Environmental DNA Metabarcoding Reflects Fish DNA Dynamics in Lentic Ecosystems: A Case Study of Freshwater Ponds

Abstract

Environmental DNA (eDNA) is a good indicator of fish diversity and distribution in aquatic environments. This study used metabarcoding to assess fish diversity and distribution in two connected ponds during two sampling periods. The eDNA analysis of surface samples displayed differences in the fish communities between the two connected ponds, while within each sampling site the species detected across the two time points were not always the same. These results revealed poor horizontal transport of eDNA between the two connected ponds alongside poor mixing of eDNA for a single pond’s stocked fish. Additionally, water temperature, pH, and total nitrogen were the key environmental factors affecting fish eDNA spatial and temporal distribution. These findings have important implications for designing eDNA sampling strategies in lentic ecosystems; for example, complete fish diversity in a lentic ecosystem cannot be detected by collecting only surface samples and in only one sampling period.

Keywords

• environmental DNA
• metabarcoding
• fish communities monitoring
• eDNA transport