By Matt Weiser -- Bee Staff Writer
Monday, October 31, 2005
The threatened Delta smelt has notched another historic population low, prompting some observers to worry the tiny fish may be near extinction.
Early results from a fall count of the smelt in September and October produced a population index of 12, down from 44 recorded during the same period last year.
There are two months left in the survey, but the early results are likely to mean that officials will order reduced water exports from the Delta to Southern California starting in December.
State and federal water export pumps near Tracy kill thousands of fish every year and are considered one factor in the smelt's decline.
"We do have a high concern for those fish," said Ryan Olah, U.S. Fish and Wildlife Service branch chief for endangered species. "We anticipate we'll probably have some (water) export reductions at some point, but it's hard to say when that will be."
The Delta is a water source for 22 million Californians - about two-thirds of the state - and 5 million acres of farmland.
The finger-length smelt lives for only one year, and depends for part of its life on a narrow range of salinity in the Delta's waterways. As a result, the smelt is considered a key indicator of the health of the entire Delta, a 700,000-acre maze of sloughs and shallows at the confluence of the Sacramento and San Joaquin rivers.
Smelt also occupy a key spot in the Delta's food chain.
Lester Snow, director of the state Department of Water Resources, said he is concerned about extinction of the smelt.
"It's likely we will be curtailing pumping more as a result of those low numbers," he said. "We're prepared to respond with different pumping patterns if that is what the judgment is."
Federal water officials familiar with the situation could not be reached for comment Friday.
The fall trawl survey is considered a key measure of smelt abundance because it tallies adult fish before they move upstream to spawn. Researchers drag a net through the water at fixed points throughout the Delta. It is not a true population count, but indicates the abundance of fish in a given volume of water.
Last year's fall survey revealed a steep population decline, and the trend has continued in every survey since. The smelt is listed as threatened under the federal Endangered Species Act, but the decline involves other pelagic fish, so called because they live in the Delta's moving water column.
So far, similar declines have not been noted in salmon or in shallow-water fish.
State and federal researchers launched a $2 million study earlier this year to understand the decline. They plan to report initial results at a public meeting on Nov. 14.
In addition to water exports, other key suspects in the decline are invasive species, which may compete with the smelt for food, and water contamination.
The early results from the fall smelt survey were released Thursday by the Bay Institute, an environmental group. Tina Swanson, the group's senior scientist, said the numbers indicate the fish is in danger of extinction. Water export reductions, she said, should begin immediately.
"That's not to suggest that is the only problem these fish have, but it is the only problem we can fix fast," she said. "We need to take some very strong and positive action to protect this fish. We can't afford to lose any of them."
This is especially important, she said, because adult smelt begin moving upstream in December to spawn. This makes them more vulnerable to the export pumps. These fish need every opportunity to produce the next generation of smelt, she said.
Water export reductions to protect fish have been ordered before. Water managers created a special "environmental water account" for this purpose. It allows pumping reductions in winter and spring to protect smelt, followed by increased deliveries in summer to make up for the lost water exports.
State and federal officials buy water for this account on the open market. Snow said the account might have to be tapped earlier this year, and he said the state is prepared to buy more water to protect smelt if necessary.
But the environmental water account itself is another suspect in the smelt's decline, because increased summer pumping may be exporting a food supply crucial to the smelt.
Last week, state water and wildlife officials jointly released an "action plan" to protect the smelt. It amounts to a declaration that the state will take certain steps to restore the smelt, including the possibility of reduced water exports.
It also promises research and action in new areas. For instance, by December the state intends to finish a study on whether two major power plants in Antioch and Pittsburg are harming fish.
The power plants jointly draw as much as 3,100 cubic feet per second of cooling water out of the Delta in an area that is vital habitat for young smelt. These intakes are not screened to exclude fish, but state officials could move to require that by early 2006.
• The tiny smelt lives for only one year, and for part of its life depends on a narrow range of salinity in the Delta. As a result, the smelt is considered a key indicator of the health of the entire Delta.
• Early results from a fall count of the smelt in September and October produced a population index of 12, down from 44 recorded during the same period last year.
• Last week, state water and wildlife officials jointly released an "action plan" to protect the smelt. It amounts to a declaration that the state will take certain steps to restore the smelt, including the possibility of reduced water exports.
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