[Federal Register Volume 59, Number 4 (Thursday, January 6, 1994)]
[Proposed Rules]
[Pages 862-869]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-91]


[[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-AC26

 

Endangered and Threatened Wildlife and Plants; Proposed 
Determination of Threatened Status for the Sacramento Splittail

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: The U.S. Fish and Wildlife Service (Service) proposes 
threatened status for the Sacramento splittail (Pogonichthys 
macrolepidotus) pursuant to the Endangered Species Act of 1973, as 
amended (Act). Sacramento splittail occur in Suisun Bay and the San 
Francisco Bay-Sacramento-San Joaquin River Estuary in California. The 
Sacramento splittail has declined by 62 percent over the last 15 years. 
This species is primarily threatened by large freshwater exports from 
Sacramento and San Joaquin River diversions, prolonged drought, loss of 
shallow-water habitat, introduced aquatic species, and agricultural and 
industrial chemicals. This proposal, if made final, would implement the 
protection and recovery provisions afforded by the Act for Sacramento 
splittail. The Service seeks all available data and comments from the 
public regarding this 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 
submitted to the Acting Field Supervisor, Sacramento Field Office, U.S. 
Fish and Wildlife Service, 2800 Cottage Way, 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, Acting Field Supervisor, 
Sacramento Field Office (see ADDRESSES section) at 916/978-4866.

SUPPLEMENTARY INFORMATION:

