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

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