Readers Want to Know…
This fall we saw several dead sturgeon on the shores of Lake Superior in Duluth. What’s up?
In September and October the Minnesota Department of Natural Resources (DNR) received reports of 15 dead sturgeon in Lake Superior or on its shores near Duluth and in the St. Louis River estuary. Sea Grant staff found one (see image above) during a beach clean up on the harbor side of Park Point. Another staff member found a 55-inch sturgeon on a Lake Superior beach by his house in Duluth.
John Lindgren, Lake Superior fisheries specialist with the DNR, said he sent samples from three fish for testing to a DNR pathology lab in St. Paul, but results were inconclusive.
Speculation about the cause of death for these unlucky fish includes a lack of oxygen due to higher than normal water temperatures or a disease. Nancy Auer, sturgeon researcher and associate professor at Michigan Technological University said the other most recent fall sturgeon die-off happened in Lake Erie in 2000 due to botulism.
The DNR might be able to solve the fish-death riddle with fresher tissue samples, because the samples they tested were from fish that had been dead for a while. Sturgeon are usually not as active during the winter, but if you see a struggling or freshly dead sturgeon now or next summer, please call the DNR at (218) 525-0852 or 525-0853 and report it.
By Sea Grant Staff