Draft Recovery Plan For the Tidewater Goby (Eucyclogobius newberryi) (October 2004) Pacific Region U. S. Fish and Wildlife Service Portland, Oregon Approved: XXXXXXXXXXXXXXXXXXXXXXXXXXXX Manager, California/Nevada Operations Office Region 1, U.S. Fish and Wildlife Service Date: _______________________________________ DISCLAIMER Recovery plans delineate reasonable actions that are believed to be required to recover and/or protect listed species. We, the U.S. Fish and Wildlife Service, publish recovery plans, sometimes preparing them with the assistance of recovery teams, contractors, State agencies, and others. Objectives will be attained and any necessary funds made available subject to budgetary and other constraints affecting the parties involved, as well as the need to address other priorities. Recovery plans do not necessarily represent the views nor the official positions or approval of any individuals or agencies involved in the plan formulation, other than our own. They represent our official position only after they have been signed by the Regional Director, Director, or California/Nevada Operations Manager as approved. Approved Recovery plans are subject to modification as dictated by new findings, changes in species status, and the completion of recovery tasks. Literature citation should read as follows: U.S. Fish and Wildlife Service. 2004. Draft Recovery Plan for the Tidewater Goby (Eucyclogobius newberryi). U.S. Fish and Wildlife Service, Portland, Oregon. vi + 163 pp. An electronic version of this recovery plan will also be made available at http://www.r1.fws.gov/ecoservices/endangered/recovery/plans.html and http://endangered.fws.gov/recovery/index.html. i ACKNOWLEDGMENTS Primary Authors Chris Dellith of the Ventura Fish and Wildlife Office, U.S. Fish and Wildlife Service, Ventura, California served as the Recovery Team Manager and prepared this draft recovery plan, with assistance from Bill McIver of the Ventura Fish and Wildlife Office. Recovery plan preparation was supervised and edited by Diane Noda, Carl Benz, and Mike McCrary of the Ventura Fish and Wildlife Office. Each member of the tidewater goby recovery team contributed valuable information and assistance. In particular, we gratefully acknowledge the efforts of Dr. Camm Swift, Dr. Kevin Lafferty, and Dr. David Jacobs, for being generous with their technical assistance and time throughout the development of this recovery plan. We thank them also for their thorough editorial review. Drawings of Eucyclogobius newberryi are reproduced by permission of Camm Swift, from Swift et al. (1989). The following individuals contributed significant information/assistance during recovery plan development (tidewater goby recovery team members are italicized): Ed Ballard David Jacobs Larry Williamson Roger Bloom Kevin Lafferty Jill Terp Ray Bosch Bill McIver Mark Helvey Diane Elam Jack Malone Rick Farris Bridget Fahey Mike Nepstad Lilian Carswell Darren Fong Carl Page Kurt Roblek Nancy Francine Ramona Swenson Grant Canterbury Greg Goldsmith Camm Swift David Anderson Gjon Hazard Anna Toline Bob Hoffman Christopher White ii EXECUTIVE SUMMARY Current Species Status: The tidewater goby (Eucyclogobius newberryi) is listed as endangered. It is a small fish that inhabits coastal brackish water habitats entirely within California, ranging 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 known to have historically inhabited at least 124 localities. Presently 28 (23 percent) of the 124 documented localities are considered extirpated and 55 to 70 (45 to 55 percent) of the localities are naturally so small or have been degraded over time that long-term persistence is uncertain. Habitat Requirements: Tidewater gobies are uniquely adapted to coastal lagoons and the uppermost brackish zone of larger estuaries, rarely invading marine or freshwater habitats. The species is typically found in water less than 1 meter (3.3 feet) deep and salinities of less than 12 parts per thousand. Principal threats to the tidewater goby include loss and modification of habitat, water diversions, predatory and competitive introduced fish species, habitat channelization, and degraded water quality. Recovery Objective: Downlist to threatened status, then delist. The primary objective of this recovery plan is to eliminate the threats to and improve the population status of the tidewater goby sufficiently to warrant reclassification (from endangered to threatened status) or delisting. Recovery Priority Number: The tidewater goby has a recovery priority number of 7C (on a scale of 1 to 18), per criteria published in the Federal Register (U.S. Fish and Wildlife Service 1983). This number indicates a species with moderate threats and a high potential for recovery. The letter C indicates that there is some degree of conflict between the species’ recovery efforts and economic development. Recovery Criteria: We subdivide the geographic distribution of the tidewater goby into 6 recovery units, encompassing a total of 26 Sub-Units defined according to genetic differentiation and geomorphology. The tidewater goby may be considered for downlisting when: 1) An analysis based on scientifically credible monitoring over a 10-year period projects a 75 percent chance of all Sub-Units within each recovery unit persisting for a minimum of 100 years. This projection would incorporate a metapopulation viability analysis using a complex suite of information. A partial list of information needed for the metapopulation viability analysis includes: presence/absence data; population estimates; observed rates of extirpation and natural recolonization; results of introduction efforts to new localities and reintroduction to sites of known or suspected extirpation; and the relationships between climate variation and extinction and recolonization probabilities. This projection will also require incorporating information on new threats at the time of downlisting, such as any new exotic predator introductions that may have occurred. 2) All goby metapopulations are managed so that threats from habitat destruction and alteration (e.g., coastal development, upstream diversion, channelization of rivers and streams, discharge of iii agriculture and sewage effluents), introduced predators (e.g., centrarchid fishes), and competition with introduced species (e.g., yellowfin and chameleon gobies) are reduced to the extent that each metapopulation is not at risk of extirpation. The tidewater goby may be considered for delisting when downlisting criteria have been met and: 1) An analysis based on scientifically credible monitoring over a 10-year period projects a 95 percent chance of all Sub-Units within each recovery unit persisting for a minimum of 100 years. This projection would incorporate a metapopulation viability analysis using a complex suite of information. A partial list of information needed for the metapopulation viability analysis includes: presence/absence data; population estimates; observed rates of extirpation and natural recolonization; results of introduction efforts to new localities and reintroduction to sites of known or suspected extirpation; and the relationships between climate variation and extinction and recolonization probabilities. This projection will also require incorporating information on new threats at the time of delisting, such as any new exotic predator introductions that may have occurred. Actions Needed: 1. Monitor, protect and enhance currently occupied tidewater goby habitat. 2. Conduct biological research to enhance the ability to integrate land use practices with tidewater goby recovery and revise recovery tasks as pertinent new information becomes available. 3. Evaluate and implement translocation where appropriate. 4. Increase public awareness about tidewater gobies. Estimated Total Cost of Recovery: $1,505,000 over the next 10 years, with costs yet to be determined for securing and protecting coastal wetlands and for assurance of successful establishment of additional populations of tidewater goby. Funding opportunities and management will need to be developed between landowners, regulatory agencies, nonprofit organizations, and other interested parties. Date of Recovery: If recovery criteria are met, reclassification to threatened status could be initiated in 2015. iv TABLE OF CONTENTS I. BACKGROUND........................................................................................................................ 1 A. Brief Overview ...................................................................................................................... 1 B. Description and Taxonomy....................................................................................................1 C. Distribution and Habitat......................................................................................................... 5 D. Critical Habitat .................................................................................................................... 10 E. Life History .......................................................................................................................... 10 F. Abundance and Trends......................................................................................................... 12 G. Reason for Decline and Current Threats ............................................................................. 13 1. The present or threatened destruction,