Freshwater ecosystems
Chapter 12 “Freshwater ecosystems” focuses on the study of freshwater organisms via eDNA analysis. It addresses the particularities of the production, persistence, transport, and detectability of eDNA in surface waters. Biomonitoring freshwater ecosystems is imposed by law in more and more countries (e.g., European Council 2000) and the potential of eDNA for this purpose has been identified relatively early. This chapter revisits several studies dealing with eDNA-based analysis of macroinvertebrates (e.g., to track seasonal variation in the ecosystem scale), diatoms (for water quality assessment purposes), aquatic plants (e.g., for invasive species detection), fish, amphibians, and other vertebrates (for species inventories and biomass estimation). Finally, Chapter 12 discusses whether rivers can be good conveyor belts of the biodiversity at the scale of an entire catchment.