Endangered and Threatened Wildlife and Plants; Reopening of the Comment Period on the Proposed Rule To Remove the Northern Populations of the Tidewater Goby From the List of Endangered and Threatened Wildlife

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Proposed rule; Notice of reopening of comment period.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), pursuant to the Endangered Species Act of 1973, as amended (Act), provide notice of the reopening of the comment period for the proposed delisting of the northern populations of the tidewater goby (Eucyclogobius newberryi) from the list of endangered and threatened wildlife. The comment period has been reopened in response to new information regarding tidewater goby marine dispersal. This proposal would remove the northern populations of the Tidewater goby from protection under the Act.

DATES:

Comments from all interested parties must be received by March 31, 2000.

ADDRESSES:

Send written comments and other materials concerning this proposal to Ms. Diane Noda, Field Supervisor, Ventura Fish and Wildlife Office, 2493 Portola Road, Suite B, Ventura, California 93003. You may inspect comments and materials received, by appointment, during normal business hours at the above address.

FOR FURTHER INFORMATION CONTACT:

Carl Benz at the above address; telephone 805/644-1766; facsimile 805/644-3958.

SUPPLEMENTARY INFORMATION:

Background

The tidewater goby was first described in 1857 by Girard as Gobius newberryi. Gill (1862) erected the genus Eucyclogobius for this distinctive species. The majority of scientists have accepted this classification (Bailey et al. 1970; Miller and Lea 1972; Hubbs et al. 1979; Robins et al. 1991; Eschmeyer et al. 1983). No other species have been described in this genus. A few older works and Ginsburg (1945) placed the tidewater goby and the eight related eastern Pacific species into the genus Lepidogobius. This classification includes the currently recognized genera Lepidogobius, Clevelandia, Ilypnus, Quietula, and Eucyclogobius. Birdsong et al. (1988) coined the informal Chasmichthys species group, recognizing the phyletic relationship of the eastern Pacific group with species in the northwestern Pacific.

Crabtree's (1985) allozyme work on tidewater gobies from 12 localities throughout the range showed fixed allelic differences at the extreme northern (Lake Earl, Humboldt Bay) and southern (Canada de Agua Caliente, Winchester Canyon, and San Onofre Lagoon) ends of the range. The northern and southern populations are genetically distinct from each other and from the central populations sampled. The more centrally distributed populations are relatively similar to each other (Brush Creek, Estero Americano, Corcoran Lagoon, Arroyo de Corral, Morro Bay, Santa Ynez River, and Jalama Creek). Crabtree's results indicated that there is a low level of gene flow (movement of individuals) between the populations sampled in the northern, central, and southern parts of the range. However, Lafferty et al. (in prep.) point out that Crabtree's sites were widely distributed geographically, and may not be indicative of gene flow on more local levels.

Recently, David Jacobs (University of California, Los Angeles, Department of Organismic Biology, Ecology and Evolution, in litt. 1998) initiated an analysis of mitochondrial genetic material from tidewater goby populations ranging from Humboldt to San Diego counties. Preliminary results indicate the southern goby population separated from other goby populations along the coast long ago. This southernmost population probably began diverging from the remainder of the gobies in excess of 100,000 years ago. Furthermore, gobies from the Point Conception area are more closely related to gobies from Humboldt County than they are to the gobies analyzed in San Diego and Orange counties.

The tidewater goby (Eucyclogobius newberryi) is a small, elongate, grey-brown fish with dusky fins not exceeding 50 millimeters (mm) (2 inches (in.)) standard length (SL). The tidewater goby is a short-lived species, apparently having an annual life cycle (Irwin and Soltz 1984; Swift et al. 1997). At the time of the listing, the species was believed to have more stringent habitat requirements and to be less likely to disperse successfully than recent research indicates (see below). These factors, coupled with the short life span of the tidewater goby, were believed to make most tidewater goby populations vulnerable to extirpation by human activities. At the time of the listing, we believed that approximately 50 percent of the documented populations had been extirpated. However, in spite of the many factors affecting coastal wetlands, recent survey data have demonstrated a less than 25 percent permanent loss of the known tidewater goby populations (Ambrose et al. 1993; Swift et al. 1994; Lafferty et al. 1996; C. Chamberlain, U.S. Fish and Wildlife Service, Arcata, California, in litt. 1997; Lafferty 1997; Swift et al. 1997).

