Overwintering is a critical part of the annual cycle of animals living at high latitudes, and selection of overwintering sites (hibernacula) is important to population persistence. Identifying the overwintering sites of aquatic species is challenging in areas where water bodies are frozen for significant parts of the year. We tested whether environmental DNA (eDNA) approaches could help to locate them.
We conducted environmental DNA surveys of underwater overwintering sites of the northern map turtle (Graptemys geographica), a species of conservation concern in Canada. We collected water samples under the ice in winter across a mid-sized temperate lake and used quantitative PCR with a species-specific probe to quantify concentrations of map turtle eDNA.