Thursday, May 8, 2008

"It's happened in the past"


Sea lions near Bonneville Dam weren't shot

Fisher officials are investigating if the animals died of foul play

Thursday, May 08, 2008MICHAEL MILSTEIN The Oregonian Staff
Backing away from earlier suggestions that six sea lions were brazenly gunned down at Bonneville Dam over the weekend, federal fisheries officials said Wednesday that they do not know how the animals died.

They said they initially thought, based on puncture wounds on the neck of one animal and traces of blood, that the sea lions were illegally shot while trapped inside floating cages set up by state officials.

"That seemed at first blush to be the most likely explanation," said Brian Gorman, a spokesman for the National Marine Fisheries Service, the federal agency responsible for marine mammals. "That was the assumption."

Initial reports Sunday that the animals were shot provoked outrage, atop already rising controversy over the sea lions preying on protected salmon. State officials halted all sea lion capture efforts until next year.

Examinations of the carcasses found no gunshot wounds and determined that the neck wounds were probably caused by bites from another sea lion.

Officials said they do not know that foul play was involved. The gates on the floating cage platforms are typically left open, but state officials acknowledged Wednesday that in a few past instances the gates have accidentally closed on their own.

"We have no hypothesis right now about how these animals died or how the gates came down" to trap them in the two separate cages where they were found dead, Gorman said on Wednesday. "I think anything is conceivable at this point. It might have been a malfunction."

The cages were last seen open about 7 p.m. Saturday. The sea lions were discovered dead about 11:30 a.m. Sunday.

Oregon and Washington wildlife officials placed the cages below the dam on the Columbia River as part of a federally authorized program to remove sea lions preying on protected salmon. Sea lions have gotten used to entering the open doors of the cages and resting on the floating platforms.

State crews could pull on ropes to shut the doors of the cages, corralling the animals inside so they could be removed. The ropes were tied to a railing on Cascades Island, part of the dam complex that is closed to the public.
Gorman said it's not clear why the gates closed or why the animals died. Necropsies completed at the dam complex did not identify any obvious cause of death, he said.

The heads of the sea lions were removed and sent with tissue samples to a federal laboratory in Ashland for further tests. The results of tests that could show evidence of disease or poisoning may not be available for another week or two.

Sea lion traps at Bonneville Dam and near Astoria have shut on their own a few times, said Rick Hargrave, a spokesman for the Oregon Department of Fish and Wildlife. He said those instances sometimes happened in severe weather.

"It's happened in the past," he said. "It's not a reoccurring issue."

In the past instance he was aware of at Bonneville Dam, no sea lions were in the trap when it closed. Officials at the dam noticed it was shut and reopened it.

He said it takes "quite a tug" to shut the door.

The dam is studded with surveillance cameras, but officials have refused to say whether they may have observed activities around the sea lion traps.

The dead animals included two California sea lions and one Steller sea lion in each of two traps, Gorman said. Both species are federally protected, with Steller sea lions falling under the extra protection of the Endangered Species Act.

California and Steller sea lions are "not fully compatible" when held together, Gorman said. He said the puncture wounds on the neck of one of the animals appeared to be inflicted by another sea lion in the trap.

X-rays found metal fragments in tissue around the neck of two of the dead sea lions, and a metal slug was found in the blubber of one of the animals. However, neither the fragments nor the slug appeared to have caused their death and may have been associated with old wounds. Mark Oswell, a wildlife enforcement officer for the federal fisheries service in Silver Spring, Md., said Wednesday that human involvement still cannot be ruled out and said dehydration, heat exhaustion or panic could have been factors.

But Sharon Young of the Humane Society of the United States, which has fought state plans to kill sea lions, said humans must have played a role in the deaths.

"The animals would not have just in a few hours died of natural causes," she said.

Meanwhile, a report released Wednesday did identify the likely cause of death for a sea lion trapped by state officials at Bonneville Dam in late April and transferred to Point Defiance Zoo and Aquarium in Tacoma.

They said the 1,452-pound sea lion, the largest ever captured anywhere, died while sedated for a health screening because it was extraordinarily fat. Its extreme weight pressed down on its internal organs while under anesthesia, said Steven Jeffries of the Washington Department of Fish and Wildlife.

"It was so obese -- so fat -- that its head went back into the fat rolls of its body," Jeffries said.

Nearly 5 inches of fatty blubber covered the animal's sternum. Its incredible weight can be attributed to the high fat content of the salmon it was eating at Bonneville Dam, Jeffries said.

Sea lions attempt to put on as many pounds as possible before heading to their breeding grounds in the summer, where males spend little time eating because they devote full attention to maintaining their territories, he said.

The Associated Press contributed to this story. Michael Milstein: 503-294-7689;