An excerpt:

Researcher Seth Wenger, the paper's lead author, said cutthroat could see a 58 percent decline in suitable habitat due to warming rivers, altered streamflows and competition from nonnative species.

The study, published in the science journal Proceedings of the National Academy of Sciences, also predicts a decline in introduced brook trout populations by as much as 77 percent, while rainbow and brown trout populations could also decline by an estimated 35 percent and 48 percent, respectively.

The decline of cutthroat trout is of particular significance, Wenger said, because it is the only trout native to much of the West, and is a keystone species in the Rocky Mountain ecosystem. The westslope cutthroat trout - a subspecies included in the study - is Montana's state fish and the focus of numerous conservation efforts.

The 11 researchers who contributed to the study are from Trout Unlimited, the U.S. Forest Service, the U.S. Geological Survey, Colorado State University, and the University of Washington.

Wenger said the paper was based on data collected from nearly 10,000 fish surveys conducted in the western half of Montana, as well as the western parts of Colorado and Wyoming, eastern and northern Idaho, and Utah. The data was used to build statistical models that forecast the decline in total suitable habitat.

The range of cutthroat habitat has already shrunk by more than 85 percent due to competition from introduced species like rainbow trout and brook trout, and two subspecies have already gone extinct.