Background

    As used in this rule, the term ``Delta'' refers to all tidal waters 
contained within the legal definition of the San Francisco Bay-
Sacramento-San Joaquin River Delta, as delineated by section 12220 of 
the State of California's Water Code of 1969. Generally, the Delta is 
contained within a triangular area that extends south from the city of 
Sacramento to the confluence of the Stanislaus and San Joaquin Rivers 
on the southeast corner and Chipps Island in Suisun Bay at the 
southwest corner. The term ``Estuary,'' as used in this rule, refers to 
tidal waters contained in the Sacramento River and San Joaquin Rivers, 
the Delta, and the San Pablo and San Francisco Bays.
    Sacramento splittail were first described in 1854 by W.O. Ayres as 
Leuciscus macrolepidotus and by S.F. Baird and C. Girard as 
Pogonichthys inaeqilobus. Although Ayres' species description is 
accepted, the species was assigned to the genus Pogonichthys in 
recognition of the distinctive characteristics exhibited by the two 
splittail species P. ciscoides and P. macrolepidotus (Hopkirk 1973). P. 
ciscoides, endemic to Clear Lake, Lake County, California, has been 
extinct since the early 1970s. The Sacramento splittail (hereafter 
splittail) represents the only extant species in its genus.
    The splittail is a large cyprinid that can exceed 40 centimeters 
(16 inches) in length (Moyle 1976). Adults are characterized by an 
elongated body, distinct nuchal hump, and small, blunt head, usually 
with barbels at the corners of the slightly subterminal mouth. The 
enlarged dorsal lobe of the caudal fin distinguishes the splittail from 
other minnows in the Central Valley of California. Splittail are dull, 
silvery-gold on the sides and olive-gray dorsally. During spawning 
season, the pectoral, pelvic, and caudal fins are tinged with an 
orange-red color. Males develop small white nuptial tubercles on the 
head.
    Splittail are endemic to California's Central Valley, where they 
were once widely distributed (Moyle 1976). Historically, splittail were 
found as far north as Redding on the Sacramento River, as far south as 
the present-day site of Friant Dam on the San Joaquin River, and as far 
upstream as the current Oroville Dam site on the Feather River and 
Folsom Dam site on the American River (Rutter 1908). Recreational 
anglers in Sacramento reported catches of 50 or more splittail per day 
prior to damming of these rivers (Caywood 1974). The species was used 
as part of the Central Valley Native American diet (Caywood 1974).
    In recent times, dams and diversions have increasingly prevented 
upstream access to large rivers, and the species is now restricted to a 
small portion of its former range (Moyle and Yoshiyama 1992). Splittail 
enter the lower reaches of the Feather (Jones and Stokes 1993) and 
American Rivers (Charles Hanson, State Water Contractors Association, 
in litt., 1993) on occasion; however, the species now largely is 
confined to the Delta, Suisun Bay, Suisun Marsh, and Napa Marsh.
    Splittail are relatively long-lived, frequently reaching 5 to 7 
years of age. Females are highly fecund and produce over 100,000 eggs 
each year. Populations fluctuate annually depending on spawning 
success, which is highly correlated with freshwater outflow and the 
availability of shallow-water habitat with submerged vegetation 
(Daniels and Moyle 1983). Fish usually reach sexual maturity by the end 
of their second year. Some variability in the period of reproduction 
exists because older individuals reproduce first, followed by younger 
individuals (Caywood 1974). The onset of spawning is associated with 
rising temperature, and peak spawning occurs from the months of March 
through May, although records of spawning exist for late January to 
early July (Wang 1986). Spawning occurs over flooded vegetation in 
tidal freshwater and euryhaline habitats of estuarine marshes and 
sloughs and slow-moving reaches of large rivers. Larvae remain in 
shallow, weedy areas close to spawning sites and move into deeper water 
as they mature (Wang 1986).
    Splittail are benthic foragers that feed on opossum shrimp 
(Neomysis mercedis), although detrital material makes up a large 
percentage of their stomach content (Daniels and Moyle 1983). 
Earthworms, clams, insect larvae, and other invertebrates also are 
found in the diet. Predators include striped bass and other piscivores.
    Although primarily a freshwater species, the splittail can tolerate 
salinities as high as 10 to 18 parts per thousand (ppt) (Moyle 1976, 
Moyle and Yoshiyama 1992). In recent years, this fish has been found 
most often in slow-moving sections of rivers and sloughs and dead-end 
sloughs (Moyle et al. 1982, Daniels and Moyle 1983). Reports from the 
1950s, however, mention Sacramento River spawning migrations and 
catches of splittail during fast tides in Suisun Bay (Caywood 1974). 
Because they require flooded vegetation for spawning and rearing, 
splittail are frequently found in areas subject to flooding, such as 
the major flood basins distributed throughout the Sacramento and San 
Joaquin Valleys. California Department of Fish and Game (CDFG) survey 
data from the last 15 years indicate that the highest catches occurred 
in shallow areas of Suisun and Grizzly Bays.
    The decline in splittail abundance has taken place during increased 
human-induced changes to seasonal estuary hydrology and freshwater 
exports and the accompanying changes in the temporal, spatial, and 
relative ratios of water diversions. These deleterious hydrological 
effects, coupled with severe drought years, introduced aquatic species, 
and loss of shallow-water habitat to reclamation, seem to have reduced 
the species' capacity to recover from natural seasonal fluctuations in 
hydrology for which it was adapted.
    Analyses of survey data collected since 1967 (Meng 1993) by 
Service, CDFG, and University of California, Davis, biologists from 
several different studies indicate the following:
    (1) On average, splittail have declined in abundance by 62 percent 
since 1984. Percent decline varied among studies, dependent upon 
location of sampling effort. The greatest declines (over 80 percent) 
were found from studies that sampled the shallow Suisun Bay area, the 
center of the species' range. A study that began in 1980 at the lower 
Estuary, the outermost edge of splittail range, found the lowest 
percent decline (34 percent). The number of splittail young taken at 
State and Federal pumping facilities (per acre-foot of water pumped) 
has declined 64 percent since 1984;
    (2) Successful reproduction in splittail is highly correlated with 
wet years, but within these wet years, young-of-the-year taken per unit 
effort has declined steadily from a high of 12.3 in 1978 to 0.3 in 
1993;
    (3) A strong relationship exists between young-of-the-year 
abundance and outflow (i.e., river outflow into San Francisco Bay after 
water exports are removed). As outflow increases, annual abundance of 
splittail young increases. Changes in outflow explain 73 percent of the 
changes seen in splittail young abundance;
    (4) When young-of-the-year abundance is predicted using unimpaired 
outflow (i.e., river outflow without water exports removed), abundance 
is higher than expected in dry years, indicating that water exports 
affect young-of-the-year abundance in dry years. In dry years when 
river outflow is reduced, high proportions of outflow are diverted, 
resulting in lower than expected splittail young numbers;
    (5) Lower than expected numbers of splittail young persisted 
throughout the recent 6-year drought in California. This prolonged 
period of poor reproductive success may affect the stock's ability to 
recover;
    (6) Splittail are most abundant in shallow areas of Suisun and 
Grizzly Bays and are vulnerable to increased salinities. Salinities 
increase when, as a result of water exports and drought conditions, the 
entrapment zone (mixing zone at the freshwater-saltwater interface) is 
moved upstream. Concentration of splittail in shallow areas suggests 
that they are particularly vulnerable to reclamation activities, such 
as dredging and the diking and filling of wetlands; and
    (7) Splittail distribution has shifted upstream into the lower 
Sacramento River and South Delta since 1983. Ninety-one percent of the 
splittail captured in San Pablo and lower Suisun Bays from 1967 to 1993 
were taken before 1983, and 77 percent of the splittail captured in the 
lower Sacramento River and South Delta were taken after 1983. Because 
State and Federal water project pumps are located near the lower 
Sacramento River and South Delta, this upstream shift in splittail 
distribution increases splittail mortality at the pumps. In 1993, the 
number of splittail young taken at the Federal pumping facility was 
four times higher than in previous years.
    A variety of factors affects the estuarine ecosystems and has led 
to the decline of Sacramento splittail. Principal among these factors 
specific to the Estuary are the altered hydraulics and reduced outflow 
of the Delta caused by export of freshwater from the Sacramento and San 
Joaquin Rivers through State and Federal water diversion projects. 
Additional threats to this species include:
    (1) Loss at pumping plants and in-Delta diversion sites,
    (2) Loss of spawning and nursery habitat as a consequence of 
draining and diking for agriculture,
    (3) Reduction in the availability of highly productive brackish-
water habitat,
    (4) Urban and agricultural pollution,
    (5) Introduction of exotic species, and
    (6) Exacerbation of the effects of these factors as a result of 6 
years of drought.
    The causes of splittail decline in the Estuary are multiple and 
synergistically threaten this species. The individual threats include:
    (1) Reduced river outflows, primarily in the Sacramento and San 
Joaquin Rivers and their tributaries;
    (2) Loss of shallow-water habitat;
    (3) Mortality caused by diversion into State and Federal water 
projects and privately-operated agricultural in-Delta water diversions;
    (4) Human and natural perturbations of the food web;
    (5) Presence of toxic substances in the aquatic habitat (e.g., 
agricultural and industrial chemicals and heavy metals); and
    (6) Introduction of non-native species.

