PROTECTION STATUS: Threatened
YEAR PLACED ON LIST: 1993
CRITICAL HABITAT: Unknown acreage in the Sacramento-San Joaquin River Delta designated in 1994, including the entire Delta, Suisun Bay, and five sloughs
RECOVERY PLAN: 1996
RANGE: Upper reaches of the San Francisco Bay and Sacramento-San Joaquin Delta Estuary
THREATS: Increasing water diversions from the Delta, loss of habitat, competition and predation from introduced species, and impaired water quality due to pesticides and other pollutants
POPULATION TREND: The delta smelt population declined by more than 80 percent in the early 1980s, fluctuated during the 1990s, and then increased following the cessation of drought in 1992. Delta smelt again declined drastically in 2002, and the smelt population in 2005 was the lowest ever measured, just 2.4 percent of what it was when the species was listed in 1993. Numbers of juvenile smelt found in 2007 surveys were the lowest ever recorded by an order of magnitude.