PROTECTION STATUS: Not listed
RANGE: Estuaries along the Pacific Coast, from San Francisco Bay to Alaska
THREATS: Degraded environmental conditions in the Bay-Delta Estuary caused by massive water diversions that reduce freshwater inflow; loss of fish at agricultural, urban, and industrial water diversions; direct and indirect impacts of nonnative species on food supply and habitat; and lethal and sub-lethal effects of pesticides and toxic chemicals
POPULATION TREND: Longfin smelt may already be extinct in some smaller estuaries in northern California, and the San Francisco Bay-Delta population has experienced two catastrophic population plunges in two decades. So far, throughout the 2000s, the Bay-Delta longfin smelt population has been at just 3 percent of levels measured fewer than 20 years ago, and numbers in this estuary dropped to record lows from 2004 to 2007.