TULALIP — The testing of returning salmon to determine whether they are hatchery fish just got easier and less expensive for the Tulalip Tribes.
The state and federal governments donated to the tribes some testing equipment they no longer use to enable the tribes to eventually test their hatchery chum salmon at the reservation rather than send samples to state or federal labs.
Now the Tulalips have received funding to hire two tribal members to do the testing, and they are being trained to use the equipment.
The tribes “definitely received tens of thousands of dollars worth of stuff,” said Adrian Spidle, a fisheries geneticist for the Northwest Indian Fisheries Commission.
The state Department of Fish and Wildlife and the National Oceanic Atmospheric Administration are using DNA testing almost exclusively and no longer use the equipment that tests protein molecules in a process called electrophoresis.
“There was a lot of equipment that we were not going to use,” said Ken Warheit, chief scientist for the fish program at the state Department of Fish and Wildlife in Olympia.
The protein testing method, however, still works fine for the Tulalips in testing their hatchery chum, officials said. The stock from which the Tulalip chum are bred contains unique proteins that are not found in other chum stocks, said Mike Crewson, salmon enhancement scientist for the tribes.
The tribes have been paying $12 per sample tested, which averages out to about $5,000 a year, he said.
“There’s expense for us to do it, too, but it’s so much less,” Crewson said. Plus, “it creates new jobs, they’re good jobs, they’re technical jobs.”
The tribes release between 10 million and 11 million hatchery salmon per year, including about 8 million chum. The hatchery’s purpose is to generate a separate fishery for the tribes so they aren’t catching wild fish and depleting that stock, Crewson said.
Most of the chum salmon return to Tulalip Bay, where they are caught by tribal members. A few, however, stray into streams or the Snohomish River, where they can mix with wild stocks and affect their gene pool.
Determining where the fish come from helps the tribes steer their fishing toward areas with higher concentrations of hatchery fish and fewer wild fish, he said.
The tribes also can adjust their release practices to further imprint the hatchery fish to return to the bay rather than to streams, Crewson said.
“We need to know what those stray rates are,” he said. “We want to keep (the river fish) as wild as possible.”
Before the Tulalips opened their hatchery 30 years ago, they were catching as much as 60 percent to 70 percent wild fish, Crewson said. Now, it’s between 2 percent and 10 percent, he said.
As a result, chinook and coho salmon populations returning to the Snohomish River basin are increasing, he said.
“There’s hardly any wild stock impacts in the region,” he said.
To test for their chinook and coho hatchery fish, the tribes have a different method — checking bony growths in their skulls for markings similar to tree rings. The tribes can give the skulls of each year’s fish distinctive markings by adjusting water temperatures in the hatchery, Crewson said.
The Tulalips plan to experiment with DNA testing and eventually perhaps convert to it, but it’s expensive, with one particular machine’s price tag coming in around $100,000, he said.
Now, having the testing on site helps tribal members see how the process works.
“Right now this is working for us,” Crewson said.
Bill Sheets: 425-339-3439; sheets@heraldnet.com.
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