SAN FRANCISCO - Tens of thousands of imperiled Sacramento splittail and federally protected spring-run chinook salmon have died recently at Central Valley Project water pumps in the Sacramento-San Joaquin Delta, according to government figures. The news comes amidst debate over federal legislation that would exempt pumping in the Delta from Endangered Species Act protections for salmon and other fish.

“State and federal water-project pumps are pushing already-struggling salmon and native fish populations closer to extinction while Republican lawmakers are introducing legislation to eliminate environmental protections for the devastated Bay-Delta ecosystem and block restoration efforts on the San Joaquin River,” said Jeff Miller, conservation advocate with the Center for Biological Diversity. “Excessive pumping and the highest-ever water diversions from the Delta the past decade have devastated Central Valley fish populations, including commercially valuable salmon.”

Recent salvagedata from the U.S. Bureau of Reclamation show that the Central Valley Project pumps have so far killed more than 10,000 juvenile spring-run chinook salmon this year. Central Valley spring-run chinook were listed as threatened under both the state and federal Endangered Species Acts in 1999. Only three of 17 original wild spring-run chinook populations remain in the Central Valley, and numbers of spawning adult salmon are down to as low as 500 wild fish in some years. Overall Central Valley salmon numbers have dropped so low that California’s salmon fishery was closed completely in 2008 and 2009 for the first time in history.

The salvage dataalso show that the pumps have killed more than 85,000 Sacramento splittail in the past week alone. The splittail wasformerly protected as a federally threatened speciesbut was improperly stripped of Endangered Species Act protections in 2003. The depleted splittail population has declined dramatically in the past decade and has now collapsed to barely detectable numbers in state fish surveys.

Background

Spring-run chinook were once the most abundant salmon run in the Central Valley, ranging throughout the Sacramento and San Joaquin watersheds,but now only remnant wild runs remain in the Deer, Mill and Butte creek tributaries of the Sacramento River. Spring-run chinook have been decimated by construction of large dams, and populations in the mainstem Sacramento River and Feather River have hybridized with hatchery-influenced fall-run salmon. Spring-run salmon enter fresh water in the spring, while immature, and hold through the summer in deep cold pools at higher elevations, spawning in early fall.

Conservation groups first petitioned for federal Endangered Species Act protection for Sacramento splittail in 1992; the species was listed as threatened in 1999. After litigation by water agencies challenging the listing, the Bush administration improperly removed the splittail from the threatened list, despite strong consensus by agency scientists and fisheries experts that it should retain protected status. The Center for Biological Diversity sued, and the Fish and Wildlife Service agreed to revisit the tainted Bush-era decision. A recent analysisof splittail population trends by the Bay Institute shows that there has been a significant decline in the abundance of splittail during the past several decades. Splittail have fallen to consistently low levels since 2002, and the estimated abundance from 2007 to 2009 has been the lowest recorded since surveys began in 1967. However, the critically endangered splittail was again denied Endangered Species Protection by the Obama administration in October 2010.

Debate has raged over the proposal to construct a peripheral canal or tunnel to divert water from the Delta to agribusiness and Southern California and the potential impacts on endangered and declining salmon and other native fish populations.The National Research Council earlier this month slammed the state’s peripheral canal proposal for lacking credible scientific analysis of the potential impacts on Delta fish and other species. This week Gov. Jerry Brown’s administration backed off former Gov. Arnold Schwarzenegger's Delta tunnel proposal, stating that building a proposed pair of huge tunnels to facilitate water exports is no longer the top option. Any conveyance scheme that diverts more water from the Delta would likely lead to the extinction of Central Valley steelhead, chinook salmon, Delta smelt, longfin smelt, Sacramento splittail, green sturgeon and other imperiled fish species.