In Steamy Midwest Streams, Scads of Fish Die Off

Thousands of fish are dying in the Midwest as one of the hottest, driest summers in history dries up rivers and pushes water temps in some spots to nearly 100 degrees. About 40,000 shovelnose sturgeon died in Iowa last week as the water temp hit 97, while Nebraska fishery officials say they've seen thousands of dead sturgeon, catfish, carp, and other species in the Lower Platte River, including the endangered pallid sturgeon. And biologists in Illinois say the heat has killed tens of thousands of large- and small-mouth bass and channel catfish and is threatening the population of the state-endangered greater redhorse fish.

"Those fish have been in these rivers for thousands of thousands of years, and they're accustomed to all sorts of weather conditions," says an Iowa fisheries biologist, who says he's never seen anything like it in his 17-year career. "But sometimes, you have conditions occur that are outside their realm of tolerance." The federal US Drought Monitor shows two-thirds of the lower 48 are under some form of drought; more than half of the nation's counties are natural disaster areas; and some 3,000 heat records were broken last month. "These last two years are the hottest we've ever seen," says a Kansas fisheries official, who expects walleye populations to plummet. But "other species that are more tolerant may take advantage of their declining population." (More Midwest stories.)