Swim to the sea? These salmon take a California cruise
The record drought in California is threatening millions of salmon because newly shallow rivers lack strong enough flow to guide the fish to sea. So the government is transporting the salmon by truck and barge so that some of them, when grown, might find their way back upstream to spawn.
The New York Times
RIO VISTA, Calif. — As the Merva W puttered down the Sacramento River, it looked like any other dowdy fishing vessel headed toward the Golden Gate Bridge. But no other boat had as surprising a cargo or as unusual a mission: The Merva W was giving 100,000 young salmon a lift to the Pacific in the hope of keeping them alive.
The record drought in California is not only forcing cities to ration water and farmers to sell off cattle. It is also threatening millions of salmon because the newly shallow rivers lack a strong enough flow to guide the fish to sea. And in the warming rivers, more predators are lurking.
In an act that is equal parts despair and hope, the government is transporting the salmon by truck and barge, trying to imitate nature so that in three years some fully grown fish will find their way back upstream.
For some salmon, “this is a way of sustaining the fishery,” said Peter Moyle, a senior biologist at the University of California, Davis. “For an endangered species, it’s a desperation measure.”
This spring, some 30 million salmon will go to sea. In three years, the hope is that tens of thousands will return.
The six-hour, 40-mile boat trip — along with the ride from a hatchery in a tanker truck that transports the small salmon to the boat — takes the place of at least five days of swimming 150 miles, a telescoping of their natural lives.
The river’s water is pumped over them during the ride so they can “imprint” on their native water and increase the chances of finding their way back when the time comes.
The 100,000 salmon on the Merva W — shot onto it through a 10-inch-wide, 60-foot-long pipe attached to a tanker truck — each have identifying chips implanted; the fish trucked straight to sea have different chips. In three years, experts hope to know which fish did a better job of finding their way home.
For fishermen like Mike McHenry, captain of the Merva W, this experiment is a lifeline to a billion-dollar industry facing possible extinction. He calls the little fish in his hold “hundred-dollar bills,” because if they return as 12-pounders in three years, each pound could go for $9 or more.
California salmon had long navigated the once-marshy lowlands where the Sacramento and San Joaquin rivers meet, an area whose geography and mood feel transplanted from Louisiana’s bayous.
After the Gold Rush, this delta was completely re-engineered, bit by bit. It is now a staging area through which Sacramento River water is pumped south to farms and cities that feed and house millions.
For farmers, this water is economic lifeblood. The agricultural industry in the state made nearly $45 billion in 2012, and it has more claim on politicians’ attention than the fishing industry, as evidenced by the exceptions to pumping restrictions approved by state and federal water officials in recent weeks, according to the San Francisco Chronicle.
For two decades, such water deliveries to farms have been cut back somewhat to preserve various runs of salmon and the tiny delta smelt. With the drought, the Bureau of Reclamation ended even more deliveries. The Sacramento’s waters are heavily overallocated with pledges made to farms and cities even before the federal and state governments took the fish into consideration.
At the same time, the diverse runs of salmon and steelhead have thinned, in most cases to a shadow of their 19th-century levels.
A 2012 report in the journal “Environmental Biology of Fishes,” by Jacob Katz and Moyle, said that 81 percent of native California salmon were “threatened with extinction.” It added that bringing them all back from the brink might not be possible.
So when it comes to some of the fish — Sacramento’s fall-run chinook salmon, for example — McHenry is giving his boat and crew over to the ride-along experiment with a measure of hope.
“If we get a good return,” he said, “that means barging will work.”
McHenry, 70, started the experiment even before the drought became extreme this year. Now his work with the Golden Gate Salmon Association and the California Department of Fish and Wildlife is all the more urgent. The fierce drought may simply be an anomaly, of course, but it may be a sign of things to come.
For the past 150 years, the marshy area where salmon bred and fed has been dried, diked and dammed. During that time, nature was relatively kind to the fish.
“The last century has been exceptionally benign in terms of rain and climate and everything else,” Moyle said. “We’re probably moving back into more tumultuous weather patterns” he said, although that will “be exaggerated by climate change.”
California salmon, which live at the southern end of the Pacific’s large expanse of salmon territory, will need a lot of help to survive future droughts.
But a successful fish ride-along program will not eliminate the legal warfare pitting water agencies, fishermen and environmental groups against state and federal agencies. Water diverted to farmers is unlikely to return.
Agricultural advocates who depend on those water transfers for their livelihoods are delighted that California fishery officials have blessed the use of McHenry’s boat to help the young fish get to sea. It keeps water flowing their way.
Federal officials have also begun helping young fish to sea, although their program relies entirely on tanker trucks, which keep the fish from marking the river’s changes, making it far more likely that they will stray from their home streams on their return.
Fish advocates say that barring a significant shift in water distribution, the salmon of California are facing long-term trouble.
As John McManus, executive director of the Golden Gate Salmon Association, put it, trucking and barging programs will help — but only a little.