The tidewater goby inhabits coastal brackish water habitats entirely within California. Within the range of the tidewater goby, these conditions occur in two relatively distinct situations: (1) The upper edge of tidal bays, such as Humboldt, Tomales, and San Francisco bays near the entrance of freshwater tributaries, and (2) the coastal lagoons formed at the mouths of small to large coastal rivers, streams, or seasonally wet canyons, along most of the length of California. Few well-authenticated records of this species are known from marine environments outside of enclosed coastal lagoons and estuaries (Swift et al. 1989). This may be due to the lack of collection efforts at appropriate times (i.e., following storm events or breachings when gobies are flushed from the estuaries and lagoons). Historically, the species ranged from Tillas Slough (mouth of the Smith River, Del Norte County) near the Oregon border south to Agua Hedionda Lagoon (northern San Diego County). The tidewater goby is often found in waters of relatively low salinities (around 10 parts per thousand (ppt)) in the uppermost brackish zone of larger estuaries and coastal lagoons. However, the fish can tolerate a wide range of salinities (Swift et al. 1989, 1997; Worcester 1992; K. R. Worcester, California Department of Fish and Game (CDFG), in litt. 1996; Worcester and Lea 1996), and is frequently found throughout lagoons. Tidewater gobies regularly range upstream into fresh water, and downstream into water of up to 28 ppt salinity (Worcester 1992; Swenson 1995), although specimens have been collected at salinities as high as 42 ppt (Swift et al. 1989). The species' tolerance of high salinities (up to 60 ppt for varying time periods) likely enables it to withstand the marine environment, allowing it to colonize or reestablish in lagoons and estuaries following flood events (Swift et al. 1989; K. R. Worcester, in litt. 1996; Worcester and Lea 1996; Lafferty et al. in prep.)

The life history of tidewater gobies is linked to the annual cycles of the coastal lagoons and estuaries (Swift et al. 1989, 1994; Swenson 1994, 1995). Water in estuaries, lagoons and bays is at its lowest salinity during the winter and spring as a result of precipitation and runoff. During this time, high runoffs cause the sandbars at the mouths of the lagoons to breach, allowing mixing of the relatively fresh estuarine and lagoon waters with seawater. This annual building and breaching of the sandbars is part of the normal dynamics of the systems in which the tidewater goby has evolved (Zedler 1982; Lafferty and Alstatt 1995; Heasly et al. 1997). The time of sandbar closure varies greatly between systems and years, and typically occurs from spring to late summer. Later in the year, occasional waves washing over the sandbars can introduce some sea water, but good mixing often keeps the lagoon water at a few parts per thousand salinity or less. Summer salinity in the lagoon depends upon the amount of freshwater inflow at the time of sandbar formation (Zedler 1982, Heasly et al. 1997).

