Big Win for a Little Fish: Tidewater Goby Decision Would Protect California's Most Endangered Ecosystems

Many lagoons and brackish coastal environments covered as proposed critical habitat for quirky native fish

LOS ANGELES (October 28, 2011) – A small fish could have a big impact on salt water marshes, streams and lagoons along California’s coast thanks to a recent Fish & Wildlife Service proposal which would extend protections to many of these endangered ecosystems’ on behalf of the tidewater goby. The Natural Resources Defense Council petitioned to list the tidewater goby as an endangered species in 2009 and then sued the Service after their critical habitat designation left out many of the most important places for the fish to live. As a result, the Service has made important modifications, including extending protections to new areas and setting a precedent that could be important for other species with similarly transient populations.

“These are unique fish that live in a disappearing habitat,” said NRDC wildlife attorney Rebecca Riley. “The Service’s proposal will protect this California species and some of the coast’s most imperiled spots.”

Tidewater gobies are only found in small pockets along the California coastline; from Del Norte County in the north, to San Diego County in the south. The small fish is uniquely adapted to living in the brackish waters that characterize one of the Golden State’s most imperiled ecosystems -- its coastal salt water marshes and lagoons. Though sizable populations of the fish can still be found in spots, most of the salt water marshes, lagoons, and estuaries that the gobies call home have long disappeared. Approximately 90% of the state’s wetlands have been destroyed since the days of the gold rush. In the past, when drought or changing conditions killed off the goby populations in one area, tidewater gobies from a neighboring brackish area would re-colonize. This shifting of populations rarely occurs today due to the disconnected, patchy nature of their habitat. Scientists are concerned that the mercurial changes to water level and quality that are typical of brackish ecosystems makes the goby’s population fluxes vulnerable to collapse without the added habitat connectivity afforded by some of the currently unpopulated areas.

Those concerns motivated NRDC to challenge the critical habitat designation because it protected only habitat occupied at the time of their listing as an endangered species. It excluded all other habitable areas tidewater gobies are likely to need to survive in the future. As part of the settlement of the suit, the Service agreed to take another look at the issue. Their surveys found populations of the fish in three areas that they had not been found at the time of the listing, reinforcing the concerns shared by researchers and NRDC. As a result, the new proposed critical habitat designation makes three major changes on the fish’s behalf:

  • The Service expanded the amount of habitat protected by the goby by 20%.
  • New critical habitat protections are extended to 10 currently unoccupied lagoons and creeks, in Los Angeles County, San Louis Obispo County, Monterey County, San Mateo County, Santa Cruz County and Marin County.
  • The Service noted that part of the threat to unoccupied habitat comes in the form of rising sea levels brought on by climate change.

According to legal experts at NRDC, these are significant changes because this is one of the first times that unoccupied habitat has been extended protections due to climate issues. The new proposed habitat designation will be open to public comment through December 19.

Tidewater Goby Tidbits:

While these fish are somewhat drab in appearance, their unusual behavior is quite striking:

  • The 2-3 inch gobies live for about a year and are not closely related to other fish (they are the only species of their genus).
  • They live their whole lives in shallow, brackish water (where salt and fresh water mix) of marshes, estuaries, and lagoons on California’s coast. These are extremely fragile places and some of the state’s most endangered ecosystems due to agricultural and sewage effluents, changes in water flow, and unnatural breaching of the sand dunes that create lagoons.
  • The fish cannot live long if flushed out to sea by the tides. Perhaps because of this, they have fused front fins that seem to act like a suction cup to help them stay on the seafloor.
  • Tidewater gobies have uniquely reversed sex roles unlike most any other fish species; females are more colorful and aggressively battle for the right to mate.
  • In April or May, males dig out breeding chambers with their fins and mouths -- excreting mucous to strengthen the tunnels.
  • Females enter the chambers, breed and depart after dumping their eggs, which the males nurture and guard until the young emerge 9-10 days later.

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