Cooperation the answer to prevent import of more aquatic invasives
La Crosse, Wis. — A lesser-known Asian carp snafu in Illinois illustrates the need for NR 40, the Wisconsin DNR’s invasive species rule created in 2009, according to the DNR’s Bill Horns, who spoke at the Upper Midwest Invasive Species Conference at La Crosse Center on Oct. 29.
Horns led a presentation regarding the risks of aquatic invasive species in bait and foreign and game fish shipments, and he wasn’t referring to the highly publicized presence of Asian carp in the Illinois River and a shipping channel that connects it to Lake Michigan, where electrical barrier is hoped to keep the fish from entering the Great Lakes.
No, Horns was talking about 17 old and large Asian carp that turned up in Flatfoot Lake, which is part of Chicago’s Urban Fishing Program. The fish are believed to have been accidentally stocked into the lake, piggybacking on catfish stockings.
“More than anything else, it makes the point that sometimes bad things can happen with the best intentions when people import fish,” Horns said.
Wisconsin’s invasive species rule states that all non-native fish and crayfish are prohibited in the state unless they’re listed on the restricted permissible list. “So that means if a person is bringing in bait or game fish and there’s a freeloader, a hitchhiker … that person is at risk of being in violation of the law,” he said.
Horns said not enough is known about the magnitude or the extent of the risk in Wisconsin.
“We have good reason to believe that it’s possible to bring in non-native fish with loads of bait,” he said. “We don’t know how often it happens, if it happens, where’s it’s happening. But we do know it’s a legitimate risk to consider.”
Horns said the solution is using best-management practices and working with the aquaculture industry to minimize risk.
“It’s about what comes in on accident. That phrase, incidental or unknowing, appears in our invasive species rule now,” he said.
Horns said there are three pathways of interest: bait, foreign fish brought in to feed fish, and game fish brought in to be stocked in state waters.“In all of these cases, the aquaculture industry is an important intermediary,” he said.
At the same time, Horns said the state departments of agriculture and natural resources are limited in regulating the industry. Permits are no longer needed to import native fish.
And he stressed the need to better understand the problem.
“It’s not like we’re seeing hundreds of invasive fish coming in with shipments,” he said.
Horns explained the four categories into which the law divides non-native species.
There are established non-native species such as alewives, smelt, and carp, which have some restrictions, but are not prohibited.
There are non-native aquarium fish, which are not prohibited, but there are only a few ways they can be handled.
Then there are viable non-native fish in the aquaculture industry, which grandfathered non-native fish already in the state.
And there are non-viable, non-native fish, a category created to “give some comfort to the aquarium trade,” Horns said.
“Those are all permissible,” Horns said of the four categories. “Everything else is prohibited, illegal to posses, transfer, or introduce. That means if you’re bringing in bait to a fish farm and you bring along a prohibited fish, it’s illegal if you know it’s there.”
But there is a provision for incidental or unknowing transport if reasonable precautions have been taken, Horns said.
“That begs a lot of questions,” he said. “What is reasonable precaution? How do you prove that it’s incidental or unknowing?”
It’s why guidelines, or best-management practices, were developed for the industry, though those also have garnered criticism from the industry.
Horns said the DNR will continue to work with the industry to the purpose of preventing the introduction of an invasive species.