East of San Francisco Bay, a steel bucket full of 90 gallons of water is pressurized to rescue the dear cargo. The metal roars because it spins, displacing increasingly water until finally a pair of beating young Chinook salmon emerges.
These young, 2-inch-long fish have been put in peril by giant pumps that push water south to thousands and thousands of Californians and farms. Saving them from potential danger has been the first goal of the John E. Skinner Delta Fish Protective Facility since 1968.
But the plant has recently attracted public attention because of an increase in fish deaths and has drawn the ire of environmentalists and anglers. But that doesn't mean farmers are completely happy, because the pumps are delivering less water despite the second yr of drought-shattering storms.
An evaluation of Department of Fish and Wildlife data by the Sacramento Bee shows that state and federal water diversions from the Sacramento-San Joaquin River Delta have killed an estimated 600,000 Chinook salmon and 50,000 steelhead trout since 2002.
“That's a lot of fish, including many commercial and many endangered species, that have to be killed year after year,” said Jon Rosenfield, chief scientific officer for the San Francisco Baykeeper environmental group.
“No organism is designed to endure one more mortality ad nauseam on top of all the other things it's dealing with,” he said. “It's no wonder populations are declining. Some years the impact is big, some years less, but it's always there.”
In this rare yr of average rainfall, close monitoring of the pumps underscores a continuing tension in California's water system: The more water that’s pumped out of the beleaguered Delta, the harder it hits the beleaguered fish.
The Department of Water Resources reports that because of environmental regulations, relatively little has been pumped for export this yr and that overall population numbers of protected fish species remain high despite peak pumping.
This yr has been particularly deadly, state figures show. Pumping killed an estimated 3,600 winter Chinook in February and March, the very best number killed in a two-month period in 20 years.
And in February and March, about 3,200 steelhead trout died, the very best number since 2007.
The exact reason for this yr's high mortality is unclear, fish scientists said, and the Delta pumps are only one in every of many threats to fish survival in California's most vital waterways, including habitat loss and drought.
However, they agree that this problem shouldn’t be ignored.
The lucky few catch
California's large water pumps and the nearby state pumps that pump water into the Central Valley Project canals are so powerful that they often alter the natural flow of water in parts of the southern Delta.
Not only are the fish vulnerable to being killed by the pump, government scientists say, but also they are vulnerable to being inadvertently drawn into waters where predators lurk.
The pumps divert water from the delta to California's state and federal water projects, with most of it supplying the state's high-yield agriculture industry and the remaining supplying cities.
The entrance to the state-owned Harvey O. Banks Pumping Station opens onto a shallow reservoir called Clifton Court Forebay. It is teeming with non-native striped bass and other predatory fish that feed on juvenile salmon, steelhead trout and other native species.
Government studies have shown that about 75% of the young salmon that enter the forebay are killed by predators. As a part of these studies, government scientists have tried lately to catch and relocate non-native fish, but with little success.
The fish that manage to flee the predators come across an ingenious network of underwater barricades within the fish protection facility, about three kilometers from the pumps. Metal grids guide the fish into the ability and never to the pumps.
The fish go through large pipes, enter other large channels, and at last enter the constructing through smaller pipes, where they find yourself in the large concrete tanks. Government scientists say that just about 80% of the fish that reach the fish facility are caught through this method.
After being caught, the fish are trucked and released back into the delta. These fish are considered “salvage” and are utilized by government scientists to estimate the variety of fish “lost” from the system based on previous studies.
“CDFW conducted a series of studies from the 1980s to the early 1990s examining losses throughout the project,” said Javier Miranda, DWR's environmental program manager for fisheries monitoring on the state water project.
In recent years, his job has been to duplicate those studies in additional detail to find out whether the state's water systems are still causing the identical level of fish loss.
“The fact is, yes, things are still the same as they were 20 years ago,” he said.
Some environmental groups are calling for fish screens to be installed along the forebay gates to stop fish from entering, but state scientists argue that this may not necessarily solve the issues.
Trends in government data show that estimated fish loss at pumps varies widely from yr to yr.
Since 2002, it’s estimated that a mean of 53,000 Chinook salmon or steelhead have been killed when state and federal facilities pumped at the least 5 million acre-feet of water. In years when fewer than 4 million were pumped, only a mean of 8,200 died.
“We are doing everything we can to improve the fish's chances of survival and return them to the Delta safe and sound,” said Trent Schaffer, branch manager of the state water project's Delta field division. “It's a simple answer. We take our job very seriously.”
No easy solutions
California's mighty rivers once teemed with salmon. Today, dams prevent them from entering the cold mountain streams to spawn. State hatcheries raise and release thousands and thousands of salmon every year to stop population decline.
But these efforts have been in vain, and salmon and other native fish species are in grave danger. It is estimated that about 5.5 million salmon returned to California's rivers within the nineteenth century. Over the past five years, state and federal fisheries agencies have counted a mean of fewer than 200,000 fish.
Now the business salmon fishing season, which relies on fall salmon, has ended for the second yr in a row. Spring salmon is threatened, and winter salmon, together with steelhead trout, are endangered under the Endangered Species Act.
While state officials and scientists acknowledge deficiencies of their facilities, comparable to the pre-dwelling pool teeming with predators, they are saying they’re working to enhance their operations.
For example, within the northern delta, DWR has installed a barrier of bubbles, flashing lights and pulsating sounds to discourage migrating fish from entering the more dangerous southern delta, where the harmful forebay is positioned, and direct them toward San Francisco Bay.
The ministry also said it’s using genetic testing technologies to more quickly distinguish between endangered and non-endangered salmon species, which could facilitate fishing through higher management.
Governor Gavin Newsom has emphasized his commitment to salmon recovery. In January, he unveiled a salmon strategic plan that features plenty of improved measures, comparable to habitat restoration and modernizing fish farming.
The department has also sought to enhance the operation of the fishery by utilizing genetic testing technologies to more accurately distinguish between endangered and non-endangered salmon species.
Despite these efforts, State Water Project officials have limited this yr's allocation to 40 percent of suppliers' total allocation – the identical amount federal agencies have set for agricultural water districts south of the Delta.
“If anything, regulatory actions designed to protect juvenile salmon have made the problem worse,” said Cavallo, science adviser to the Coalition for a Sustainable Delta. “Pumping restrictions have reduced river flow and restricted access to one of the best survival routes for fish from the San Joaquin River basin.”
But Rosenfield, the Baykeeper scientist, pointed to the core goals of the Delta Protection Act and the necessity to prioritize conserving and reducing our dependence on water from the estuary.
“We should actually be pursuing two goals that are in a life-or-death conflict. One is to improve the supply of water or increase the reliability of the supply, and the other goal is to protect the ecosystem,” he said. “Nobody talks about the third goal, which is to reduce dependence on the delta.”
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