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

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