Above-average fluctuations in rainfall, snowmelt and runoff in the lower Missouri River are complicating U.S. Fish and Wildlife Service efforts to recover endangered pallid sturgeon, one of the continent’s largest freshwater fish. Unusually low water levels in 2004 and 2006 have been followed by record high levels since 2007, say scientists. The Service is working with the U.S. Geological Survey (USGS) through the National Climate Change Wildlife Science Center and Science Support Partnership Program to anticipate how a range of such changes may impact pallid sturgeon recovery efforts throughout the region, encompassing Missouri, Nebraska, Iowa, Kansas and South Dakota.
“Essentially we are trying to build a more comprehensive picture of how the fish may react [to changes in water level and temperature that might be associated with a changing climate],” said Mark Wildhaber, USGS research ecologist.
For centuries, rivers in the West and Midwest teemed with these great fish, which can weigh as much as 60 pounds, and have distinctive long, flat snouts. Then engineers dammed and straightened the Missouri, eliminating tree snags where sturgeon would feed, hide and spawn. Overharvesting by commercial roe fishermen further stressed the species, listed as endangered in 1990. Scientists have only recently begun to factor climate change into the recovery equation.
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