The U.S. Fish & Wildlife Service (Service) has determined that protection under the Endangered Species Act (ESA) for the San Francisco Bay-Delta (Bay-Delta) population of longfin smelt is “warranted but precluded.” The Service also determined that listing the longfin smelt rangewide is not warranted at this time.

The Service’s decision is in response to a lawsuit brought by environmental groups challenging the Service’s 2009 determination (pdf) that the Bay-Delta population of longfin smelt is not distinct from other populations in the species’ geographic range. In a settlement agreement entered into in February 2011, the Service agreed to conduct a status review of the species, evaluating whether the entire range of longfin smelt should be listed as endangered or threatened, and reconsidering whether the Bay-Delta population of longfin smelt constitutes a distinct population segment (DPS) under the ESA.

In its decision published today in the Federal Register, the Service found (pdf) that the Bay-Delta longfin smelt meets the requirements of the Service’s DPS policy, and therefore can be listed under the ESA. The Service also determined, based on the best available scientific and commercial information, that listing the Bay-Delta DPS of longfin smelt is warranted but precluded by higher priority actions. The Service will add the Bay-Delta longfin smelt to its candidate species list, and will develop a proposed rule to list the smelt as its priorities allow. The Service will make a determination regarding critical habitat during the development of the proposed listing rule.