Minnesota and Wisconsin have called a halt to commercial gillnetting in Lake Pepin after some 50 mature sturgeon and paddlefish, two of the region's most vulnerable fish species, were found floating dead in the water near Lake City.
State wildlife authorities said the step is unprecedented but was necessary because both species are making a tentative comeback from near depletion in Minnesota waters, and many of the dead fish were mature, valuable breeding stock.
"They were really, really important animals in those populations," said Kevin Stauffer, area fisheries supervisor for the Minnesota Department of Natural Resources (DNR). Commercial operators "are instructed that they need to avoid killing any of these fish."
The dead fish had marks indicating they were probably trapped accidentally in gillnets along with the carp and buffalo fish that commercial operators were trying to catch.
Tim Adams, a commercial fisherman based in Wabasha, said that such incidents give the business a bad reputation, and that both sturgeon and paddlefish are relatively easy to avoid. "You never want to see that happen," he said. "As a fisherman I'm extremely mad about this situation."
Paddlefish, noted for their long snouts and prized caviar, are threatened in Minnesota, with only small populations known to be left in the Mississippi and St. Croix Rivers. Sturgeon, giant prehistoric fish that don't start reproducing until they are 25 years old, are more widespread, but are still a species of special concern. Minnesota allows only a limited fishing season for them.
Both are wide-ranging fish that have been nearly wiped out by dams, overfishing, development, and pollution.
In the past several decades they have begun a slow recovery in the Mississippi and the Minnesota Rivers, a sign that water quality and habitat are improving, said DNR fish expert Neil Vanderbosch. But that also means there are more at risk of getting caught in commercial nets, he said.