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Ecology and salmon related articles

Number of Salmon Eaten by Terns Down by a Third

by Mike Lee, Herald staff writer
Tri-City Herald, October 24, 2000

Season-ending numbers for the federal Caspian tern relocation effort at the mouth of the Columbia River show the birds ate 4.4 million fewer salmon this year than last.

That's a decrease of about one-third of the 1999 total.

"This is a very good start," said Bob Willis, chief of environmental resources at the Corps of Engineers in Portland. "On the other hand, these birds are still taking a lot of salmon, so we need to come up with a plan that is going to take the next step."

For the last few years, the Corps and the Fish and Wildlife Service have been trying to move about 20,000 terns toward the mouth of the river where salmon have a better chance of avoiding the birds.

In the 1990s, terns formed the world's largest Caspian tern colony on Rice Island, 230 acres of dredge spoils near Astoria. Despite federal agency efforts, nearly the same number of terns nested on Rice Island last year as in 1998.

Then, earlier this year, environmental groups sued to keep the Corps from harassing the birds to keep them off Rice Island. "It's been very complicated in terms of being able to get anything to happen," Willis said. "Politically, it became impossible to do anything."

Nonetheless, virtually the entire colony of terns nested on East Sand Island this year, apparently convinced by passive measures such as clearing a 4-acre patch of sand on East Sand Island to attract the terns. Tern decoys and tern call recordings also were employed. "What we have been able to prove ... is that we can move these birds without causing any harm," Willis said.

The migration of just a few miles apparently accounts for the drastic decrease in salmon consumption, probably because the waters near East Sand Island provide more dinner options for terns. About 7.3 million salmon were eaten by terns this year, researchers estimate.

Willis and the Caspian tern working group now want to disperse the terns to several sites around the Northwest so they aren't a burden to any single salmon run. Dispersing the birds could save millions of young ocean-bound salmon that are protected by the Endangered Species Act.

The trouble is that no one wants the terns, now infamous for their gluttony. "We haven't seen anything being offered" as tern habitat, Willis said. "This is one of those not-in-my-backyard deals. We need some help."

Related Sites:
www.columbiabirdresearch.org/


Mike Lee
Number of Salmon Eaten by Terns Down by a Third
Tri-City Herald, October 24, 2000

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