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GENETIC MARKING HELPS TULALIPS BALANCE WILD, HATCHERY CHUM

MARYSVILLE (12/16/96) -- The Tulalip Tribes are using genetic mass marking techniques to balance the protection of wild fish from the Stillaguamish and Snohomish rivers with the need to produce harvestable numbers of hatchery chum salmon for Indian and non-Indian fishers.

Tulalip marks all chum and chinook salmon before they leave the tribal hatchery, allowing Tulalip managers to distinguish hatchery stocks from the more fragile wild runs during open seasons. That way, the tribe can emphasize its selective fisheries program and target the marked stocks through a variety of innovative management techniques.

"Our local fishing area has always been managed for wild stock production," said Francis Sheldon, Tulalip fisheries manager. "Our hatchery mass marking programs employ the best current science to allow us to protect wild stocks as necessary, while at the same time giving our people access to the hatchery fish produced on the reservation."

Now, because of a ground-breaking genetic mass marking program, the hatchery's chum salmon theoretically won't have to be marked again. By manipulating gene frequencies over a four-year chum cycle, the fish now possess a permanent genetic trait that identifies each as a Tulalip hatchery chum.

"We are using the marked chum in three ways," said Tulalip harvest management biologist Kit Rawson. "We are monitoring natural spawning areas to see if our hatchery fish are straying there, we are using our marked chum as an indicator for Puget Sound fish in Canadian and U.S. mixed-stock fisheries, and we are using the entry timing of the marked chum into our terminal area fisheries in Port Susan, Port Gardner and Tulalip Bay to help us increase the harvest rate in hatchery fish and reduce the rate on local wild stocks."

Fisheries managers have used genetic stock identification for more than a decade to look at chum stock compositions, but until now they've evaluated only natural genetic markings. Yet managers were somewhat frustrated because many hatcheries throughout the Puget Sound, including Tulalip, use chum originating from the same Hood Canal source. "The common origin makes these fish indistinguishable in genetic stock identification studies," Rawson said.

Tulalip is the first hatchery to solve these problems by manipulating gene frequencies to distinguish its own fish.

The tribes did this by tagging fish returning to the hatchery, taking muscle samples and sending the samples to the state Department of Fish and Wildlife genetics laboratory in Olympia the same day. The state faxed the results of genotypes to Tulalip the next morning, so that crews knew which fish to spawn and which fish not to spawn.

Now that its fish are marked, Tulalip fisheries technicians can take weekly tissue samples from chum that are caught by tribal fishermen, from in-river returning salmon and from chum that return to the hatchery. The samples are sent to the state lab for identification and the results are critical in helping the Tulalips manage mixed stock fisheries. This year's fishery sampling and field work, both proceeding with help from the Stillaguamish Tribe and the state, will wrap up by the end of December.

The tribes use run timing, area management and "pulse" fishing to target hatchery stocks. The idea of pulse fishing is that the harvest rate on wild stocks can be minimized by allowing a period of no fishing each week so that wild stocks can pass through while hatchery fish returning to Tulalip Bay accumulate.

"We will continue to seek out innovative ways to protect wild fish while maintaining the viability of our important fisheries based on hatchery runs," Sheldon said.

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FOR MORE INFORMATION CONTACT: Francis Sheldon, Tulalip Fisheries Director, (360) 651-4600; Kit Rawson, Tulalip Harvest Management Biologist, (360) 651-4478; Logan Harris, North Sound Information Officer, Northwest Indian Fisheries Commission, (360) 424-8226.

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