trans. Amer. Fish. Soc. 121:67-77.
Nichols, F.H., J.E. Cloern, S.N. Luoma, and D.H. Peterson. 1986. The 
modification of an estuary. Science 231:567-573.
Radtke, L.D. 1966. Distribution of smelt, juvenile sturgeon, and 
starry flounder in the Sacramento-San Joaquin Delta with 
observations on food of sturgeon. Pages 115-129 in J.L. Turner and 
D.W. Kelley, editors. Ecological studies of the Sacramento-San 
Joaquin Delta, Part 2. Calif. Dept. Fish and Game, Fish Bulletin 
136.
Stevens, D.E., L.W. Miller, and B.C. Bolster. 1990. Report to the 
Fish and Game Commission: A status review of the delta smelt 
(Hypomesus transpacificus) in California. Calif. Dept. Fish and Game 
Candidate Species Status Report 90-2.
Sweetnam, D.A., and D.E. Stevens. 1993. Report to the Fish and Game 
Commission: A status review of the delta smelt (Hypomesus 
transpacificus) in California. Calif. Dept. Fish and Game Candidate 
Species Status Report 93-DS.
Wang, J.C.S. 1986. Fishes of the Sacramento-San Joaquin estuary and 
adjacent waters, California: A guide to the early life histories. 
Interagency Ecological Study Program for the Sacramento-San Joaquin 
Estuary. Tech. Rept. 9.
Wang, J.C.S. 1991. Early life stages and early life history of the 
delta smelt, Hypomesus transpacificus, in the Sacramento-San Joaquin 
estuary, with comparison of early life stages of the longfin smelt, 
Spirinchus thaleichthys. Interagency Ecological Studies Program for 
the Sacramento-San Joaquin Estuary. Tech. Rept. 28.

Author

    The primary author of this proposed rule is Nadine R. Kanim, 
Sacramento Field Office (see ADDRESSES section).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Proposed Regulations Promulgation

    Accordingly, the Service hereby proposes to amend part 17, 
subchapter B of chapter I, title 50 of the Code of Federal Regulations, 
as set forth below:

PART 17--[AMENDED]

    1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500, unless otherwise noted.

Sec. 17.11  [Amended]

    2. Amend Sec. 17.11(h), in the entry in the table under FISHES for 
``Smelt, delta,'' in the column under ``Critical habitat'' by revising 
``NA'' to read ``17.95(e).''
    3. Amend Sec. 17.95(e) by adding critical habitat of the delta 
smelt in the same alphabetical order as the species occurs in 
Sec. 17.11(h).


Sec. 17.95  Critical habitat--fish and wildlife.

    (e) * * *
* * * * *

-----------------------------------------------------------------------

Delta Smelt (Hypomesus transpacificus)

    California: Areas of all water and all submerged lands below 
ordinary high water and the entire water column bounded by and 
contained in Suisun Bay (including the contiguous Grizzly and Honker 
Bays); the length of Montezuma Slough; and the existing contiguous 
waters contained within the Delta, as defined by section 12220, of 
the State of California's Water Code of 1969 (a complex of bays, 
dead-end sloughs, channels typically less than 4 meters deep, 
marshlands, etc.) as follows:
    Bounded by a line beginning at the Carquinez Bridge which 
crosses the Carquinez Strait, thence northeasterly along the western 
and northern shoreline of Suisun Bay, including Goodyear, Suisun, 
Cutoff, First Mallard (Spring Branch), and Montezuma Sloughs; thence 
upstream to the intersection of Montezuma Slough with the western 
boundary of the Delta as delineated in section 12220 of the State of 
California's Water Code of 1969; thence following the boundary and 
including all contiguous water bodies contained within the statutory 
definition of the Delta, to its intersection with the San Joaquin 
River at its confluence with Suisun Bay; thence westerly along the 
south shore of Suisun Bay to the Carquinez Bridge.

BILLING CODE 4310-55-P

TP06JA94.010


BILLING CODE 4310-55-C
    Primary Constituent Elements: Physical habitat, water, river 
flow, and salinity concentrations required to maintain delta smelt 
habitat for spawning, larval and juvenile transport, rearing, and 
adult migration.

    Dated: December 10, 1993.
Richard N. Smith,
Acting Director, Fish and Wildlife Service.
[FR Doc. 94-90 Filed 1-5-94; 8:45 am]
BILLING CODE 4310-55-P