Rising Temperatures Create Problems for Local Trout
The southern Appalachian Mountains have always been known for the abundance of wildlife hidden throughout their range, but research by Patricia Flebbe, assistant professor in the Department of Fisheries and Wildlife Sciences, shows that the region may be losing a significant amount of trout habitat in the future. In a report with Laura Roghair, research associate at the Conservation Management Institute, and Jennifer Bruggink, formerly of the U.S. Forest Service, Flebbe created a projection about future habitat for trout in the southern Appalachians. The report set out to create a model for the minimum elevation at which trout could live in the southern Appalachian region, predict what a rise in temperature may do to trout habitat, and compare the current fragmentation of trout populations with the possible fragmentations resulting from an increase in temperature.
Flebbe looked at the three types of trout present — native brook trout, rainbow trout, and brown trout — in the selected research area in Georgia, South Carolina, North Carolina, Virginia, and Tennessee. “The trout here are at the southern-most extent in eastern North America,” said Flebbe, “but they can live in the southern Appalachians because of cooler temperatures at higher elevations at this latitude.” But owing to global warming, the fish may soon have nowhere suitable left to go.
“The major outcome is that trout habitat would decline dramatically, even with a moderate increase in temperature,” said Flebbe. “More importantly, the habitat would become much more fragmented than it is now.” This fragmentation would lead to a decrease in opportunities for the recolonization of the fish, which makes them more susceptible to extirpation. Additionally, the increase in temperature could alter the spawning cycle of brook trout and rainbow trout, and limit food availability during specific times of the year. These problems only escalate the limitations on habitat, which is already threatened by increasing land development.
When applying projections from two separate global circulation models to their model, Flebbe found that either 53 or 97 percent of trout habitat would be lost by the year 2100. While the severity of problems faced by trout may only occur in the southern region of their habitat, there is much to be lost with the trout’s absence. With the extirpation of trout in the South comes the possible loss of the southern brook trout strain, which exists only in that area. Also, one of the area’s most popular attractions, trout fishing, would become a different experience, dependent on costly management. Finally, the loss of these wild fish would signal a loss in the quality of natural environments in the southern Appalachians.
5/12/09