March 5, 1993 – The delta smelt was listed as a threatened species under the federal Endangered Species Act.
December 9, 1993 – The delta smelt was listed as a threatened species under the California Endangered Species Act.
March 8, 2006 – Based on recent population viability and extinction risk analyses showing that the delta smelt was in imminent danger of extinction, the Center petitioned the U.S. Fish and Wildlife Service to change its federal listing status from threatened to endangered on an emergency basis.
February 7, 2007 – The Center petitioned the California Fish and Game Commission to change the state listing status from threatened to endangered on an emergency basis.
April 12, 2007 – The California Fish and Game Commission denied a Center request for emergency action to change the smelt's state listing status from threatened to endangered. However, the Commission agreed that endangered status may be warranted and initiated a species status review. Surveys from the year revealed a juvenile smelt population crash of 92 percent from the previous low, recorded in 2006.
May 24, 2007 – The Center filed a notice of intent to sue the Service for failing to respond to our federal petition to uplist the delta smelt from threatened to endangered.
July 10, 2008 – Twenty-five months late, the Service made a positive initial finding on the Center's petition to uplist the delta smelt from threatened to endangered status.
March 4, 2009 – Thanks to our 2007 petition, the California Fish and Game Commission voted to upgrade the delta smelt's protection status from threatened to endangered.
March 24, 2009 – The Center joined with the Bay Institute to file a notice of intent to sue the U.S. Fish and Wildlife Service for failing to make final determinations on federal Endangered Species Act protections for the delta smelt and longfin smelt.
September 2, 2009 – The Center and a coalition of conservation and commercial fishing organizations sent a letter to the California legislature opposing a flawed Delta bill package and opposing the approval of an environmentally destructive “peripheral canal.” The dams that would result from the bill package, along with the canal, had the potential to devastate the Bay-Delta ecosystem and its native fisheries.
November 13, 2009 – The Center sued the Fish and Wildlife Service to compel it to upgrade the delta smelt's Endangered Species Act status from threatened to endangered.
March 19, 2010 – The National Academy of Sciences released a peer-review report that validated federal “biological opinions” and federal actions, particularly seasonal reductions in water pumping, to protect endangered fish species in the San Francisco Bay-Delta.
February 12, 2015 – The Center filed a lawsuit in federal court in California against the Fish and Wildlife Service for failing to ensure three widely used pesticides — atrazine, 2,4-D and alachlor — wouldn't jeopardize the survival of the delta smelt and Alameda whipsnake.