Local environmental advocates said federal endangered protections for longfin smelt, a species of small fish whose abundant population in San Francisco Bay has been declining since the 1980s, is “decades overdue, but it’s not too late” to reestablish the regional population.

The U.S. Fish and Wildlife Service on Monday listed longfin smelt found in the San Francisco Bay Delta as endangered under the Endangered Species Act, marking the culmination of yearslong advocacy and legal efforts by multiple organizations.