Dane County wildlife officials are nervous about a small, but potentially disruptive invasive species found in Dane County’s Black Earth Creek: the New Zealand mud snail.

Bob Manwell, spokesperson for the Wisconsin Department of Natural Resources, said the snails range in size from a few millimeters to a grain of rice and can reproduce in huge numbers, potentially causing problems.

“It isn’t clear yet what impact these critters are going to have,” Manwell said.

Dane County Supervisor Leland Pan, District 5, said these snails have put land and water resources at a high risk as they do not have any natural predators in the area.

Pan said anytime a species comes into an ecosystem where they don’t have any natural predators, they can wipe out a large amount of the native species. He said there is no nutritional benefit of these snails and consequently, there is nothing beneficial of their existence for humans.

Manwell said invasive species can pose a large threat by outcompeting naturally-occurring species for resources. Manwell said like most invasive species, the snails are extremely difficult to eradicate, in fact almost impossible, once they show up.

He said the county has been trying to put in place best management practices to share with fishermen, fisherwomen and others who may spend time around the water.

According to Manwell, the goal of these practices is to prevent them from moving from one body of water to another.

“In the case of the mud snail, we don’t have a smoking gun or a way to pinpoint one thing and say this is how it got there,” Manwell said.

Manwell said like most invasive species, the snail probably found its way to Black Earth Creek due to human activity of some kind. He said the mud snails could have been brought by fishing equipment, because most people are unaware that they are transporting species on their equipment.

Manwell encouraged people to clean their boats before they leave one body of water to go to another, ensuring that they do not take any organisms from the first body of water with them.

Manwell said the county will be watching the area closely and expand its surveillance to monitor it.