Invasives online

Episode 7, July 15, 2020

Invasives online

A lot of live aquatic organisms are bought and sold on the internet. A small but concerning percentage of those could potentially become invasive in the Great Lakes region. Species like red swamp crayfish, water lettuce and water hyacinth are prohibited in Wisconsin for that reason. But every so often, these species are still imported into the state and cause an invasive problem.

We visit Ted Judy, a local aquarium hobbyist, to talk about Ted’s Fishroom and the fascinating world of fish breeding and sale. Then, we talk with Robert Stroess, a lieutenant for the Wisconsin Department of Natural Resources, who investigates issues of illegal online aquatic organism trade; for example, the sale of prohibited red swamp crayfish, which are often bought online for crayfish boils. Bonnie and Sydney decide to see just how easy it is to buy aquatic invasive species online.

Because the internet is a relatively new pathway for the movement of invasive species, experts have had to look for new technology to track down invasives online. Erika Jensen talks to us about the web crawler the Great Lakes Commission has used to search the web for species that could cause ecologic or economic harm to the lakes

The hardy red swamp crayfish are native to the Gulf Coast and are considered invasive in many parts of the world. The crayfish are popular for crayfish boils and have been used for education in classrooms. Despite red swamp crayfish being available for purchase online, they are illegal to buy, sell or trade in Wisconsin. 

Water lettuce is popularly used in aquatic gardens, but it poses an ecological threat if it is introduced into natural water bodies. The aquatic plant forms dense mats on the surface of lakes and ponds, making water activities difficult and shading out plants and animals beneath it. 


Smiling woman standing in front of a lake.

Bonnie Willison | Host

Video Producer

What I do at Sea Grant

As the videographer and digital storyteller, Bonnie uses her video and animation skills to showcase the stories of Wisconsin Sea Grant.

Sydney Widell | Host

Student podcast producer

What I do at Sea Grant

Sydney brings her background in geography and journalism to Wisconsin Sea Grant, where she is the co-producer and co-host of Introduced.