U.S. drought taking heavy toll on fishing industry – ‘Unheard of’ river temperatures causing mass fish kills
By Alyce Hinton; editing by Jim Marshall
27 July 2012 (Reuters) – The drought and extreme heat wreaking havoc across the U.S. farm belt is killing fish by the thousands in lakes and rivers and could pose a problem to migrating ducks and other waterfowl if it stretches into the fall, officials said. Authorities are tallying up the losses which could run into the millions of dollar as the worst drought in 56 years expands, devastating the corn and soybean crops and forcing ranchers to cull their herds due to scorched pasture. “Nationwide we are talking tens of millions to hundreds of millions (of dollars in losses). It just depends upon how long it lasts and how widespread it becomes,” said fisheries biologist Dan Stephenson of the Illinois Department of Natural Resources. “If this drought persists into fall, when the duck and other waterfowl pass through on their way south, there could be a larger problem,” Stephenson told Reuters. In Iowa, losses were estimated at $10.1 million after 37,000 fish were found dead along a 42-mile stretch of the Des Moines River from the dam in Eldon to the Farmington Bridge in the northeast of the state. “Temperatures were extremely high … I mean 97 degrees (Fahrenheit; 36 Celsius) is essentially unheard of on this stretch of the river and it’s certainly higher than anything I’ve ever seen,” says fisheries biologist Mark Flammang of the Iowa Department of Natural Resources. Flammang said the majority of fish killed in Iowa were shovelnose sturgeon, with a value of $116.20 per lb based on guidelines from the American Fisheries Society. […] Fish are particularly susceptible to even subtle changes in their environments. Oxygen levels usually fluctuate during the day and night depending on temperature and other factors. But the hot weather heated some waterways to between 85 and 90 degrees, forcing oxygen levels in the water down to a degree that caused fish to suffocate. […]
