Geographic location of the two lakes and a visual representation of the environmental DNA sampling strategies for Lake Bourget (A) and Paladru (B). Sampling consisted of spatially integrated sub-surface samples collected using high capacity Waterra filters (green lines: 6 transects for Lake Bourget, 2 transects for Lake Paladru), a deep-water sample collected using a Waterra filter in Lake Bourget (green square), and sub-surface point samples collected using Sterivex filters (black dots: 3 samples per transect and deep-water sample).