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Ecology and salmon related articles

Record Numbers of Chinook Pass Dam

by Jonathan Brinckman
The Oregonian, May 24, 2000

Biologists say that the count at Bonneville is impressive
but that most are not wild

Spring chinook are swimming up Bonneville Dam's fish ladders in record numbers, five times last year's total and the highest count since annual tallies began in 1938, the year after the dam was completed.

Biologists called the spring chinook count, which reached 190,678 on Monday, impressive. But they cautioned that comparing that total with earlier counts is tricky, for two reasons.

First, restrictions on sport and commercial fishing in the lower Columbia River now allow more fish to reach Bonneville, the first dam on the river. Spring chinook harvest levels once approached 100,000 fish. This year, only 162 spring chinook have been caught in the river, according to the Oregon Department of Fish and Wildlife.

Second, when Bonneville was built in the 1930s, all spring chinook reaching the dam were wild. Now more than 90 percent are hatchery-bred.

Still, even considering reduced fishing, spring chinook numbers this year are notable, biologists said. The 10-year average is 62,339.

The Fish and Wildlife Department predicts that more than 201,000 upriver spring chinook will pass the dam by the end of the month. Adding the number of fish caught in the lower Columbia to the Bonneville count, this year's total run will have been exceeded only 10 times since 1938.

"This is a very good return," said Gary Johnson, a biologist with the U.S. Army Corps of Engineers. "It does begin to say that we have done some good things in the Columbia River, both in habitat improvement and in improving conditions at the dams."

Improving ocean conditions, which have brought colder water and more food for salmon, probably also are a factor, Johnson said.

Conservationists are less optimistic. They note that most of the fish passing Bonneville were born in hatcheries and that returns of wild, endangered spring chinook remain below average.

Biologists expect a large spring chinook run again next year because this year's jack count is high. Jacks, which are young males that return from the ocean a year early, are a good indicator of the next year's run. The count at Bonneville through Monday includes 21,600 jacks, nearly eight times the average jack count over the past 10 years.

Jonathan Brinckman
Record Numbers of Chinook Pass Dam
The Oregonian, May 24, 2000

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