Transforming marine monitoring: Using eDNA metabarcoding to improve the monitoring of the Mediterranean Marine Protected Areas network.

The creation of Marine Protected Areas (MPAs) is central to the European Union's strategy for protecting and restoring marine environments. However, current research indicates that monitoring of MPAs is insufficient to ensure their protective role. In response, the European Commission encourages the development and adoption of more effective monitoring tools for MPAs. Environmental DNA (eDNA) methods may serve this function, but their use in MPA monitoring and management remains relatively unexplored. The current study addresses this gap by examining the potential for eDNA to enhance monitoring within Mediterranean MPAs, where monitoring challenges are especially severe. We addressed the gap by synthesizing the results of two analyses. First, a systematic literature review examined existing applications of eDNA metabarcoding to monitor marine habitats. From the experiences documented in the reviewed literature, we applied a SWOT analysis (a framework used to identify and analyze strengths, weaknesses, opportunities and threats) to assess the tool's appropriateness for EU monitoring requirements. Second, we probed the tool's suitability for Mediterranean MPAs with a questionnaire on monitoring and other challenges completed by the managers of 29 MPAs in the region. The findings of our SWOT analysis demonstrated that when compared to conventional monitoring methods, eDNA frequently outperformed them or acted as a crucial supplement. We also found that eDNA is suitable for most criteria set forth in EU requirements. Our questionnaire revealed monitoring strategy limitations that eDNA approaches may alleviate. Still, eDNA approaches do have drawbacks which may jeopardize its accuracy and sufficiency. Incorporating eDNA monitoring methods has great potential to enhance protection efforts in MPAs in the Mediterranean and elsewhere. Their successful adoption will require improved coordination among stakeholders and current, comprehensive, and customized recommendations for MPA managers. This will improve the overall functioning of MPA networks and thus support the role of MPAs in safeguarding vulnerable marine environments. • eDNA frequently outperformed conventional monitoring methods or acted as a crucial supplement in marine environments. • eDNA is suitable for most criteria set forth in EU requirements under the Marine Strategy Framework Directive. • eDNA approaches may alleviate monitoring strategy limitations raised by Mediterranean Marine Protected Areas managers. • eDNA approaches need further development to be fully accurate and sufficient. [ABSTRACT FROM AUTHOR]