PRAIRIE DU SAC, Wis. - The Wisconsin Department of Natural Resources says an invasive fish species has been found in the Wisconsin River.
The Milwaukee Journal Sentinel reports that four bighead carp captured near the Prairie du Sac dam are the latest sign of Asian carp presence in the state. The department also found a fifth fish dead on the shore.
The fish were discovered as part of the department's routine surveys of the sturgeon population.
The department's fisheries experts believe the carp that were found strayed from larger fish populations south of Wisconsin and aren't part of an established population in the state.
Nate Nye is a fisheries biologist with the agency. He says the fish likely reached the Wisconsin River when the water was high in the spring and summer.
"There's nothing stopping them from getting from the Mississippi into the Lower Wisconsin," Nye said in an interview with News 3 Wednesday.
Nye said not only are the fish large, but resilient to extreme conditions, damaging river ecosystems they populate.
"They're prolific breeders, they grow very fast and to very large sizes," Nye said. "They eat very low on the food chain. They eat phytoplankton and zooplankton and that is necessarily for both larval fish of nearly all species, and adult fish of many species."
Timm Zumm, president of the Friends of the Lower Wisconsin Riverway, said the latest news brought him "sadness."
"We work very hard to protect and preserve this treasure we have here, so it's disheartening, of course," Zumm said.
The good news, Nye said, is there's no evidence to show the carp have established a breeding population along the river.
"All the fish that we found are large adult fish and we haven't found any evidence of juvenile or larval fish at this time," he said.
Additionally, Nye said the dam serves as a barrier keeping invasive species from getting into the upper portion of the river.
Zumm said he's hopeful that the fish won't decide to make a home in the Wisconsin River, keeping the lower riverway pristine and teeming with diverse species.
"My youngest son is 50 years younger than me," Zumm said. "I'm hoping from 50 years from now, when he's old as I am, standing right here, this river will be even better than it is right now."
The DNR is asking boaters and anglers to help them prevent the spread of Asian carp and other invasive species along the Wisconsin River.
Boaters should inspect boats and trailers, remove attached aquatic plants and animals, drain all water from boats and equipment and shouldn't move plants or live fish away from a water body, according to the DNR.
Nye said anyone who thinks they caught an invasive carp species should let the DNR know immediately.
"Ensure the fish are killed and report them to the nearest DNR office," Nye said.
Visit the DNR's website to learn how to identify invasive carp species.