Previous Service Action

    The Service included the Sacramento splittail as a category 2 
candidate species for possible future listing as endangered or 
threatened in the January 6, 1989 (54 FR 554), Animal Notice of Review. 
Category 2 includes species for which information contained in Service 
files indicates that proposing to list is possibly appropriate but 
additional data is needed to support a listing proposal.
    On November 5, 1992, the Service received a petition from Mr. 
Gregory A. Thomas of the Natural Heritage Institute to add the 
splittail to the List of Endangered and Threatened Wildlife and to 
designate critical habitat for this species in the Sacramento and San 
Joaquin Rivers and those estuaries. In his letter, Mr. Thomas 
identified the following eight organizations as co-petitioners: 
American Fisheries Society, Bay Institute of San Francisco, Natural 
Heritage Institute, Planning and Conservation League, Save San 
Francisco Bay Association, Friends of the River, San Francisco 
Baykeeper, and the Sierra Club. On June 24, 1993, the Service issued a 
90-day finding, notice of which was published in the Federal Register 
on July 6, 1993 (58 FR 36184), that the petition presented substantial 
information indicating that the requested action may be warranted. The 
Service initiated a status review and analyzed available data on this 
species (Meng 1993). Additional sources of information describing the 
human factors and projects that may affect this species include expert 
testimonies presented to the California State Water Resources Control 
Board's 1987 Water Quality/Water Rights Proceeding on the San Francisco 
Bay and Sacramento-San Joaquin River Delta and 1992 Water Rights Phase 
of the Bay-Delta Estuary Proceedings. This proposal constitutes the 
final finding on the petition to list the Sacramento splittail.

Summary of Factors Affecting the Species

    Section 4 of the Endangered Species Act (16 U.S.C. 1531 et seq.) 
and regulations (50 CFR part 424) promulgated to implement the listing 
provisions of the Act set forth the procedures for adding species to 
the Federal Lists. A species may be determined to be endangered or 
threatened because of one or more of the five factors described in 
section 4(a)(1). These factors and their application to the Sacramento 
splittail (Pogonichthys macrolepidotus) are as follows:

