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Keyword: Salvelinus confluentus

An improved environmental DNA assay for bull trout (Salvelinus confluentus) based on the ribosomal internal transcribed spacer I

Publications Posted on: November 29, 2018
The majority of environmental DNA (eDNA) assays for vertebrate species are based on commonly analyzed regions of the mitochondrial genome. However, the high degree of mitochondrial similarity between two species of charr (Salvelinus spp.), southern Dolly Varden (S. malma lordii) and bull trout (Salvelinus confluentus), precludes the development of a mitochondrial eDNA assay to distinguish them.

Fine-scale characteristics of fluvial bull trout redds and adjacent sites in Rapid River, Idaho, 1993-2007

Publications Posted on: June 22, 2017
From 1993 to 2007, we used single pass, September surveys to locate and measure fluvial bull trout (Salvelinus confluentus) redds in Rapid River, Idaho. Here we describe substrate sizes, redd dimensions, and water depths, velocities, and temperatures within and adjacent to 337 redds. Most (79%) spawning sites had fewer than 20% surface fines ( 60%) in redds.

Climate change, fish, and aquatic habitat in the Blue Mountains [Chapter 5]

Publications Posted on: April 27, 2017
National Forest System lands in the Blue Mountains region support a diversity of important native aquatic species that will be affected by climate change. As part of the Blue Mountains Adaptation Partnership, four of these species (spring Chinook salmon (Oncorhynchus tshawytscha Walbaum in Artedi), bull trout (Salvelinus confluentus Suckley), summer steelhead (O. mykiss Walbaum), and interior redband trout (O. m.

An evaluation of multipass electrofishing for estimating the abundance of stream-dwelling salmonids

Publications Posted on: May 12, 2016
Failure to estimate capture efficiency, defined as the probability of capturing individual fish, can introduce a systematic error or bias into estimates of fish abundance.

Population Genetics of Boise Basin Bull Trout (Salvelinus confluentus)

Publications Posted on: May 12, 2016
We analyzed the population genetic structure of bull trout (Salvelinus confluentus) in the Boise River Basin, Idaho. We determined the influence of contemporary (including anthropogenic) and historic factors on genetic structure, taking into accountexisting data on bull trout habitat patches in this basin.

The range-wide bull trout eDNA project

Projects Posted on: February 04, 2016
The bull trout has a historical range that encompasses many waters across the Northwest. Though once abundant, bull trout have declined in many locations and is now federally listed and protected under the Endangered Species Act. Rocky Mountain Research Station scientists initiated the range-wide bull trout eDNA project in partnership with biologists from more than 20 organizations to create sound and precise information about the distribution of bull trout in thousands of streams across their range.

Detection and range delineation of bull trout using environmental DNA

Science Spotlights Posted on: May 20, 2015
The bull trout is an ESA-listed species that relies on cold stream environments across the Northwest and is expected to decline with climate change. Resource managers from dozens of agencies are charged with maintaining bull trout in thousands of streams, but monitoring this species is difficult. Environmental DNA (eDNA) is much faster, easier, and more sensitive than traditional fish sampling methods and provides an opportunity to better delineate populations of federally threatened species like bull trout.

Diel habitat partitioning by bull charr and cutthroat trout during fall and winter in Rocky Mountain streams

Publications Posted on: May 19, 2015
We used underwater observation to determine diel habitat partitioning between bull charr, Salvelinus confluentus, and cutthroat trout, Oncorhynchus clarki, during fall and winter (0.1-8.3°C) in two Rocky Mountain streams that differed in habitat availability. The majority (>70%) of both species emerged from concealment cover at night, though bull charr exhibited a greater tendency for nocturnal behavior than cutthroat trout.

Role of stream ice on fall and winter movements and habitat use by bull trout and cutthroat trout in Montana headwater streams

Publications Posted on: May 19, 2015
We used radiotelemetry and underwater observation to assess fall and winter movements and habitat use by bull trout Salvelinus confluentus and westslope cutthroat trout Oncorhynchus clarki lewisi in two headwater streams in the Bitterroot River drainage, Montana, that varied markedly in habitat availability and stream ice conditions.

Habitat utilization and diel behavior of juvenile bull trout (Salvelinus confluentus) at the onset of winter

Publications Posted on: May 15, 2015
Underwater observations were used to describe habitat use and diel behavior of juvenile bull trout (Salvelinus confluentus) at the onset of winter (0.8°C) in a second-order central Idaho stream. All fish observed during daytime counts were concealed beneath "home stones" (mean dimensions 32.3 by 21.9 cm) in primarily pool and run habitats. Focal point depths and velocities averaged 57.2 cm and 4.7 cm/s (home stone removed).

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