Over a 20 week period in 2019 Lake Leelanau, Glen Lake, and Walloon Lake participated in a landmark study that involved weekly water sample collections at ten locations on each of the three lakes in the study, followed by qPCR analysis of each sample. This study made three new major findings:
1) Common mergansers migrating in the Spring and Fall (rather than only Summer residents) were a very significant source of parasite transmission;
2) Discovery of new species of swimmer's itch causing parasites emitted by mallard ducks and Canada geese together with
3) Their novel patent snail hosts
These new discoveries were found to be responsible for a significant portion of swimmer's itch cases on North and South Lake Leelanau. Notably Intermediate Lake's inventoried avian population found both mallards and Canada geese in abundance along with their newly discovered patent snail species hosts.