Males begin digging breeding burrows 75 to 100 mm (3 to 4 in.) deep, usually in relatively unconsolidated, clean, coarse sand averaging 0.5 mm (0.02 in.) in diameter, in April or May (Swift et al. 1989; Swenson 1994, 1995). Swenson (1995) has shown that tidewater gobies prefer this substrate in the laboratory, but also found tidewater gobies digging breeding burrows in mud in the wild (Swenson 1994). Inter-burrow distances range from about 5 to 275 centimeters (cm) (2 to 110 in.) (Swenson 1995). Females lay 100 to 1000 eggs per clutch, averaging 400 eggs/clutch, with clutch size depending on the size of both the female and the male. Females can lay more than one clutch of eggs over their lifespan, with captive females spawning 6 to 12 times (Swenson 1995). Wild females may spawn less frequently due to fluctuations in food supply and other environmental conditions, but the species clearly has a high reproductive potential, enabling populations to recover quickly under suitable conditions. Male gobies remain in the burrow to guard the eggs that are attached to sand grains in the walls of the burrow. Males also spawn more than once per season (Swenson 1995), and although they can have more than one clutch in their burrow, presumably from different females (Swift et al. 1989), Swenson (1995) found that males accepted only one female per brood period. Males frequently go for at least a few weeks without feeding, and this probably contributes to a mid-summer mortality often noted in populations (Swift et al. 1989; Swenson 1994, 1995). Reproduction peaks during spring to mid-summer, late April or May to July, and can continue into November or December depending on the seasonal temperature and rainfall. Reproduction sometimes increases slightly in the fall (Swift et al. 1989; Camm Swift, Department of Biology, Loyola Marymount University, pers. comm. 1995). Reproduction takes place when temperatures are between 15 to 20 degrees Celsius (60 to 65 degrees Fahrenheit) and at salinities of 0 to 25 ppt (Swift et al. 1989; Swenson 1994, 1995). Typically, winter rains and cold weather interrupt spawning, but in some warm years reproduction may occur all year (Goldberg 1977; Wang 1984). Goldberg (1977) showed by histological analysis that females have the potential to lay eggs all year in southern California, but this rarely has been documented. Length-frequency data from southern and central California (Swift et al. 1989; Swenson 1994, 1995) and analysis of otoliths from central California populations (Swift et al. 1997) indicate that tidewater gobies are an annual species and typically live 1 year or less.

We published a proposed rule, with additional background information, to remove the northern populations of the tidewater goby from the list of endangered and threatened wildlife on June 24, 1999 (64 FR 33816). The original comment period closed on August 23, 1999. Significant new information regarding marine dispersal of tidewater gobies was brought to our attention late in the comment period, with additional information provided since the closing of that comment period. We require time to fully evaluate the information and to solicit further peer review of this proposal. We will solicit the opinions of appropriate and independent specialists regarding the data, assumptions, and supportive information presented for the proposed delisting of the tidewater goby per our Interagency Cooperative Policy for Peer Review in Endangered Species Act Activities (59 FR 34270).

Public Comments Solicited

It is our intent that any final action resulting from this proposal will be as accurate and as effective as possible. Therefore, we solicit comments or suggestions from the public, other concerned governmental agencies, the scientific community, industry, or any other interested party concerning this proposed rule. Our practice is to make comments, including names and home addresses of respondents, available for public review during regular business hours. Individual respondents may request that we withhold their home address from the rulemaking record, which we will honor to the extent allowable by law. There also may be circumstances in which we would withhold from the rulemaking record a respondent's identity, as allowable by law. If you wish us to withhold your name and/or address, you must state this prominently at the beginning of your comment. However, we will not consider anonymous comments. We will make all submissions from organizations or businesses, and from individuals identifying themselves as representatives or officials of organizations or businesses, available for public inspection in their entirety. All comments, including written and e-mail, must be received in our Ventura Fish and Wildlife Office by March 31, 2000. We particularly seek comments concerning:

(1) Biological, commercial trade, or other relevant data concerning any threat (or lack thereof) to this species;

(2) Additional information concerning the range, distribution, and population size of this species; and

(3) Current or planned activities in the range of this species and their possible impacts on this species.

The final decision on this proposal to delist the northern population of the tidewater goby will take into consideration the comments and any additional information we receive, and such communications may lead to a final regulation that differs from this proposal.

This rule does not include any collections of information that require approval by OMB under the Paperwork Reduction Act.

National Environmental Policy Act

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

References Cited

A complete list of all references cited herein is available upon request from the Ventura Fish and Wildlife Office (see ADDRESSES section).

Authors: The primary authors of this proposed rule are Grace McLaughlin and Carl Benz, Ventura Fish and Wildlife Office (805/644-1766).

Authority: The authority of this action is the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).