Saving the Delta Smelt
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In December 2007 , a federal judge ruled that water management in the Delta must be adjusted in order to prevent the extinction of the threatened Delta smelt. U.S. District Judge Oliver Wanger ordered water agencies to maintain flow in the Sacramento-San Joaquin Delta by reducing pumping or increasing water releases upstream to prevent smelt from getting sucked into massive pumps that deliver water to farms and cities south of the Delta. Thisruling in our suit to protect the smelt is an important step forward in the fight to achieve a healthy and sustainable system in the Delta. The lawsuit was filed by Earthjustice on behalf of NRDC, Friends of the River, California Trout, The Bay Institute, and Baykeeper.
Shutting Down the Pumps to Save The Smelt
In a June court decision, Judge Wanger threw out the U.S. Fish and Wildlife’s claim that the massive water pumps in the Delta aren’t dangerous to fish. He ordered the agency to write a new assessment based on the scientific facts of the case. Baykeeper, Natural Resources Defense Council, Friends of the River, and the Bay Institute, with Earthjustice serving as legal counsel, had sued the U.S. Fish and Wildlife Service for ignoring the huge number of smelt that are killed by the water pumps. In the meantime, the judge ordered the pumps shut down to prevent the total annihilation of the Delta smelt species. The pumps were stopped for nine days before state and federal water managers resumed water delivery to farms and cities south of the Delta.
The Delta Smelt Defined - (Hypomesus transpacificus)
Delta smelt are a species of fish found only in the brackish waters of the Sacramento-San Joaquin Delta. They grow to only two to three inches in length. During the late winter to early summer, smelt travel to freshwater to spawn. When the larvae hatch, they are washed downstream to the mixing zone of fresh and salt waters. Smelt don’t live very long – most die after spawning, with only a few surviving to the next year.
Why Delta Smelt Are Important
The smelt are important for two reasons. First, they are a designated threatened species, meaning they face possible extinction. Smelt were once one of the most abundant fish in the Delta, but the population declined sharply in the 1980s when their habitat was polluted by agricultural pesticides, invaded by non-native species, and wrecked by massive water pumps delivering water to farms and cities south of the Delta. In the last several years, the population has shrunk drastically, with an estimated 90% reduction from 2006 to 2007. The population remains at critically low levels.
Second, the Delta smelt are an indicator species – the health of the smelt population is directly tied to a clean and healthy aquatic environment, so their health reflects the health of the overall Delta. In short, when the smelt aren’t doing well, it’s a sign that the Delta isn’t doing well.
Why The Smelt Are in Eminent Danger Now
2007 has been particularly perilous for the smelt. In other years, when Delta waters warm in the summer, the smelt travel downstream to colder waters near San Francisco Bay. But low temperatures and water releases from upstream reservoirs kept Delta waters cool, and the smelt population didn’t move away from the hazardous pumps. At the same time, southern California is experiencing warm, dry weather and demanding more water from Delta exports. It’s been a lethal combination for the Delta smelt, whose numbers have fallen far below healthy population levels.