Invasive and highly disruptive zebra mussels were recently found in Bald Eagle Lake north of White Bear Lake, Lake Johanna in Arden Hills and Lake Isabelle near Hastings, the Minnesota Department of Natural Resources has confirmed.

The DNR is conducting follow-up surveys of all three lakes to determine how established the populations are and whether treatment options are possible.

The thumbnail-sized mollusks, which are native to the Caspian and Black seas in Europe and Asia, have fundamentally changed the ecology of lakes across the Midwest since they were brought to the Great Lakes via the hulls of oceanic freighters.

With no natural predators, they strain out and consume tiny, edible material, robbing native fish of the primary link in the food chain. They excrete large quantities of waste that fertilize toxic mats of algae, and when they die their shells wash to shore, collect on lake bottoms and clog pipes.

To slow the spread of the mussels, Minnesota law requires boaters to clean their watercraft and trailers, drain all water and dispose of unwanted bait before launching from shore.