Wednesday, March 27, 2013

Study Predicts Climate Change Threatens Trout Habitat

A study by researchers from the U.S. Forest Service, the U.S. Geological Survey, Colorado State University, the University of Washington and Trout Unlimited found that climate change will likely cause a 50% decrease in trout habitat by 2080 in the western United States. Warmer temperatures as well as changes in stream flow and interactions with competing species were all named as contributors to the decline.

The Cutthroat Trout (Oncorhynchus clarkii), the only trout species native to much of the West, is projected to be the most drastically impacted. The Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi), a subspecies, is the Montana state fish and has inspired numerous conservation efforts.

Cutthroat Trout (Oncorhynchus clarkii)

TNACI scientists share a similar focus on the Southern Appalachian Brook Trout (Salvelinus fontinalis) – the only trout species native to Tennessee. Last October, TNACI began a propagation study of the Brook Trout, funded by a grant from the National Fish & Wildlife Federation. Adult brood stock were collected from Hampton Cove Creek and brought back to TNACI where gametes were stripped and eggs were fertilized. The baby brook trout that hatched from the eggs are currently growing strong and will be released in August back into the river from which their parents were caught. This species is sensitive to increasing water temperatures and has a maximum temperature tolerance of 55 degrees Fahrenheit.

Brook Trout (Salvelinus fontinalis)
Reviewers of the climate change study note that Montana’s high elevation and northern positioning may help to buffer some of the effects that may be magnified in other regions. This is particularly significant to TNACI’s work which focuses on conserving freshwater habitats in the Southeast - which may not experience this buffering when it comes to climate change.