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For Immediate Release, March 19, 2010

Contact: Jeff Miller, (510) 499-9185

Report Finds Delta Water Pumping Restrictions to Protect Fish "Scientifically Justified"

SAN FRANCISCO, Calif.— The National Academy of Sciences today released a peer-review report that validates recent federal “biological opinions” and federal actions, particularly seasonal reductions in water pumping, to protect endangered fish species in the San Francisco Bay-Delta.

“The Academy of Sciences report confirms that the best available scientific information demonstrates that unsustainable water diversions are a major factor driving salmon and other native fish in the Delta to extinction, and that restrictions on excessive pumping mandated by the Endangered Species Act are justified and necessary,” said Jeff Miller, conservation advocate with the Center for Biological Diversity. “It is past time to restore sufficient flows to ensure the health of the Bay-Delta ecosystem.”

In 2008 and 2009, the U.S. Fish and Wildlife Service and National Marine Fisheries Service issued biological opinions under the Endangered Species Act that required reduced water diversions from the Delta to prevent the extinction of delta smelt, Central Valley chinook salmon and steelhead, and green sturgeon. To keep the record amounts of subsidized water flowing, agricultural interests filed litigation, lobbied Congress, spread disinformation about the economic impacts of the restrictions, and attempted to downplay the effects of massive water diversions.  Despite the biological opinions undergoing five peer reviews to ensure that they were based on the best available science, Senator Dianne Feinstein, D-Calif., pushed for additional review, and Congress and the Interior Department asked the National Academy of Sciences to provide a further scientific evaluation of the actions in the biological opinions.

“With the smallest return of fall-run salmon ever recorded in the Sacramento River, it is now more clear than ever that we need to restore and maintain flows to the Delta,” said Miller. “The National Academy of Sciences report confirms that freshwater flows are essential to endangered fish, the fishing jobs dependent upon healthy salmon runs, and the whole ecosystem.”

Unsustainable water exports, in combination with the effects of dams, invasive species, pesticides and water pollution, and other stressors, have caused the collapse of nearly all native open-water and migratory fish populations in the San Francisco Bay-Delta, such as runs of chinook salmon and steelhead trout, white and green sturgeon, delta smelt, longfin smelt, and Sacramento splittail. These fish declines correlate with the past decade of record water diversions at federal and state pumps in the Delta and have resulted in $270 million in economic losses and 2,700 lost fishing jobs in 2009 alone with the closure of the state salmon fishery.

“If we don’t protect the Bay-Delta’s endangered species and the ecosystem as a whole, there won’t be fishing or farming jobs,” said Miller. “The massive expansion of water pumping over the last decade was clearly unsustainable in our thirsty state.”

The National Academy of Sciences study found that the specific environmental triggers to indicate when water diversions should be reduced to protect native fish need further monitoring and review. The Academy will provide a second report to review other stressors on native fish, which agricultural interests have attempted to highlight to divert attention from record water diversions.


After rebounding from record low levels at the end of the last major drought in the early 1990s, populations of California’s salmon and other native fish crashed during the Bush administration years, when agency science was politically manipulated to allow increased water exports from the Bay-Delta. As water exports increased to record levels, numerous fish populations declined to historic lows, requiring the closure of California’s 150-year-old salmon fishery in 2008 and 2009. 

In 2007 and 2008, the twisted reasoning and shoddy science underlying endangered species permits (called “biological opinions”) prepared under the Bush administration led a federal district court judge in Fresno to invalidate the permits, ruling that additional restrictions on the state and federal water projects were necessary to protect endangered species, and to impose some interim protections for native fish in the Delta while new biological opinions were prepared. The new biological opinions were issued in late 2008 and in June 2009. The biological opinions require the agencies to set operational restrictions using an adaptive management process that considers the geographic distribution of fish, water temperatures and water quality, the number of fish that are being killed by the pumps, and other scientific data. The operational measures in the biological opinions build on the restrictions imposed by the federal court in 2007, which were explicitly found by that court to be based on the best available science.

The San Francisco Bay-Delta ecosystem, an ecologically important estuary and a major hub for California’s water system, is now rapidly unraveling. Once-abundant fish species are in critical condition due to record-high water diversions, pollutants, and harmful nonnative species that thrive in degraded Delta habitat. Since 2002, scientists have documented catastrophic declines of delta smelt, longfin smelt, threadfin shad, Sacramento splittail, and striped bass. The Sacramento River fall run of chinook salmon, once the most abundant salmon run on the West Coast, has declined from 768,000 fish in 2002 to 66,000 in 2008 to 39,500 in 2009, the lowest number ever recorded. The critically endangered winter run of chinook salmon has declined to 4,483 fish, and the spring run has declined to 4,506 fish. White and green sturgeon numbers in San Francisco Bay and the Sacramento River have also fallen to alarmingly low levels; the southern green sturgeon population was federally listed as threatened in 2006.

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