A tiny but vital creature is struggling to survive in S.F. Bay

An inhabitant of the San Francisco Bay estuary is very close to getting federal protection after decades of advocacy from environmentalists, who say the tiny fish is vital to the ecosystem.

Called longfin smelt, the 3½- to 4½-inch silver fish was once a major source of food for marine mammals and larger native fish before its population plummeted over several decades. On Thursday, the U.S. Fish and Wildlife Service announced a proposal to list the San Francisco Bay population of the little-known fish as an endangered species.