Sea Lions Turn Salmon Run into Buffet
by Joel Millman
Wall Street Journal, May 20, 2011
Feeding Frenzy at Columbia River's Bonneville Dam Becomes Federal Case Weighing the Fate of Two Protected Species
CASCADE LOCKS, Ore. -- It's mammal vs. fish in the churning waters of the Columbia River, where California sea lions are pitted against Chinook salmon in a struggle for survival that federal agencies -- and now a federal court -- must sort out.
The sea lions are feasting on this area's choicest runs of salmon, steelhead trout and sturgeon, and during the last decade have been taking thousands of fish every spring. The burning issue: should anything be done to keep the enormous beasts from turning Bonneville Dam into a buffet? And, if so, should lethal removal be one of the options?
Trapping and branding -- and for persistent predators, euthanasia -- of sea lions has been legal along the Columbia River for much of the past decade. A sea lion has to be a documented repeat offender to get on a "kill list," which then only occurs if it swims into a special trap where state wildlife workers can administer a lethal injection.
Sea lions used to be rare this far inland, scientists say. Generally they prey on fish either in the open waters of the Pacific Ocean, or at the mouth of the Columbia. The number of fish taken upriver here has been rising -- to nearly 8,000 last year, or almost eight times the 2002 total -- out of a annual total migration of about 300,000 Chinook salmon, the main species during the months sea lions arrive.
"They've really become a problem," says Myranda Blodgett, a registered member of the Yakama Nation, one of four native tribes permitted to harvest and market salmon along the river. "And they're so smart. They know where our pools are. They take fish right off our lines."
Scientists say declining numbers of ocean smelt may have forced the sea lions upriver in search of protein. Gangs of breeding-age males arrive here every spring to get fat before the long migration back to southern California, where they'll compete to be the "alpha" males of each pod and mate with dozens of females.
Since 2008, 27 sea lions have been euthanized, and 10 were moved to zoos.
Oregon officials most recently killed a sea lion on the river in September, just prior to a federal court order staying the practice. During the hiatus, biologists working for the U.S. Army Corps of Engineers continued to tally the number of sea lions coming to the dam, the type of sea lion -- California or Steller -- and data on which ones stop to feed, and how many each individually consumes.
This month, state wildlife officials in Oregon and Washington received permission to again trap and kill California sea lions deemed "problem" predators under guidelines elaborated by the Marine Fisheries Service of the National Oceanic and Atmospheric Administration. But Friday, the Humane Society of the U.S. went to court seeking to block lethal removal of sea lions in the Columbia River.
The Humane Society, along with the Wild Fish Conservancy, a co-litigant in Friday's filing, says sea lions have consumed an average of 2.5% of Columbia River salmon in recent years, while at the same time commercial and sport fishermen have taken up to 17% of recent salmon runs.
"Federal law allows the killing of sea lions only in very limited circumstances, when they are having a significant negative impact," said Jonathan Lovvorn, the Humane Society's chief counsel for animal-protection litigation. "The National Marine Fisheries Service's decision to kill hundreds of native marine mammals to reduce salmon losses," while simultaneously authorizing large catches by people "is both outrageous and patently illegal."
"That one looks like C04," says one of the biologists documenting sea lions here, Bjorn Van der Leeuw, as he points to a furry brown mass frolicking in the water. He's referring to the letters on the half-ton California sea lion, dating back to when the beast first swam into a trap and received the branded code on its back. The animal also is identifiable by a circular white scar on its dorsal posterior, says Robert Stansell, another scientist here.
Nicknamed "Obessius" by his staff, Mr. Stansell says C04 is on his second visit to Bonneville. A check of C04's rap sheet reveals he was spotted here last year for seven days, when he took 10 salmon. This season he's been on site for 20 days, and eaten 33 fish, which on average weigh between 15 and 30 pounds.
Compared to C287, C04 is a piker. Branded at the mouth of the Columbia in Astoria nine years ago, C287 is the reigning champ. He didn't swim the 145 miles from the Pacific up to Bonneville until 2005, when he stayed a week and ate just two salmon. Since then he's upped his intake considerably: 50 salmon in 2007, 75 in 2008, 157 in 2009 and 198 in 2010 -- including 12 in one day last April.
"He's a fish-eating machine," laughs Mr. Van der Leeuw, who marvels at how C287 has staked out a spot beneath one of Bonneville Dam's two powerhouses, yet has avoided capture all these years. In 32 days at the dam this season, C287 was seen to take 115 salmon, and that's just the meals his team has documented during daylight hours on weekdays, Mr. Van der Leeuw says.
The legal stalemate is matched by an ethical one: which species is under a greater threat, sea lion or salmon? Recently, both the fish and the marine mammals seemed on the verge of extinction. Today both seem on their way to recovery.
In the case of California sea lions, considered endangered when Congress passed the 1972 Marine Mammal Protection Act, the species' numbers have increased substantially -- to an estimated 265,000 along the West Coast.
NOAA now authorizes lethal removal only of California sea lions, although lately the larger, less numerous Steller species appears to be eating much more Columbia River fish.
With salmon stocks recovering, many environmentalists say even incorrigibles like C287 should be spared.
Myranda Blodgett, the Yakama fish-hunter, disagrees. "They call them natural predators, but they're not," she says. "We're the original natural predators here."
Killing Sea Lions Will Not Save Columbia River Salmon by John Balzar, Seattle Times, 2/7/8
Sea Lions vs. Salmon: Restore Balance and Common Sense by Fidelia Andy, Seattle Times, 2/15/8
Survival of Snake River Salmon & Steelhead Data compiled July 2004 by www.bluefish.org
learn more on topics covered in the film
see the video
read the script
learn the songs