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For Immediate Release, April 12, 2007

Contact: Tina Swanson, The Bay Institute, (415) 272-4501
Jeff Miller, Center for Biological Diversity, (510) 499-9185
Kate Poole, Natural Resources Defense Council, (415) 875-6100

Fish and Game Commission Will Decide on State Endangered Status
For Disappearing Delta Smelt

Stronger Protections Needed as Delta Fish Populations Collapse and Delta Ecosystem Unravels

SAN FRANCISCO– The California Fish and Game Commission today will consider an emergency request to change the status of the delta smelt (Hypomesus transpacificus) from threatened to endangered under the California Endangered Species Act. Conservation groups submitted a petition in February to uplist the species to endangered due to catastrophic declines of the smelt population. The groups argue that the change is necessary to reflect new science that shows the species is at imminent risk of extinction and to compel fisheries agencies to implement recommended actions needed to protect the smelt and its Delta habitat. In March 2006 the organizations also petitioned to change the fish’s federal listing from threatened to endangered.

The delta smelt is a small, nearly translucent fish found only in the upper San Francisco Bay and Sacramento-San Joaquin Delta. It was once one of the most common and abundant of the Delta’s open water fishes, but in the 1980s its population plummeted by more than 80 percent. The species was listed as threatened under both the state and federal endangered species acts in 1993. In recent years the species’ population has completely collapsed, and abundance levels the past three consecutive years have been the lowest on record. In 2005, smelt abundance was the lowest ever measured at just 2.4 percent of its 1993 population; the 2006 and 2004 abundance levels were the second and third lowest respectively.

“The science couldn’t be clearer: delta smelt, one of the best indicators of environmental conditions in California’s most important estuary, are in critical condition due to reduced freshwater inflows, record-high water diversions, and harmful non-native species that thrive in the degraded Delta habitat,” said Dr. Tina Swanson, senior scientist with the Bay Institute.

“Delta smelt are on a rapid extinction trajectory and need more state and federal protection,” said Jeff Miller of the Center for Biological Diversity. “Regulatory agencies cannot continue to approve record levels of water diversion at a time when the entire Delta ecosystem is in crisis. The state needs to commit to implement the management changes recommended by scientists in the Pelagic Fish Action Plan.”

“Delta smelt are an estuarine version of the canary in the coal mine, and the plummeting numbers show that the Delta is on the verge of collapse,” said Kate Poole with the Natural Resources Defense Council . “Urgent action is needed to protect habitat and water quality, both for the smelt and the 20 million Californians who rely on the Delta for clean drinking water.”

Delta smelt spend their entire lives in the Delta, the west coast’s largest estuary, in shallow open waters at the interface of inflowing fresh water from the Sacramento and San Joaquin Rivers and salt water from the ocean. Threats to the species include massive and increasing diversions of fresh water from the Delta and its tributary rivers, loss of habitat, impaired water quality from pesticides and other pollutants, and competition and predation from introduced species.

The Delta is a major hub for California’s water system. The State Water Project, federal Central Valley Project and thousands of private water diversions take as much as 65 percent of the Delta’s total freshwater inflow, killing both spawning adult delta smelt and their young in pumps and diversions. At times, pumping levels are so high they reverse flow in the San Joaquin River, confusing and delaying adult fish migrating upstream, impairing downstream transport of larval and juvenile delta smelt from the upper estuary to their brackish water rearing habitat, and drawing water and fish into the pumps. Hydraulic models indicate that when water export rates are high, virtually all young smelt in the southern Delta are sucked into the pumps. The recent population decline coincides with significant increases in water exports by the state and federal water projects (seasonal exports in the 2000s are up to 49 percent higher than in the early 1990s) and higher mortality of smelt at the pumps. The five highest years of water exports from the Delta have occurred since 2000.

New scientific analyses show that recent record-high Delta water exports are related to the delta smelt population decline. However, despite this new information and crashing fish populations, state and federal agencies charged with protecting the smelt and its habitat have done little to reverse the decline.

The current management of smelt habitat is “dangerously unsustainable” according to a report released in February by the Public Policy Institute of California, Envisioning Futures for the Sacramento-San Joaquin Delta, which warned that the Delta “could become an environmental and economic disaster.” An Alameda County judge ruled last month that the Department of Water Resources has been illegally pumping water out of the Delta because they do not have a permit under the California Endangered Species Act and are killing listed species, including delta smelt and winter-run and spring-run salmon. The state has 60 days to come into compliance. Earlier this week, the Department of Water Resources announced its proposal to “comply” with the ruling by relying on a federal permit which has also been challenged in court and is currently being reevaluated by federal regulators concerned about the delta smelt’s low numbers.

The delta smelt is not the only fish species facing extinction in the Delta. Since 2002, scientists have also documented catastrophic declines of longfin smelt, threadfin shad and striped bass. Numbers of white and green sturgeon in San Francisco Bay and the Sacramento River have fallen to alarmingly low levels as well. The green sturgeon was federally listed as threatened in 2006.

More information regarding delta smelt is available on the Center for Biological Diversity Web site at


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