Puyallup Tribe monitors Bull Trout population

The Puyallup Tribe of Indians is radio tagging a handful of the bull trout to learn more about the small population of fish that inhabit the entire Puyallup River watershed.

Over the summer, tribal staff will attach small radio tags to about a dozen bull trout caught at the White River diversion dam fish trap near Buckley, a tributary to the Puyallup. Tribal staff will follow the fish with a radio telemetry device, tracking their movements.

The small population of bull trout on the Puyallup River, listed as threatened under the federal Endangered Species Act, are difficult to track because they don't migrate in large numbers like salmon.

"We don't know a lot about how these fish live," said Russ Ladley, resource protection manager for the Puyallup Tribe. "We can follow them for about a year after they are tagged. Bull trout have a varied life cycle that is not as straightforward as other salmon species. By tracking them in their habitat, we can pick up on the details that might end up being vital in restoring them."

Bull trout are members of the Pacific salmon family and like salmon they can migrate to saltwater. Bull trout need extremely cold water in which to spawn and grow, meaning most are found high in the mountains. Bull trout live much longer than any other species, with average life spans up to 12 years.

From the data the tribe has already collected, through other fish tracking efforts, there appears to be a main population of bull trout that stays in the icy upper reaches of White River near the rivers' glacial sources. The tribe also has tracked a population that migrates down from the upper reaches to the lower sections of the Puyallup watershed. Yet another smaller population, Ladley theorizes, also migrates out to Puget Sound and lives there for up to four years before returning to spawn in freshwater.

"Bull trout in the Puyallup show the wide ranging life histories that we see in bull trout across the region," Ladley said. "But the population is so small here that if you weren't paying attention, you might not notice it."

Fewer than a hundred bull trout are seen yearly at the White River fish trap, compared to tens of thousands of coho salmon.

Ladley said knowing more about bull trout helps the tribe and the state co-managers protect all species of fish in the Puyallup River watershed.

"Bull trout, chinook, coho and all of the other fish in the river don't live in isolation of each other," said Ladley. "The more we understand about how one fish species lives, the better we understand all species."