Brown Trout vs. Brook Trout

A recently published U.S. Geological Survey study examined how native brook trout interact with non-native brown trout under rising stream temperatures.

During the study, which is one of the first experimental studies linking climate change and invasive species biology, researchers found that non-native brown trout limited the ability of native brook trout to utilize warmer stream temperatures.

In contrast, removal of brown trout resulted in the expansion of brook trout into warmer waters.

The brook trout is a freshwater fish species native to eastern North America and threatened by climate change because of its requirement for cold stream temperatures.

Brown trout are native to Europe and have been introduced throughout much of the territory of native Brook Trout.

The research indicates that native brook trout were less resilient to climate change compared to the invasive brown trout because the native fish has less tolerance to higher water temperatures.

The study was published in the Canadian Journal of Fisheries and Aquatic Sciences.

source: U.S. Geological Survey

Snake River Headwaters Restoration

Trout Unlimited (TU) and Jackson Hole Trout Unlimited (JHTU) recently announced the launch of an ambitious new initiative to restore and protect the headwaters of the upper Snake River and its fishery, together with a diverse group of community and agency partners.

 TU’s Snake River Headwaters Home Rivers Initiative will leverage the capacity of the active JHTU chapter and engaged membership in and around Jackson Hole by working with partners to develop and implement high-priority restoration projects to benefit native trout and their habitats.

The Snake River Headwaters HRI will reconnect native trout spawning and rearing habitat by installing fish screens and removing fish passage barriers.

Projects will also restore water quality, habitat, and healthy stream conditions by improving water use and restoring streamflows. Outreach and youth education will actively engage the community and partners in these efforts.

The Snake River Headwaters HRI has been funded by a $100,000 commitment from JHTU as well as the generous support of other private donations.

source: Trout Unlimited

Wisconsin Brook Trout Distribution Predictions

The distribution of brook trout, which requires cold water for survival, could shrink by 60 percent in some Wisconsin streams by mid-century, according to recent climate change models for the Great Lakes region.

Loss of suitable freshwater habitat for brook trout and other popular sport fish species due to climate change are likely to have economic implications for the Great Lakes system.

Recreational fishing opportunities in the region contribute to a multi-billion dollar tourism and recreation industry.

Climate change models for the Great Lakes system are being made by researchers with U.S. Geological Survey, alongside Wisconsin Department of Natural Resources (DNR), Michigan Institute of Fisheries Research, and Michigan State University.

Researchers hope to predict the potential impacts of increasing air temperatures and changes in precipitation on water temperature and flow in freshwater streams that are part of the Great Lakes system.

The models project future distributions for 14 fish species based on known fish locations, their habitat preferences, their adaptability to different water temperatures, existing and future stream conditions, and projected climatic changes.

source: greatlakeslcc.org

Idaho Dutch Flat Dam Removal Could Benefit Steelhead

Dutch Flat Dam was a 10-foot barrier built nearly a century ago to provide drinking water to Troy, Idaho. The dam spanned the West Fork of Little Bear Creek, which ran so dry in summer that nobody thought steelhead survived there.

About a decade ago biologists realized that steelhead do, in fact, survive in such streams. It turns out that steelhead are able to survive dry periods by moving into pools cooled by underground flows.

Over the summer of 2013, local leaders and the Idaho Department of Fish and Game worked with federal agencies to take out the dam so steelhead can again move freely up the West Fork of Little Bear Creek. Crews finished removing the dam’s concrete in early September and are now widening a new course for the creek.

An inventory by Idaho Fish and Game about 10 years ago surprised many locals by finding steelhead throughout the Potlatch River drainage in small streams such as Little Bear Creek that mostly dried up in summer. It turned out that the fish survive the summer in remnant pools cooled by subterranean water.

As word of the steelhead spread, so did enthusiasm for removing the dam and reopening the West Fork of Little Bear Creek, said biologist Bob Ries of NOAA Fisheries. Enthusiasm grew even more when a local resident found steelhead spawning in the creek.

Biologists salvaged almost 180 fish from pools below the dam before the removal began and about three quarters were steelhead, Johnson said. It was the most steelhead they had ever captured in that reach, he said, suggesting that many fish stand to benefit from removal of the dam.

Snake River steelhead were listed as threatened under the Endangered Species Act in 1997. Removing migration barriers and restoring access to high quality spawning and rearing habitat is considered critical for their recovery.

NOAA Fisheries and the Bonneville Power Administration provided $500,000 for the project. NOAA’s funding came from the Pacific Coastal Salmon Recovery Fund, a competitive grant program dedicated to restoring Pacific salmon and their habitat.

For more information, visit: http://www.nwr.noaa.gov/stories/2013/dutch_flat_dam_removal.html

source: NOAA Fisheries