Recovery Plan for the Tidewater Goby (Eucyclogobius Newberryi)
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U.S. Fish & Wildlife Service Recovery Plan for the Tidewater Goby (Eucyclogobius newberryi) Cover illustration of tidewater goby reproduced by permission of Camm Swift, from Swift et. al. (1989). Recovery Plan For the Tidewater Goby (Eucyclogobius newberryi) Pacific Region U. S. Fish and Wildlife Service Portland, Oregon 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. 2005. Recovery Plan for the Tidewater Goby (Eucyclogobius newberryi). U.S. Fish and Wildlife Service, Portland, Oregon. vi + 199 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 Kevin Lafferty Rick Farris Roger Bloom Bill McIver Lilian Carswell Ray Bosch Jack Malone Kurt Roblek Diane Elam Carl Page Grant Canterbury Bridget Fahey Ramona Swenson David Anderson Darren Fong Camm Swift Jerry Smith Nancy Francine Anna Toline Natascha Miljkovic Greg Goldsmith Bill Berry Harald Ahnelt Gjon Hazard Larry Williamson Mike McCrary Bob Hoffman Jill Terp Glenn Yoshioka David Jacobs Mark Helvey 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 formerly inhabited at least 134 localities. Presently 23 (17 percent) of the 134 documented localities are considered extirpated and 55 to 70 (41 to 52 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 manage 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. 1) The tidewater goby may be considered for downlisting when: a) Specific threats to each metapopulation, such as habitat destruction and alteration (e.g., coastal development, upstream diversion, channelization of rivers and streams, discharge of agriculture and sewage effluents), introduced predators (e.g., centrarchid fishes), and competition with iii introduced species (e.g., yellowfin and chameleon gobies), have been addressed through the development and implementation of individual management plans that cumulatively cover the full range of the species. b) A metapopulation viability analysis (see Recovery Action 2.11) based on scientifically credible monitoring over a 10-year period indicates that each Recovery Unit is viable. The target for downlisting is for individual Sub-Units within each Recovery Unit to have a 75 percent or better chance of persistence for a minimum of 100 years. Specifically, the target is for at least 5 Sub-Units in the North Coast Unit, 8 Sub-Units in the Greater Bay Unit, 3 Sub-Units in the Central Coast Unit, 3 Sub-Units in the Conception Unit, 1 Sub-Unit in the Los Angeles/Ventura Unit, and 2 Sub- Units in the South Coast Unit to individually have a 75 percent chance of persisting for 100 years 2) The tidewater goby may be considered for delisting when downlisting criteria have been met and: a) A metapopulation viability analysis projects that all recovery units are viable, as in downlisting criterion 1(b) except that the target for Sub-Units is a 95 percent probability of persistence for 100 years. 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: $1,980,000 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....................................................................................................2 C. Distribution and Habitat......................................................................................................... 6 D. Critical Habitat .................................................................................................................... 12 E. Life History .......................................................................................................................... 12 F. Abundance and Trends......................................................................................................... 15 G. Reason for Decline and Current Threats ............................................................................. 16 1. The present or threatened destruction, modification, or curtailment of its habitat or range...................................................................................................................... 16 2. Overutilization for commercial, recreational, scientific, or educational purposes. ................................................................................................................................ 18 3. Disease or predation. ........................................................................................................ 18 4. The inadequacy of existing regulatory mechanisms ......................................................... 19 5. Other natural or manmade factors affecting its continued existence ..............................