A. The Present or Threatened Destruction, Modification, or Curtailment 
of Its Habitat or Range

    The Sacramento splittail was once widely distributed in the Central 
Valley of California from Redding to the modern-day site of Friant Dam 
near the City of Fresno. It is now restricted to western, northern, and 
southern portions of the Delta due to dams, diversions, dredging, and 
the diking and filling of historic flood basins. Within the species' 
constricted range, splittail have declined by 62 percent since 1984. 
However, the overall percentage decline over its historical range is 
much greater. Populations have fluctuated somewhat in the past, with 
most recruitment taking place in wet years. In wet years since 1976, 
however, splittail recruitment has declined consistently with catches 
per unit effort of 12.3, 8.1, 2.0, 1.3, and 0.3 for 1978, 1982, 1983, 
1986, and 1993, respectively. Splittail declines are highest (82 
percent) in the shallow-water Suisun Bay area, which is the center of 
its distribution. This may reflect the loss of productive brackish-
water habitat in Suisun and Grizzly Bays due to increased salinities 
caused by low outflows.
    Currently, Delta water diversions and exports total to about 9 
million acre-feet per year. Federal and State projects presently export 
about 6 million acre-feet per year when sufficient water is available, 
and in-Delta agricultural uses result in diversion of about 3 million 
additional acre-feet per year. Plans currently being prepared could 
potentially induce increased exports and diversions in the future. The 
Service knows of 22 major Central Valley Project, State Water Project, 
or private organization proposals that would result in increased water 
exports from the Delta, reduced water inflow to the Delta, changes in 
the timing and volume of Delta inflow, or increases in heavy metal 
contamination of the Delta. These proposed projects or actions include 
but are not limited to Central Valley Project Operations Criteria and 
Plan (including Friant Contract Renewals), Los Banos Grandes Reservoir, 
Los Vaqueros Reservoir, South Delta Water Management Program, South 
Delta Water Barriers Project, North Delta Water Management Project, 
West Delta Water Management Project, Coastal Aqueduct proposal, Delta 
Wetlands Corporation Water Storage Project, Folsom Dam Reoperation, 
Oroville Dam Reoperation, Auburn Dam, Central Valley Project contract 
renewals, the Central Valley Project and State Water Project wheeling 
purchase agreement, reactivation of the San Luis Drain, Stanislaus-
Calaveras River Basin Water Use Program, Suisun Marsh Project Phase 
Three and Four, Kern Water Bank, Arvin Edison water storage and 
exchange proposal, Federal Water Project change in diversion point, and 
State Water Project Pump additions. These projects would modify or 
destroy the habitat of this species.
    Because the Federal pumping plant has been operated at capacity for 
many years except for a few drought years, increased exports at this 
plant appear unlikely. However, the State Water Project pumping plant 
and the capacity of the State Aqueduct have considerable unused 
capacity. The California Department of Water Resources (1992) reported 
the past and projected State Water Project deliveries from Delta 
sources during the years of 1962 to 2035. In the 1980s, deliveries 
ranged from 1.5 million acre-feet to 2.8 million acre-feet. By 2010, 
deliveries of up to 4.2 million acre-feet are planned.
    Since 1983, the proportion of water exported from the Delta during 
October through March has been higher than in earlier years (Moyle et 
al. 1992). The timing of these proportionally higher exports have 
coincided with the spawning season of the splittail. Federal and State 
water diversion projects in the southern Delta export, by absolute 
volume, mostly Sacramento River water with some San Joaquin River 
water. Moreover, during periods of high export pumping and low to 
moderate river outflows, reaches of the San Joaquin River reverse 
direction and flow upstream to the pumping plants located in the 
southern Delta. The State-operated pumping plant presently exports 
water at rates up to 6,400 cubic feet per second (cfs). The State is 
considering proposals to export an additional 3,900 cfs. The Federal 
pumping plant can export water at rates up to 4,600 cfs. In addition, 
local private diverters export up to 5,000 cfs from about 1,800 
diversions scattered throughout the Delta.
    When total diversion rates are high relative to Delta outflow, and 
the lower San Joaquin River and other channels have a net upstream 
(i.e., reverse or negative) flow, out-migrating larval and juvenile 
fish of many species become disoriented. Large mortalities occur as a 
result of loss to pumps and predation by striped bass at the various 
water facilities and other diversion sites. Because data from State and 
Federal pumping facilities indicate that splittail migrate upstream to 
spawn, positive outflows are also important to transport splittail 
young downstream (Meng 1993).
    In recent years, the number of days of reversed San Joaquin River 
flow have increased (Moyle et al. 1992), particularly during the 
February-June spawning months for splittail. All size classes of 
splittail young suffer near total loss when they are entrained by the 
pumping plants and diversions in the south Delta. Few young are 
effectively salvaged at the Federal and State pumping plant screens. 
This species' embryonic, larval, and postlarval mortality rates also 
are higher when reduced outflows cause increases in salinity and 
relocation of the entrapment zone (Moyle and Yoshiyama 1992).
    Splittail are adapted for life in the entrapment zone. Estuaries 
are ecosystems where the entrapment zone and salinity levels are 
determined by the interaction of river outflow and tidal action. 
Splittail are most abundant in the shallow waters of Suisun Bay, which 
is historically associated with the entrapment zone. The young of this 
species require high zooplankton densities produced by the entrapment 
zone environment. The best survival and growth of splittail occurs when 
the entrapment zone occupies a large geographic area with extensive 
shoal regions within the euphotic zone (depths less than 4 meters). 
Fall mid-water trawl survey data collected by CDFG indicate that 76 
percent of the splittail captured from 1967 to 1992 in the Delta were 
taken in the shallow areas of Suisun and Grizzly Bays (Meng 1993).
    During periods of drought and increased water diversions, the 
entrapment zone and associated fish populations are shifted farther 
upstream in the Estuary. During years prior to 1984, the entrapment 
zone was located in Suisun Bay from October through March (except in 
months with exceptionally high outflows or during years of extreme 
drought). From April through September, the entrapment zone usually was 
found upstream in the river channels. Since 1984, with the exception of 
the record 1986 flood outflows, the entrapment zone has been located 
primarily in the river channels during the entire year because of 
drought and increased water exports and diversions. When located 
upstream, the entrapment zone is confined to deep river channels where 
the total surface area is smaller, fewer shoal areas of suitable 
spawning substrate exist, water currents are swifter and more 
turbulent, and zooplankton productivity is low. In all respects, the 
upstream river channels are much less favorable for spawning and 
rearing of splittail. Splittail declines since 1984 have been 
concurrent with an increasing amount and proportion of freshwater 
diversions that confine the entrapment zone to the narrow, deep, and 
less productive channels in the lower rivers.

B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    This factor is not known to be applicable. Some scientific 
collecting is conducted for splittail, but these activities do not 
adversely affect this species. Little or no recreational harvest of 
splittail is likely occurring because the population has dramatically 
declined, and it is not a desirable game species. No recent records of 
splittail harvest exist, probably because little or no harvest occurs, 
and the identification of this species is often confused with other 
nongame species. No other recreational or educational uses of this 
species exist that may affect its abundance.

C. Disease or Predation

    This factor is not known to be applicable. However, if the non-
native striped bass populations increase, all size classes of splittail 
could be under greater threat of predation. An effort by CDFG is under 
way to compensate for striped bass population mortalities caused by 
water export projects. The 1991 striped bass stock was low relative to 
the population in the 1960s. Previously, the striped bass compensation 
program annually released 1 to 2 million juvenile, hatchery-reared 
striped bass in the Estuary in an effort to rebuild the population. 
However, for the last 2 years, the Director of CDFG has foregone 
release of striped bass because of the potential harm they would cause 
to the federally-threatened Sacramento River winter-run chinook salmon 
and delta smelt.

