Opponents of Oregon and Washington's program to kill salmon-eating sea lions documented branding of 38 California sea lions in Astoria Sunday, including pictures and videos of what they see as an inhumane practice.

Activists with the

said the Astoria trap was so crowded that some animals almost drowned and some went into convulsions after branding. The group's pictures show flames on the skin of some of the sea lions during the branding process.

"It is not humane in any sense of the word, and it's pretty traumatic and horrific for these animals," said Ashley Lenton, a campaign leader for Sea Shepherd's Dam Guardian program.

The

has branded roughly 1,400 sea lions with numbers and letters since 1997 at Astoria's east mooring basin. The branding allows observers from boats, planes and at Bonneville Dam to track the animals throughout their range, ODFW spokeswoman said Jessica Sall said.

Male sea lions follow salmon up the Columbia River and to Willamette Falls during the spring, before returning to mating grounds. The states are

, the first dam on the Columbia, if they've been observed eating salmon and don't respond to hazing.

Sall said an estimated 400 sea lions were in the Columbia on Sunday, which may be a record. The spring chinook run is still early, and no sea lions have been captured or euthanized at the dam.

The Astoria trap, supported by plastic-covered foam, was not in danger of sinking and "the animals were never in danger of drowning," Sall said.

Branding for two to three seconds burns away hair and the top layer of the animals' skin, burning hair follicles so the hair doesn't grow back, Sall said, About half the time, there's a brief flash of flame from burning hair, she said.

The hot branding iron causes pain, but has been long used with cattle and is the most effective way to permanently mark the sea lions, Sall said.

Killing of California sea lions is designed to reduce their consumption of salmon and steelhead, including runs listed under the Endangered Species Act.

Opponents say human actions -- fishing, operating hydropower dams and hatcheries, pollution and habitat destruction -- kill far more salmon than sea lions do.

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