Contrasting patterns of biodiversity across wetland habitats using single-time-point environmental DNA surveys

Abstract

Wildlife surveys are central to the conservation and restoration management of wetland habitats; however, the often laborious and costly nature of traditional survey methods can constrain the spatial and temporal extent and replication of survey efforts. Environmental DNA (eDNA) technologies now provide the opportunity to reduce some of these limitations, but applications in temporary and permanent freshwater marshes and meadows (herein referred to as ‘wetland habitats’) remain limited. This study investigates the performance of single-time-point eDNA surveys for characterizing fish, amphibian and bird assemblages of wetland habitats in south-eastern Australia. Comparisons were made between coastal and inland wetlands, between wetlands of varying condition and between eDNA and traditional surveys. Findings show that eDNA surveys can provide comprehensive descriptions of faunal assemblages associated with wetland habitats, with resolution similar to that provided by traditional survey approaches. Analyses also revealed significant differences in patterns of biodiversity between wetland types (coastal vs. inland) but not between wetland habitats varying in condition. Overall, this study confirms that eDNA surveys provide a reliable option for undertaking wetland biodiversity assessments aimed at improving biodiversity data coverage for otherwise data deficient wetlands.