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Delta Smelt Recovery
About the delta smelt
The delta smelt (Hypomesus transpacificus) was listed as threatened under the Endangered Species Act in 1993.
Factors thought to have contributed to the decline of the species include reductions in freshwater outflow, entrainment losses to water diversions, entrainment at power plant intakes, changes abundance and composition of food organisms, environmental contaminants, and competition and predation from exotic invasive aquatic species.
DSRAM/Smelt Working Group
DSRAM - The Delta Smelt Risk Assessment Matrix - sets criteria which, when exceeded, trigger meetings of the Smelt Working Group. The group consists of experts in delta smelt biology. Read more.
OCAP
On February 24, 2005, this office issued a biological opinion on the Long-Term Operational Criteria and Plan (OCAP) for coordination of the Central Valley Project and State Water Project. The document is in PDF format.
The Service is preparing a new biological opinion to comply with a finding by the U.S. District Court (Judge Wanger) that the "OCAP BO is unlawful and inadequate," in part because it "does not provide a reasonable degree of certainty that mitigation measures will take place." Court Finding of Fact.
On Dec. 14, 2007, Judge Wanger issued an interim order directing potential pumping limits and other actions to protect the delta smelt until the new BO is completed. Judge Wanger directed the Service to complete the new BO by Sept. 15, 2008.
Delta Smelt FWS Photo
Delta Smelt Species Account
Critical Habitat
Map (PDF)
Federal Register Notice (PDF)
Newest Delta Science Report
The 2007 Pelagic Organism Decline Report provides the most recent information on factors in the decline of Delta fishes.
5-Year Status Review
On March 3 1,2004, we completed a five year status review of the delta smelt. We recommended that it remain listed as threatened.
Status Review (PDF)
Related Issues
Last updated: May 5, 2008
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