Biologists Track Bull Trout Travelling 200 Miles Between Hells Canyon and Central Idaho

Salmon and steelhead are famous for their migrations, but bull trout can also travel long distances.

For example, biologists in Idaho documented the remarkable repeat migration of one particular fluvial bull trout (technically a char despite its common name) that is impressive, noted Idaho Fish and Game in a press release.

The term “fluvial” refers to a unique life-history where fish migrate between larger river systems where they spend winters and smaller streams where they spawn.

In January 2018, this particular bull trout was 12-inches long when it was captured and tagged by Idaho Power Corporation biologists in the Hells Canyon section of the Snake River. Small electronic tags are injected into the fish that can later be detected if the fish is recaptured, or some streams have sensors that will detect a tag if a tagged fish swims near it.

The following January, the fish was captured again in the same section of Hells Canyon and measured 16.5 inches in length.

A few months later (May/June), this same bull trout was found in north-east Oregon’s Imnaha River, a tributary to the Snake River in Hells Canyon. Then in July, the fish traveled more than 186 miles to spawn in a small mountain stream in the Salmon River country in Central Idaho.

And that’s not the end of the story; this bull trout kept going. During winter of 2020, the fish was recaptured in the same section of the Snake River in Hells Canyon where it was found in 2019, and was again detected in the Imnaha River in May.

No doubt this bull trout will soon be making its way back to Central Idaho to its mountain spawning grounds, continuing its remarkable journey.

Bull trout occupy cold-water stream and lake habitats in western North America. Once abundant in Oregon, Washington, California, Nevada, Idaho and Montana, bull trout are listed as threatened under the Endangered Species Act in the lower 48 states.

A U.S. Fish and Wildlife Service biological opinion for Columbia River basin bull trout, listed in November 1999, was first completed in the year 2000. Some 16 years later a lawsuit was filed to reinitiate consultation with dam operating agencies and 20 years later the Service is now nearing the final update of a new bull trout BiOp, which also includes Kootenai River white sturgeon.

— CBB, Jan. 30, 2020, USFWS UPDATED BIOLOGICAL OPINION FOR COLUMBIA RIVER BASIN BULL TROUT SET FOR COMPLETION IN JUNE; WILL LOOK AT DAMS’ IMPACTS

The geographic extent of the BiOp, expected to be completed this summer, is all stream reaches and land areas permanently or seasonally inundated by Hungry Horse, Libby, Albeni Falls, Grand Coulee, Chief Joseph, Dworshak, Lower Granite, Little Goose, Lower Monumental, Ice Harbor, McNary, John Day, The Dalles, and Bonneville dams within the high-water mark.

For more on bull trout see:

— CBB, March 26, 2020, USFWS STARTS STATUS REVIEW OF ESA-LISTED COLUMBIA BASIN BULL TROUT AS UPDATED BIOP EXPECTED THIS SUMMER https://www.cbbulletin.com/usfws-starts-status-review-of-esa-listed-columbia-basin-bull-trout-as-updated-biop-expected-this-summer/

— CBB, December 21, 2018, “Upper Columbia Basin Bull Trout Study Finds Small Populations Declining, At Risk,” https://www.cbbulletin.com/upper-columbia-basin-bull-trout-study-finds-small-populations-declining-at-risk/

— CBB, April 6, 2018, “Study: Extirpation Chances Remain High For ESA-Listed Bull Trout In Upper Columbia River Basin,” https://www.cbbulletin.com/study-extirpation-chances-remain-high-for-esa-listed-bull-trout-in-upper-columbia-river-basin/

— CBB, April 22, 2016, “Conservation Groups Sue Over Bull Trout Recovery Plan” http://www.cbbulletin.com/436539.aspx

— CBB, Oct. 2, 2015, “USFWS Releases Final Bull Trout Recovery Plan; Past Legal Challengers Say Plan Still Deficient” http://www.cbbulletin.com/435132.aspx

— CBB, February 25, 2015, “ESA-Listed Columbia Basin Bull Trout’s Genetic Diversity Threatened By Future Climate Change,” http://www.cbbulletin.com/433279.aspx

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