D. The Inadequacy of Existing Regulatory Mechanisms

    Regulatory mechanisms currently in effect do not provide adequate 
protection for the splittail or its habitat. This species is not listed 
by the State of California.
    Suisun Bay is the best known nursery habitat for reproduction and 
larval survival of splittail, but the habitat has been deleteriously 
altered by higher salinities in the spring. These higher salinities are 
caused by a large number of freshwater diversions that allow seawater 
to intrude farther upstream. At present, there are relatively few 
periods when freshwater outflow volumes through the Delta and Suisun 
Bay of any significance are mandated for wildlife or fisheries. State 
and Federal agencies had planned to increase 1991 and 1992 water 
supplies for out-of-stream uses at the expense of environmental 
protection of estuarine fish and wildlife resources in the fifth and 
potentially sixth years of drought (Morat 1991). Because of 
significantly higher than normal precipitation and subsequent higher 
instream flows after March 1991, a State agency request for relaxation 
of Delta water quality standards was withdrawn. Should a California 
drought return, water quality relaxation action likely will be 
requested again to favor out-of-stream water use over the need to 
protect aquatic habitats for fish and wildlife.
    Present regulatory processes do not ensure that water inflows to 
Suisun Bay and the western Estuary will be adequate to maintain the 
entrapment zone near or in Suisun Bay to benefit splittail. The 
California State Water Resources Control Board (Board) has the 
authority to condition or require changes in the amount of water inflow 
and the amount of water exported or diverted from the Delta. In 
testimony given before the Board's Water Quality/Water Rights Hearings 
in 1987, a Service biologist expressed concern for several Delta 
species including splittail (Lorentzen 1987). The Board did not take 
regulatory or legal action to protect this fish or its habitat during 
the four following years. On May 1, 1991, the Board adopted the Water 
Quality Control Plan for Salinity for the San Francisco Bay-Sacramento-
San Joaquin Delta Estuary (1991 Bay/Delta Plan). On September 3, 1991, 
under provisions of the Clean Water Act, the Environmental Protection 
Agency (EPA) disapproved certain water quality standards for the 
Board's failure to adopt criteria to protect estuarine habitat. In 
1993, EPA began the process of formulating replacement standards for 
those portions of the 1991 Bay/Delta Plan that were disapproved. In 
January 1992, the Governor of California announced a new water policy 
that included a directive to the Board to establish ``interim 
measures'' to reverse the decline of fishes in the Bay and Delta. 
Accordingly, the Board released an interim water quality plan (Draft 
Decision 1630) in December 1992 that immediately was suspended by the 
Governor.
    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 is published in this same Federal Register 
separate part; however, enforcement of these standards may be 
difficult. The Service is aware that the salinity standards currently 
in effect (Water Right Decision 1485) are inconsistently implemented 
and frequently violated. Institutional guarantees of compliance have 
been lacking in the past and are needed in the future before existing 
mechanisms can contribute to the protection of this species.
    The Service currently is analyzing the potential effects on the 
splittail and other fish and wildlife resources in California as a 
result of recent enactment of the Central Valley Project Improvement 
Act (Pub. L. 102-575). Two of the stated purposes of this act are to: 
``Protect, restore, and enhance fish, wildlife, and associated habitats 
in the Central Valley and Trinity River basins of California'' and ``to 
contribute to the State of California's interim and long-term efforts 
to protect the San Francisco Bay-Sacramento-San Joaquin Delta 
Estuary.'' Section 3406(b)(2) dedicates 800,000 acre-feet of Central 
Valley Project water annually for various purposes, including the 
benefit of federally listed species. Although the Service is reasonably 
certain that the splittail will realize some benefit from 
implementation of the Central Valley Project Improvement Act, the 
magnitude and timeliness of these protections may be inadequate to 
prevent further decline of splittail.
    Protective measures currently being implemented to benefit the 
delta smelt will beneficially affect the splittail by restricting 
pumping under certain conditions. However, the ecological requirements 
of each species differ, especially with respect to timing of important 
developmental stages and habitat use. Splittail need flooded lowland 
habitat for spawning and are particularly vulnerable to disturbance or 
destruction of marshy habitat. Therefore, the protections afforded the 
delta smelt, listed as threatened in 1993 under the Endangered Species 
Act, will not be sufficient to prevent further decline of the 
splittail. For the reasons stated above, the Service considers the 
existing regulatory mechanisms inadequate to ensure the long-term 
existence of the Sacramento splittail.

