The ecology, behavior, and conservation of the tidewater goby, Eucyclogobius newberryi

Understanding the ecology and behavior of endangered species, such as the tidewater goby, Eucyclogobius newberryi, is important for identifying problems and formulating solutions for species recovery. The tidewater goby forms isolated populations in California's coastal lagoons, creeks, and marshes. Rapid declines in the number of populations led to its listing as an endangered species in 1994. This benthic fish prefers stillwater habitats and feeds on small invertebrates. It is an annual species with an extended breeding season. Fish are larger in marsh habitats than in lagoon or creek habitats. The male digs a spawning burrow, preferably in sand, where he provides care for a single clutch. The tidewater goby is sex-role reversed: females compete more intensely than males for access to mates. The tidewater goby is a species at risk, in part due to narrow habitat preferences, isolation of populations, short lifespan, lack of marine dispersal, and vulnerability to introduced predatory fishes. Attributes that favor its recovery include euryhaline tolerances, rapid reproductive rate, its potential for opportunistic feeding, and the possibility of natural recolonization under certain circumstances. Potential conservation measures include protecting coastal marshes that adjoin creeks and lagoons, maintaining natural hydrologic regimes, preventing artificial breaching of the sandbar at the estuary's mouth, and preventing introductions of predatory fishes. Captive breeding and reintroduction of tidewater gobies are potential tools for recovery, provided that underlying problems of habitat availability and suitability and issues of genetic integrity and disease transmission are addressed. Further research into the tidewater goby's utilization of marsh habitats, dispersal mechanisms, response to artificial breaching events, and metapopulation genetics would provide additional information for management.