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Sea Lion Cages Were Outside
Bonneville Dam Surveillance

by Michael Milstein
The Oregonian, May 9, 2008

Officials acknowledge security cameras weren't trained on the animals
to monitor activities or to prevent foul play

No security cameras were pointed at the floating cages where six sea lions were mysteriously found dead at Bonneville Dam over the weekend, federal authorities said Thursday.

State officials responsible for the trapping of sea lions at the dam also acknowledged there were no measures to monitor activities around the cages or prevent foul play when state crews were not present.

Although the dam is studded with surveillance cameras and security was tightened after the Sept. 11 attacks, none watched the cages set up by state officials, said Brian Gorman, a spokesman for the National Marine Fisheries Service.

He also said there was no sign that ropes used to close the cage gates had been tampered with. The doors were left open when the cages were not being used to trap sea lions so that the animals would get used to resting on the platforms.

But the dead sea lions were found in cages with the gates closed. Officials initially speculated that someone shut the doors and shot the animals, but later found no evidence they had been shot and said the doors may have malfunctioned.

One state official on Thursday raised the possibility that fluctuating water levels below the dam could have triggered the cage doors to close without any human interference.

Many biologists and others working on the sea lion trapping program now wonder whether the door shut inadvertently and the sea lions somehow died inside, said Charlie Corrarino of the Oregon Department of Fish and Wildlife.

"That's something that's crossed everybody's mind," he said.

State officials undertook the trapping, with federal permission, to reduce the number of sea lions preying on protected salmon.

The ropes to the cage doors were typically tied to a railing on Cascades Island, part of the dam complex off-limits to the public. State crews would pull the ropes to shut the doors. But the cages float freely, so a drop in the water level could have also put tension on the ropes, Corrarino noted.

Water records highlight that possibility. Real-time data maintained by the U.S. Geological Survey show that the water level below Bonneville Dam, where the cages were located, dropped more than 4 feet between Saturday morning and early Sunday, reaching its lowest level in more than three days.

The protected sea lions were found dead around noon Sunday.

If the ropes had been tied off when the water level was higher, the dropping water could have pulled them tight without any human help.

Oregon Fish and Wildlife Service spokesman Rick Hargrave said federal investigators are likely evaluating that possibility. The cages have closed on their own in some past instances, he said.

However, there's still no explanation for how the animals died. Corrarino said the sea lions rely on the water to maintain their proper body temperature and, trapped in their cages, might have overheated.

But Bonneville temperatures were not especially high Saturday or Sunday, according to National Weather Service data. Steven Jeffries, a marine mammal researcher with the Washington Department of Fish and Wildlife said sea lions often spend many hours out of the water.

"Their normal day would consist of laying in the hot sun for hours," he said.

Although the male sea lions are beginning to become territorial and would sometimes lie in the open doors of cages to keep others out, he said, many have also crowded into cages together with no trouble.

The cages were surrounded by security teams whenever state crews used them to remove sea lions, Corrarino said. Armed officers escorted captured sea lions to Point Defiance Zoo and Aquarium in Tacoma, where they were held before being transferred to Sea World and similar facilities.

But no one specifically monitored or guarded the cages at other times, he said.

"That wasn't something we anticipated needing," Corrarino said. He said it may be a moot point anyway if the gates shut and the sea lions died inadvertently.

"It appears as though security may not have been breached," he said.

State officials have suspended sea lion trapping until next year. They will conduct a full review of procedures before they resume any trapping efforts, he said. He said state staff involved in the trapping are troubled by the sea lion deaths, because they had worked hard to avoid any glitches.

"It makes us all sick to our stomach -- the whole thing," Corrarino said. "It's our worst nightmare."

Michael Milstein
Sea Lion Cages Were Outside Bonneville Dam Surveillance
The Oregonian, May 9, 2008

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