E. Other natural or manmade factors affecting its continued existence

    Splittail are vulnerable to extinction from stochastic events 
because of the consistent decline in population indices and severely 
constricted ranges and distribution.
    Poor water quality also may adversely affect splittail, either 
through direct exposure to toxins or depletion of zooplankton or 
invertebrate food sources. All major rivers that are tributary to the 
Estuary are exposed to large volumes of agricultural and industrial 
chemicals that are applied in the Central Valley watershed (Nichols et 
al. 1986). Agricultural chemicals and their residues, as well as 
chemicals originating in urban runoff, find their way into the rivers 
and Estuary. Approximately 10 percent of the total pesticide use in the 
United States occurs in the Sacramento and San Joaquin River 
watersheds, primarily on orchards, alfalfa, and rice during the months 
of January to June of each year (Jewel Bennett, U.S. Fish and Wildlife 
Service, in litt., 1993). Recently, high concentrations of 
organophosphate and carbamate pesticides from agricultural uses have 
been documented entering the Estuary. These pesticides are acutely 
toxic to zooplankton and fishes as far west as Martinez in Suisun Bay 
and as far south as Vernalis on the San Joaquin River (Bennett, in 
litt., 1993). The periods of pesticide use coincide with the timing of 
migration, spawning, and early development of splittail. During 
rainfall runoff events, acutely toxic pulses of pesticides move down 
the rivers and through the Estuary with remarkable persistence and 
relatively little dilution.
    Toxicology studies of rice field irrigation drain water of the 
Colusa Basin Drainage Canal have documented significant toxicity of 
drain water to striped bass embryos and larvae, Oryzias latipes larvae 
(in the Cyprinodontidae family), and the opossum shrimp, which is the 
major food organism of striped bass larvae and juveniles (Bailey et al. 
1991). This drainage canal flows into the Sacramento River just north 
of the City of Sacramento. The majority of drain water samples 
collected during April and May 1990 were acutely toxic to striped bass 
larvae (96 hour exposures); this was the third consecutive year that 
the Colusa Basin rice irrigation drain water was acutely toxic (Bailey 
et al. 1991). Splittail may be similarly affected by agricultural and 
industrial chemical run-off.
    Some heavy metal contaminants have been released into the Estuary 
from industrial and mining enterprises. While the effects of these 
contaminating compounds on splittail larvae and their zooplankton food 
resources are not well known, the compounds could adversely affect 
survival. In addition, increases in urban development in the Sacramento 
Valley will continue to result in concurrent increases in urban runoff. 
Selenium has been found in aquatic organisms (Saiki and Lowe 1987) and 
fish species in the San Joaquin River watershed (Nakamoto and Hassler 
1992). Selenium has been shown to cause developmental defects in and 
mortality of fish species (Hermanutz 1992).
    In recent years, untreated discharges of ship ballast water has 
introduced exotic aquatic species to the Estuary ecosystem (Carlton et 
al. 1990). Several exotic species may adversely affect the splittail. 
An asian clam (Potamocorbula amurensis), introduced as veliger larvae 
in 1986, was first discovered in Suisun Bay during October 1986. By 
June 1987, the Asian clam was widespread in Suisun, San Pablo, and San 
Francisco Bays irrespective of salinity, water depth, and sediment type 
at densities greater than 10,000 individuals per square meter. Asian 
clam densities declined to 4,000 individuals per square meter as the 
population aged during the year (Carlton et al. 1990). Persistently low 
river outflow and concomitant elevated salinity levels may have 
contributed to this species' population explosion (Carlton et al. 
1990). The Asian clam could potentially play an important role in 
affecting the phytoplankton dynamics in the Estuary. The clam may have 
an effect on higher trophic levels by decreasing phytoplankton biomass.
    Historically, Eurytemora affinis, the native euryhaline copepod, 
has been the most important food for larval fishes in the Estuary. 
Three non-native species of euryhaline copepods (Sinocalanus doerrii, 
Pseudodiaptomus forbesi, and Pseudodiaptomus marinus) became 
established in the Delta between 1978 and 1987 (Carlton et al. 1990), 
while E. affinis populations have declined since 1980. It is not known 
if the exotic species have displaced E. affinis or whether changes in 
the estuarine ecosystem now favor S. doerrii and the two 
Pseudodiaptomus species (Moyle et al. 1989). S. doerrii is difficult 
for larval fishes to catch because of its fast swimming and effective 
escape response (Meng and Orsi 1991). Reduced feeding efficiency and 
ingestion rates weaken and slow the growth of splittail young and make 
them more vulnerable to starvation or predation.
    The Service has carefully assessed the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by this species in determining to propose this 
rule. Sacramento splittail have declined by 62 percent over the last 15 
years. This species has been extirpated from portions of its range. In 
the Estuary during the past 2 decades, the entrapment zone, associated 
with the important nurseries for splittail, has been more frequently 
shifted upstream to a confined area of greater depth as a result of 
drought conditions, water management schedules, and the continual and 
increasing demand for water exports and diversions. These factors will 
continue to adversely affect all life stages of splittail.
    Threatened status is proposed for the Sacramento splittail because 
of several factors. The population has declined by 62 percent within 15 
years. The historical and current range of the species is constricted. 
Changes in water salinity and the reverse flow of water has shifted the 
distribution of individuals upstream and has caused the fish to be 
vulnerable to State and Federal pumping plants. The death of these fish 
due to pumping continues at present and is likely to continue in the 
future. Water exports also threaten the quality and quantity of habitat 
at present and for the future. Because Sacramento splittail are long-
lived, their decline has been gradual, and extinction is not imminent, 
listing the splittail as endangered would not be appropriate. Although 
this species is not in imminent danger of extinction at this time, it 
is likely to become endangered in the foreseeable future.
    Therefore, based on the evaluation of all available information on 
abundance, present distribution, and threats to this species, the 
Service has determined that proposing to list the Sacramento splittail 
as threatened is appropriate at this time. Critical habitat is not 
determinable for reasons discussed in the ``Critical Habitat'' section 
of this rule.

