Utilizing aquatic environmental DNA to address global biodiversity targets

Achieving global biodiversity goals requires assessing, attributing and reversing the ongoing, unprecedented biodiversity decline in aquatic ecosystems, and relies on adequate data to inform policy and action. Analysis of environmental DNA (eDNA) has become established as a novel and powerful approach to assess the state and functioning of aquatic ecosystems, and although increasingly implemented by stakeholders its potential is not yet fully tapped. In this Perspective, we review the current state of aquatic eDNA research, focusing in particular on the policy relevance of eDNA and its utility in contributing towards the Kunming–Montreal Global Biodiversity Framework. We summarize key technological developments in eDNA science to measure organismal diversity, its potential for spatial and temporal upscaling to become a key reference for local to global biodiversity action, and the next steps needed to effectively implement eDNA for decision-making and reaching biodiversity targets. Using eDNA to support biodiversity assessment will particularly benefit the understanding of understudied ecosystems and allow the direct calculation of ecological indices and implementation of FAIR (findable, accessible, interoperable and reusable) and inclusive data curation. Important next steps for eDNA require proper method standardization and commonly agreed quality standards, populating reference databases, and overcoming methodological constraints in retrofitting novel eDNA-based approaches to existing biodiversity monitoring approaches. Aquatic eDNA-based technologies offer the potential for universal and standardized biodiversity monitoring. In this Perspective, Altermatt et al. discuss how these technologies can help to achieve the targets of the Kunming–Montreal Global Biodiversity Framework through informing appropriate policy and actions, and describe the next steps required for widespread and equitable use of these technologies.