As the tally of sea lion deaths at the Bonneville Dam in Washington state grows to four, happier news comes from Chicago, where the Shedd Aquarium has pledged to take the next sea lion caught eating salmon.
"It's what we all would prefer see happen," said Craig Bartlett, a Washington state wildlife official. "We'd rather see them find new homes."
Over the past several weeks, Oregon and Washington state officials have captured and euthanized California sea lions seen eating salmon at the Columbia River dam.
The two states, along with Idaho, have been granted exemption from the federal Marine Mammal Protection Act, allowing officials to kill the sea lions. The officials argue that the animals are having a “significant negative impact” on wild, endangered salmon populations.
Bartlett said the Shedd is seeking to replace a sea lion that died after developing genital cancer.
The Shedd Aquarium did not respond to requests for comment.
Bartlett said precancerous genital herpes has been found in many of the sea lions trapped at the dam. He added that the Shedd has certain conditions that must be met for the aquarium to accept a sea lion, including the animal's general health and size.
Bartlett said the salmon have been slow to move up the river this year, though state wildlife officials are expecting record-high runs.
A spokeswoman for the Humane Society of the United States said that since the federal government cleared the way for states to kill the sea lions in 2008, 10 have been taken off the “hit list” and transferred to aquariums or zoos.
In 2008, three went to SeaWorld San Antonio and three to SeaWorld Orlando. In 2009, two went to the Shedd (including the one that is now being replaced) and two to the Gladys Porter Zoo in Brownsville, Texas.
Sharon Young, the Humane Society's marine issues field director, said about 35 have been killed.
According to the U.S. Army Corps of Engineers, the largest number of sea lions seen any one day this year at the dam was 10, the lowest count since 2002. Combined, the sea lions have eaten 116 salmon – 75 Chinook and 41 steelhead – and 14 unknown fish species from Jan. 1 to April 18.
“Again, the lowest of any year since they have been observing,” Young said.
According to the Army Corps, which tracks the salmon at the dam, 6,322 salmon have been counted since the beginning of the month, which means the sea lions have eaten about 2 percent of the run.
The Humane Society filed a lawsuit last month against the National Oceanic and Atmospheric Administration, which authorized the states to kill the protected mammals. The society argued that the killings violate the Marine Mammal Protection Act and that the government has failed to show that sea lions, which are natural salmon predators, kill a significantly large number of salmon.