Fishing Technique Known As ‘Gillnetting’ Could Be Linked To Deaths Of Threatened Fish

Wisconsin and Minnesota have temporarily halted a type of commercial fishing called gillnetting in Lake Pepin after almost 50 lake sturgeon and paddlefish were found dead earlier this month.

Both state’s departments of natural resources called for the temporary suspension after 22 paddlefish and 24 lake sturgeon were found dead in an area where commercial gillnetting had been taking place. According to a Minnesota DNR news release, the fish had marks on their bodies that were consistent with gillnetting.

Paddlefish are a threatened species in both states. Lake sturgeon are considered a species of concern, since they’re slow to reach sexual maturity.

Kevin Stauffer, the Minnesota DNR area fisheries supervisor at Lake City, Minnesota, said “pretty much all” of the dead fish were very large adults.

“Losing these individuals out of the population is really, you know, a big loss because of that reproductive potential that they had,” he said.

Stauffer also noted that while the numbers of dead fish may seem relatively small, they’re significant because there aren’t large populations.

“That’s why it’s really important that we minimize this and hopefully eliminate it and still, you know, retain a viable commercial fishery out here,” Stauffer said.

Even though Lake Pepin — which according to the Minnesota DNR is the largest lake on the Mississippi River — is closed to commercial gillnetting, Stauffer said the rest of the river is still fair game.

Gillnetting is a type of fishing that involves fairly long nets with mesh that allows the head of a fish to pass through, entangling the gills when the fish tries to get free.

“Basically, fish get entrapped in that and can’t get out, especially when water temps are warm like they are now. If they’re in there for any amount of time, they basically suffer mortality and can’t be released,” Stauffer said.

He noted that warmer water has less oxygen in it and so when fish get caught, they can’t live as long.

Staffer said it’s understood that occasionally fish like paddlefish or sturgeon will get caught in the gear. He also said operators are supposed to check their gear regularly for those species, and should try try to minimize the time the fish are entrapped and release them if possible.

Stauffer said discussions will continue with the Wisconsin DNR. He said they also want to work with commercial operators.

“I think they’re very aware of this as an issue, and they’re certainly willing to work with us,” he said.