Large-river fish like paddlefish and blue catfish are in danger.  A University of Wisconsin-Madison study in the journal Frontiers in Ecology and Environment says 60 out of 68 species, or 88 percent, of fish species found exclusively in large-river ecosystems like the Mississippi, Missouri and Ohio rivers, are a conservation concern.

Despite this grim statistic, lead author Brenda Pracheil, a postdoctoral researcher in the UW’s Center for Limnology, reported some good news. Although these fish are found in some of our nation’s largest river systems, their survival is tied closely to the health of smaller tributaries.  These tributaries provide important refuges for large-river fishes, and around the world, these smaller systems are sometimes easier to preserve and protect.

“Tributaries may be one of our last chances to preserve large-river fish habitat,” Pracheil says. “Thinking ‘big’ may not be best approach to saving large-river fish”. “Even though the dam building era is all but over in this country, it’s just starting on rivers like the Mekong and Amazon —places that are hotspots for freshwater fish diversity. While tributaries cannot offer a one-to-one replacement of main river habitats, our work suggests that [they] provide important refuges for large-river fishes and that both main rivers and their tributaries should be considered in conservation plans.”

Read more:  http://www.news.wisc.edu/21813