Will we catch fish today? Our grandfathers' responses were usually something along the lines of, 'Probably. I've caught them here before'. One of the foundations of ecology is identifying which species are present, and where. This informs our understanding of species richness patterns, spread of invasive species, and loss of threatened and endangered species due to environmental change. However, our understanding is often lacking, particularly in aquatic environments where biodiversity remains hidden below the water's surface. The emerging field of metagenetic species surveillance is aiding our ability to rapidly determine which aquatic species are present, and where. In this issue of Molecular Ecology Resources, Ficetola et al. () provide a framework for metagenetic environmental DNA surveillance to foster the confidence of our grandfathers' fishing prowess by more rigorously evaluating the replication levels necessary to quantify detection errors and ultimately improving our confidence in aquatic species presence.
Keywords: eDNA; error; natural resource management; occupancy; species richness.
© 2015 John Wiley & Sons Ltd.