DOOR COUNTY, Wis. — A Chicago aquarium and some Wisconsin volunteers are studying sucker fish migration patterns throughout Lake Michigan.
The fish species, according to Karen Murchie, plays a vital role in the Great Lakes ecosystem.
“The suckers are an important prey-species for so many game fish. Did you know that they add this buffet of nutrients to the creek that the algae and the invertebrates use that then in turn feed the birds and the bats and other fish?” said Murchie, director of Freshwater Research at the Shedd Aquarium.
Since 2016, she has been searching areas such as Heins Creek, which is near Bailey’s Harbor in Door County, for the sucker fish. During her most recent visit, Murchie spotted 23 sucker fish.
But finding the fish isn’t always so easy. Murchie said sucker fish have left some of the 15 other inland tributaries between Wisconsin, Michigan and Illinois.
She said she believes it was due to a 40-degree temperature drop that happened over the span of a few days in mid-April.
“What they are really looking for is just that right condition where their eggs can develop and hatch because these fish have a bit more of a window. They can be a little bit more selective,” said Murchie.
On the southern end of Wisconsin, Aubrey Fliss volunteers with the Milwaukee Riverkeeper, an organization working to protect, improve and advocate for healthy waterways in the Milwaukee River Basin. As a part of her work, Fliss monitors the sucker fish.
“My background is in environmental policy, so I’ve always been interested in nature and in the environment and taking care of them so with the sucker project, it’s a really cool opportunity for the common person to do research in your background,” said Fliss.
In a recent search in Oak Creek for the study, Fliss said she didn’t see any sucker fish.
Volunteers aren’t the only people working to track the species. Cheryl Nenn of Milwaukee Riverkeeper said they also ask local fishers to report sightings.
“There is a sense that the sucker migration is changing because of climate change, so this study is really set up to be a community-led science study,” said Nenn.
Murchie said their ultimate goal is to determine what conditions lead to the timing of sucker fish migration.
“If the suckers come in and reproduce, their populations might be okay, they might have all the conditions they need to succeed to have more babies but if the other parts of the ecosystem aren’t ready to receive that buffet of nutrients like the caddisfly larva, the algae, etc., if they are not ready to take that up, what would that mean for the rest of the ecosystem?” said Murchie.
Murchie said this is a long-term study. In the process, she and other volunteers said they hope to show people why the fish is so important to the environment.