Critical Habitat

    Section 4(a)(3) of the Act requires that, to the maximum extent 
prudent and determinable, the Secretary propose critical habitat 
concurrently with proposing a species to be endangered or threatened. 
The Service finds that designation of critical habitat for the 
Sacramento splittail is not determinable at this time. Regulations at 
50 CFR 424.12(a)(2) state that critical habitat is not determinable if 
information sufficient to perform required analyses of the impacts of 
the designation is lacking or if the biological needs of the species 
are not sufficiently known to permit identification of an area of 
critical habitat. The Service's efforts to gather information on the 
potential benefits of designating critical habitat for splittail may 
lead to the conclusion that designation of critical habitat is not 
prudent. Regulations at 50 CFR 424.12(a)(1) state that a designation of 
critical habitat is not prudent when the species is threatened by 
taking or other human activity, and identification of critical habitat 
can be expected to increase the degree of such threat to the species, 
or when such designation would not be beneficial to the species.

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 insure 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.
    Federal actions that may affect the splittail 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 
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 published in this same 
Federal Register separate part proposed replacement standards for those 
portions of the State's salinity standards that were disapproved.
    Under section 4 of the Act, listing the splittail will provide 
additional impetus for the development of a recovery plan to bring 
together Federal, State, and private efforts to develop conservation 
strategies for this species. The Service has convened the Delta Native 
Fishes Recovery Team to prepare a recovery plan for declining native 
fishes in the Estuary. The recovery plan will develop a framework for 
agencies 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 splittail and other fishes native to the Estuary 
ecosystem also will be described in this plan.
    The Act and its implementing regulations found at 50 CFR 17.31 set 
forth a series of general prohibitions and exceptions that apply to all 
threatened wildlife not covered by a special rule. These prohibitions, 
in part, would make it illegal for any person subject to the 
jurisdiction of the United States to take (including harass, harm, 
pursue, hunt, shoot, wound, kill, trap, capture, collect, or attempt 
any such conduct), import or export, transport in interstate or foreign 
commerce in the course of commercial activity, or sell or offer for 
sale in interstate or foreign commerce any such species. It also is 
illegal to possess, sell, deliver, carry, transport, or ship any such 
wildlife that has been taken illegally. Certain exceptions apply to 
agents of the Service and State conservation agencies.
    Permits may be issued to carry out otherwise prohibited activities 
involving endangered or threatened wildlife species under certain 
circumstances. Regulations governing permits are at 50 CFR 17.22 and 
17.23. Permits for threatened species are available for scientific 
purposes, to enhance the propagation or survival of the species, and 
for incidental take in connection with otherwise lawful activities. In 
some instances, permits may be issued during a specified period of time 
to relieve undue economic hardship that would be suffered if such 
relief were not available. For threatened species, permits are lawful 
for zoological exhibition, educational purposes, or special functions 
consistent with the purposes of the Act. Further information regarding 
regulations and requirements for permits may be obtained from the U.S. 
Fish and Wildlife Service, Ecological Services, Permits Branch, 911 NE. 
11th Avenue, Portland, Oregon 97232-4181 (503/231-6241; FAX 503/231-
6243).

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 
particularly are sought concerning:
    (1) Biological, commercial trade, or other relevant data concerning 
any threat (or lack thereof) to this species;
    (2) The location and status of any additional populations of this 
species and the reasons why any habitat should or should not be 
determined to be critical habitat as provided by section 4 of the Act. 
Biological information that would be useful in determining whether to 
designate critical habitat includes descriptions and locations of 
spawning habitat and life history information on behavior and 
ecological needs;
    (3) Additional information concerning the range, distribution, and 
population size of this species; and
    (4) Current or planned activities in the subject area and their 
possible impacts on this species.
    Any final decision on this proposal will take into consideration 
the comments and any additional information received by the Service, 
and such communications may lead to final regulations that differ from 
this proposal.
    The Act provides for a public hearing on this proposal, if 
requested. Requests must be received within 45 days of the date of 
publication of the proposal. Such requests must be made in writing and 
addressed to the Acting Field Supervisor, Sacramento Field Office (see 
ADDRESSES section).

National Environmental Policy Act

    The Service has determined that an Environmental Assessment, 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 Endangered Species Act of 1973, as 
amended. A notice outlining the Service's reasons for this 
determination was published in the Federal Register on October 25, 1983 
(48 FR 49244).

