Tidewater Goby

Eucyclogobius newberryi berryi

Description

The tidewater goby is a small fish, rarely exceeding 2 in (5.1 cm) in length. It has large pectoral fins and a ventral suckerlike disk formed by the complete fusion of the pelvic fins.

Behavior

Peak nesting activities commence in late April through early May, when male gobies dig a vertical nesting burrow 4-8 in (10.2-20.4 cm) deep in clean, coarse sand. Suitable water temperatures for nesting are 75.6-79.6°F. (24.2-26.4°C) with salinity of five to 10 parts per thousand. Male gobies remain in the burrows to guard the eggs, which are hung from the ceiling and walls of the burrow until hatching. Larval gobies are found midwater around vegetation until they become benthic.

Habitat

The tidewater goby is almost unique among fishes along the Pacific coast of the United States in its restriction to waters with low salinity. All populations are generally found at the upper end of lagoons in salinity less than 10 parts per thousand, although gobies have been collected and reared in slightly higher salinity.

The tidewater goby occurs in loose aggregations of a few to several hundred individuals on the substrate in shallow water less than 3 ft (91 cm) deep, although they have been observed in depths up to 7.6 ft (2.3 m).

Distribution

Historically, the tidewater goby occurred in at least 87 of California's coastal lagoons. Since 1900 it has disappeared from approximately 50% of formerly occupied lagoons. The tidewater goby is discontinuously distributed throughout California, ranging from Tillas Slough (mouth of the Smith River) in Del Norte County south to Agua Hedionda Lagoon in San Diego County. Areas of precipitous coastlines that preclude the formation of lagoons at stream mouths have created three gaps in the distribution of the goby. Gobies are apparently absent from the Humboldt Bay and Ten Mile River; Point Arena and Salmon Creek; and Monterey Bay and Arroyo del Oso.

Threats

The major factor adversely affecting the tidewater goby is coastal development projects that have caused a loss of coastal saltmarsh habitat. Coastal marsh habitats have been drained and reclaimed for residential and industrial developments. Waterways have been dredged for navigation and harbors, resulting in permanent and direct loss of wetland habitats, as well as indirect losses due to changes in salinity. Coastal road construction projects have severed the connection between marshes and the ocean, resulting in unnatural temperature and salinity profiles that the tidewater goby cannot tolerate.

Furthermore, upstream water diversions adversely affect the tidewater goby by altering downstream flows, thereby diminishing the extent of marsh habitats that occurred historically at the mouths of most rivers and creeks in California. Alterations of flows upstream of coastal lagoons have already changed the distribution of downstream salinity regimes. Since the tidewater goby has relatively narrow salinity tolerances, changes in salinity distribution due to upstream water diversions may adversely affect both the size and distribution of goby populations.

Conservation and Recovery

No critical habitat or recovery plan has been designated. The Santa Ynez estuary, which is owned by the U.S. Air Force, is subject to the conservation mandate and prohibitions against jeopardy.

Roughly 10% of the coastal lagoons presently containing tidewater goby are under Federal ownership. Over 40% are entirely or partly owned and managed by the state of California. The remainder is privately owned.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
http://pacific.fws.gov/

U.S. Fish and Wildlife Service
Ventura Field Office
2493 Portola Road, Suite B
Ventura, California 93003-7726
Telephone: 805-644-1766

Reference

U.S. Fish and Wildlife Service. 4 February 1994. "Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for the Tide-water Goby." Federal Register 59 (24): 5494-5498.