"The day was turning balmy, surging toward 80 degrees. But the water gliding down this unusual West Virginia waterway on a sun-drenched August morning remained a cool 62 degrees.

Here, Nathaniel “Than” Hitt, a U.S. Geological Survey biologist, was reasonably sure his team would catch checkered sculpins, a small, mottled fish found only in the Potomac River headwaters of Maryland, Pennsylvania, Virginia and West Virginia.

If they did, it would signal that they had found another refuge from a warming planet.

“This species is only found in the coldest places,” Hitt said. “It needs cold water, and it needs stable flows. This is important because it can tell us about where places are changing and where they’re remaining intact.”

Climate change isn’t just making the air hotter – it’s warming waters as well. Stream temperatures in the Chesapeake Bay watershed have warmed at a rate of about a half-degree per decade from 1960 to 2010, according to a USGS study. . ."