On February 2, 2011, the United States District Court for the Northern District of California approved a settlement agreement (pdf) between the U.S. Fish & Wildlife Service ("Service"), the Center for Biological Diversity, and The Bay Institute, obligating the Service to reconsider the status of the longfin smelt (Spirinchus thaleichthys), including the San Francisco Bay-Delta population.  Under the terms of the settlement, the Service must conduct a rangewide review of the species and issue a new listing determination by September 30, 2011.

The species has a range from Monterey Bay, California to Prince William Sound, Alaska, and there are two known, landlocked populations.  Across much of that range, longfin smelt are abundant.  But abundance data indicate that the San Francisco Bay-Delta population has declined substantially.

In 2009, the Service issued a 12-month finding (pdf) concluding that the Delta population of the longfin smelt did not meet the definition of a distinct population segment, and therefore did not qualify for listing under the federal Endangered Species Act.  Shortly thereafter, the Center for Biological Diversity and The Bay Institute filed a lawsuit challenging the Service’s decision.  Today’s settlement provides the Service with an opportunity to review the petition and make a determination in light of the best scientific and commercial data currently available.

In March 2009, the California Fish and Game Commission voted to list the longfin smelt as a threatened species (pdf) under the California Endangered Species Act.  The California Department of Fish and Game prepared a status review of the species recommeding state listing in January 2009, which is available here.