WASHINGTON (CN) - The U.S. Fish and Wildlife Service has finalized and revised critical habitat for a small California tidewater fish, expanding the habitat by 20 percent in response to a legal challenge by the National Resources Defense Council (NRDC), according to the federal agency's statement.
The NRDC sued the agency when the 2008 critical habitat designation excluded areas unoccupied by the fish that are essential to the species' survival, according to the group's statement.
The goby lives in brackish waters such as coastal salt water marshes and lagoons throughout the length of the California coastal region. Its population is considered to be a metapopulation, or a system of semi-isolated subpopulations with some migration between the isolated groups for gene exchange and for recolonization.
In the settlement agreement between the USFWS and the NRDC, the federal agency agreed to include unoccupied areas to assist in metapopulation maintenance, according to the final rule
The threats to the fish include loss of wetland habitat, water diversion, agricultural and sewage effluents, cattle grazing and introduced species. The species is further challenged by the effects of climate change as melting ice and thermal expansion of the sea water are projected to cause sea level rise resulting in a loss of 65 percent of the California saltmarshes by 2100, the final rule stated.
Commenting on the expanded critical habitat for the goby, the NRDC said, "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."
The federal agency's recovery plan for the fish recommends a program of introduction and reintroduction of tidewater gobies into the habitat to minimize the chance of localized die-offs resulting in the extinction of the broader metapopulation. "The species needs habitat areas that are arranged spatially in a way that will maintain connectivity and allow dispersal within and between units," the rule said.
The 2008 critical habitat designation of 10,003 acres is now expanded to 12,156 acres in fourteen counties stretching along the California coast from San Diego County in the south to Del Norte County in the north, the agency said. The new designation includes 21 additional units, of which 8 are currently unoccupied.
Approximately 24 percent of the habitat designation is on privately held land. "Areas identified as critical habitat do not become refuges or preserves, nor does critical habitat impact private landowners taking actions on their land that do not require federal funding or permits," the agency said.
The final rule is effective March 8, 2013.