Salmon competition studied - Researchers interested in interplay of wild, hatchery-bred fish

JOHN DODGE THE OLYMPIAN

3/18/03

LUHR BEACH, WA-- Researchers from the Nisqually Indian Tribe are fishing for answers to what happens to juvenile chinook salmon reared in hatcheries and naturally spawning chinook when they leave the river and enter the estuary.

Late last year, the tribe took out man-made dikes on the property near Red Salmon Slough to let the tides roll in and out again like they did 100 years ago.

Do they compete for the same food? Is their stay in the estuary brief or extended? What do they eat?

These are some of the questions the researchers hope to answer.

"The population of young salmon leaving the river is a mystery," said tribal habitat biologist Sayre Hodgson, who heads the research project. "The only way to fill in that knowledge gap is to get out there and count them."

The research team can tell [wild versus hatchery salmon] them apart because the hatchery fish are marked with a clipped fin.

With that in mind, Hodgson and co-workers Craig Smith and Emilinano Perez were out in the estuary Monday, setting hoop nets and tightly knit nets called beach seines. They will repeat the effort twice every other week at several sites around the estuary.

The first beach seine set Monday morning at Luhr Beach near the confluence of McAllister Creek and the Nisqually Reach netted one flounder, more than a dozen sculpin and a mass of seaweed, but no salmon.

Last week, the crew netted nearly 50 wild juvenile chinook.

The hatchery chinook won't be entering the estuary for another few weeks.

The research team can tell them apart because the hatchery fish are marked with a clipped fin.

Whether wild and hatchery fish use the same habitat is important because fisheries managers don't want to unintentionally harm wild fish by releasing hatchery fish that would compete for the same food.

Nisqually River naturally-spawning chinook are part of the Puget Sound chinook stock that is listed as threatened under the federal Endangered Species Act.

The tribe has applied for a $40,000 federal hatchery reform grant to support the tribal field work into the fall of 2003.

"We're hoping we get the money," Hodgson said. Until the grant is awarded, the tribe is footing the bill for the researchers' work.

Of particular interest to the tribe is the field work to determine how well utilized some 31 acres of converted pasture land is by young salmon.

Late last year, the tribe took out man-made dikes on the property near Red Salmon Slough to let the tides roll in and out again like they did 100 years ago.

The move created new estuary habitat.

Estuaries are critical nursery habitat for the young salmon that helps them prepare them for their journey to sea.

The juvenile salmon gathered during the research are released alive back in the water.

"Restoring habitat and finding out how salmon interact with that habitat is vital to our restoration efforts on the Nisqually River," said Georgianna Kautz, tribal fisheries manager.

"To restore wild salmon to the Nisqually River, we need to dedicate ourselves to restoring as much as we can of their habitat."

John Dodge covers the environment and energy for The Olympian. He can be reached at 360-754-5444 or by e-mail at jdodge@olympia.gannett.com.