All of the trout native to South Carolina's mountain streams will disappear if climate change increases air temperatures by 7 to 8 degrees, according to information presented at a global warming forum Thursday in Columbia.
Because South Carolina has relatively few mountains higher than 3,000 feet, native brook trout in the Palmetto State are most at risk of dying off from rising global temperatures, Trout Unlimited biologist Damon Hearne said. The same fate holds true for Georgia's mountains, also at the lower end of the Appalachians, he said.
"Almost all of the areas with brook trout are going to be affected by climate change and warming," he said, showing maps of trout streams in the hills of Oconee, Pickens and Greenville counties. "Brook trout here are at the margins already."
The rise in air temperatures would have a corresponding impact on water temperatures, he said. Trout can't live in water with temperatures higher than 68 to 72 degrees Fahrenheit.
Hearne said the question is how long it will take for air temperatures to rise by 7 to 8 degrees. Some climate models say that could take anywhere from 50 to 100 years if global warming continues as many scientists expect. Hearne based his comments on research by Trout Unlimited and government climate models.
Trout Unlimited is a national organization that works to conserve, protect and restore North America's watersheds for the popular game fish.
The presentation came at a luncheon backed by the S.C. Wildlife Federation. The global warming forum included climate expert Gregory Carbone from the University of South Carolina; Clemson University wildlife ecologist Drew Lanham; and S.C. Department of Natural Resources duck expert Dean Harrigal.
The meeting was held to show the effects of global warming as Congress debates stricter standards for greenhouse gas pollution. It comes in the same week that world leaders are meeting in Copenhagen, Denmark to discuss reducing greenhouse gas emissions, which contribute to global warming.
Brook trout are found in the east from Minnesota and New England to Georgia. But a distinct strain of brook trout, which fishermen have long said have brighter speckles, is native only to the Southern Appalachians, according to the National Wildlife Federation and Duke University.
Only 16 miles of streams in South Carolina contain brook trout, and only 4 miles contain the strain native to the southern Appalachian mountains. Overall, South Carolina has about 200 miles of trout streams, but most of those are populated by brown and rainbow trout that were brought to the state years ago.
Hearne, Trout Unlimited's southeastern land protection coordinator, said the nation - and the world - should take aggressive steps to stop greenhouse gas pollution that contributes to global warming and threatens fish such as trout.
"Hope relies on trying to curb emissions so we minimize how much the temperature increases are," Hearne said.
He said states may be able to protect some native trout, even with rising temperatures, by making it easier for the fish to reach higher elevations and cooler water. That can be done, for instance, by removing or redesigning dams and culverts under roads, which can act as barriers to fish seeking to swim upstream.