References Cited

Bailey, H.C., D.J. Ostrach, and D.E. Hinton. 1991. Effect of rice 
irrigation water in Colusa Basin Drain on fertilization success and 
embryonic development in striped bass. Contract No. 9-169-250-0 
Draft Report to California State Water Resources Control Board. 31 
pp.
California Department of Water Resources. 1992. Data and 
computations used to determine 1993 water charges. Bulletin 132-92, 
Appendix B. California Department of Water Resources, Sacramento, 
California. 136 pp.
Carlton, J.T., J.K. Thompson, L.E. Schemel, and F.H. Nichols. 1990. 
Remarkable invasion of San Francisco Bay (California, USA) by the 
asian clam Potamocorbula amurensis. I. Introduction and dispersal. 
Mar. Ecol. Prog. Ser. 66:81-94.
Caywood, M.L. 1974. Contributions to the life history of the 
splittail Pogonichthys macrolepidotus (Ayres). M.S. Thesis. 
California State University, Sacramento.
Daniels, R.A., and P.B. Moyle. 1983. Life history of the splittail 
(Cyprinidae: Pogonichthys macrolepidotus) in the Sacramento-San 
Joaquin estuary. Fish. Bull. 84:105-117.
Hermanutz, R.O. 1992. Malformation of the fathead minnow (Pimephales 
promelas) in an ecosystem with elevated selenium concentrations. 
Bull. Environmental Contamination and Toxicology Report 49:290-294.
Hopkirk, J.D. 1973. Endemism in the fishes of the Clear Lake region 
of central California. Univ. Calif. Publ. Zool. 96.
Jones and Stokes Assoc., Inc. 1993. Sutter Bypass fisheries 
technical memorandum II: Potential entrapment of juvenile chinook 
salmon in the proposed gravel mining pond. May 27, 1993. (JSA 91-
272). Sacramento, California. Prepared for Teichert Aggregates, 
Sacramento, California. 31 pp + Appendix.
Lorentzen, E.M. 1987. U.S. Fish and Wildlife Service testimony in 
the matter of State Water Resources Control Board water quality/
water rights proceeding on the San Francisco Bay and Sacramento-San 
Joaquin River Delta, September 8-10, 1987. U.S. Fish Wildl. Serv. 
Exhibits 17-24. 11 pp.
Meng, L. 1993. Status of Sacramento splittail and longfin smelt. 
Report submitted to U.S. Fish and Wildlife Service, August 1993.
Meng, L., and J.J. Orsi. 1991. Selective predation by larval striped 
bass on native and introduced copepods. Trans. Am. Fish. Soc. 
120:187-192.
Morat, R.J. 1991. U.S. Fish and Wildlife Service testimony in the 
matter of State Water Resources Control Board Public Hearing and 
Board Meeting on consideration of drought-related emergency water 
rights order and related actions in response to a request for a 
hearing from the Department of Water Resources, March 15, 1991. U.S. 
Fish Wildl. Serv. Exhibit 1. 3 pp.
Moyle, P.B. 1976. Inland Fishes of California. University of 
California Press, Berkeley, California. 405 pp.
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.
Moyle, P.B., J.J. Smith, R.A. Daniels, and D.M. Baltz. 1982. 
Distribution and ecology of stream fishes of the Sacramento-San 
Joaquin Drainage System, California: A review. Univ. Calif. Publ. 
Zool. 115:225-256.
Moyle, P.B., J.E. Williams, and E.D. Wikramanayake. 1989. Fish 
species of special concern of California. Final report prepared for 
State of California, Department of Fish and Game, Inland Fisheries 
Division, Rancho Cordova, California. 222 pp.
Moyle, P.B., and R.M. Yoshiyama. 1992. Fishes, aquatic diversity 
management areas, and endangered species: A plan to protect 
California's native aquatic biota. Draft report prepared for 
California Policy Seminar, Univ. of Calif., Berkeley, California. 
July, 1992. 196 pp.
Nakamoto, R.J. and T. Hassler. 1992. Selenium and other trace 
elements in bluegills from agricultural return flows in the San 
Joaquin Valley, CA. Archives of Environmental Contamination and 
Toxicology 22:88-98.
Nichols, F.H., J.E. Cloern, S.N. Luoma, and D.H. Peterson. 1986. The 
modification of an estuary. Science 231:567-573.
Rutter, C. 1908. The fishes of the Sacramento-San Joaquin basin, 
with a study of their distribution and variation. U.S. Bur. Fish. 
Bull. 27:103-152.
Saiki, M.K., and T.P. Lowe. 1987. Selenium in aquatic organisms from 
subsurface agricultural drainage water, San Joaquin Valley, 
California. Arch. Environ. Contam. Toxicol. 16:657-670.
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.

Authors

    The authors of this rule are Dr. Lesa Meng and 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, and 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.

    2. Section 17.11(h) is amended by adding the following, in 
alphabetical order under FISHES, to the List of Endangered and 
Threatened Wildlife to read as follows:


Sec. 17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                    Species                                            Vertebrate population                                                            
-----------------------------------------------     Historic range      where endangered or     Status      When listed      Critical      Special rules
      Common name           Scientific name                                  threatened                                       habitat                   
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                        
                                                                      * * * * * * *                                                                     
Fishes:                                                                                                                                                 
                                                                                                                                                        
                                                                      * * * * * * *                                                                     
    Splittail,          Pogonichthys            U.S.A. (CA)..........  Entire...............  T           ..............              NA              NA
     Sacramento.         macrolepidotus.                                                                                                                
                                                                                                                                                        
                                                                      * * * * * * *                                                                     
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Dated: December 21, 1993.
Richard N. Smith,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 94-91 Filed 1-5-94; 8:45 am]
BILLING CODE 4310-55-P