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Science Spotlights

A trout being measured by researchers.
We tested the use of ultrasound imaging to nonlethally assess the maturity of resident westslope cutthroat trout. Through this work, we observed the smallest mature female ever documented for this species. 
Arm reaching into stream water with sampling cup
The mountain sucker has been declining in the Upper Missouri River Basin for unknown reasons. To address this uncertainty, a team of Forest Service researchers collected additional genetic data from these fish to find a section of DNA that is completely unique to this new species and developed an environmental DNA assay to detect this unique DNA fragment in water samples with increased accuracy. 
A screenshot of the eDNAtlas Results Map for the Western United States.
Because of its advantages relative to traditional sampling techniques, environmental DNA (eDNA) sampling is being rapidly adopted to address questions about the distribution of species in streams across the United States. The eDNAtlas provides occurrence information for over 50 species from more than 12,000 samples and assists organizations in collecting more samples for specific areas and species. 
A Chinook salmon swimming in water.
New research is helping understand the past and more accurately estimate future salmon recovery potential. Archival “index” redd counts and contemporary redd census data from Central Idaho’s Middle Fork Salmon River (MFSR) offer a glimpse of historical Chinook salmon (Oncorhynchus tshawytscha) spawning and rearing habitat.
A closeup of a gloved hand in a stream holding a funnel attached to a hose.
Environmental DNA methods are highly sensitive and accurate, making them ideal for detecting animals at low densities. However, this tool also comes with its own unique set of challenges when applied to efforts to eradicate invasive species. This research explores the use of eDNA for evaluating invasive species eradication efforts in streams and offers best practices for incorporating eDNA methods into invasive species removal projects.
Sampling streamwater in watersheds of the Hayman Fire
Severe wildfires remove vegetation and organic soil layers and expose watersheds to erosion which can transport large quantities of soil and ash to nearby rivers and streams. But once the burned areas have stabilized, do severe wildfires have any longer-lasting effects on watersheds or water quality? This study follows the Hayman Fire, 2002, Colorado, and shows that yes, there are long-term effects.
National Genomics Center stream water filter setup for eDNA sample collection
The National Genomics Center for Wildlife and Fish Conservation pioneered development of eDNA sampling of aquatic environments at their laboratory in Missoula, MT. The Center has partnered with dozens of National Forests, as well as other state, federal, tribal, and private natural resource organizations to assist in the collection and processing of eDNA samples. Thousands of eDNA samples are collected annually and constitute a rapidly growing...
Effective conservation and management decisions for habitats require information about the distribution of multiple species but such data is expensive to obtain; this often limits data collection to just a few, high-profile species. Environmental DNA (eDNA) sampling can be more sensitive, and less expensive, than traditional sampling for aquatic species, and a single sample potentially contains DNA from all species present in a waterbody. Cost-...
Concerns about climate change effects on cold-water biodiversity sparked broad multi-agency collaborative efforts throughout the American West. U.S. Forest Service research teams led development of massive interagency databases that now enable precise mapping of critical habitats and species distributions in streams flowing through 101 National Forests.
Westslope cutthroat trout, native to the Columbia River and upper Missouri River hybridize with introduced rainbow trout and have been extirpated from large portions of their historical range.
Hybridization between westslope cutthroat trout and both rainbow trout and Yellowstone cutthroat trout is a major conservation concern for the species.  A new broad-scale analysis of hybridization patterns found many pure populations of westslope cutthroat trout in headwaters streams.

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