EuRockFish pilot: “Toward a European Rocky reef Fish Monitoring Network” (funded by Biodiversa+)

Gaëlle Legras^1,2, N. Prasil-Delaval^1,2, M. Delesalle^1,2, A. Ring Kleiven^3,4, K. Martinez-Swatson^3,4, P. Kleiven^3,4, P. Staehr^5,6, B.Robinson^5,6, Q. Ternon^1,2, L. Guérin^1,2, V. Danet^1,2, A. Cuadros^7,8, S. Díez González^7,8, A. Cebeci^9,10, R.C. Öztürk^9,10, M. Alemdağ^9,10, S. Firidin^9,10, G. Rilov^11,12, N. Stern^11,12, S. Zilberman^11,12, A. Morov^11,12, G. Raanan^11,12, Y. Sonego^11,12, M. Haim^11,12, S. Nazarova^11,12, O. Bianchimani¹³, T. Estaque¹³, P. Thiriet^1,2

¹French Biodiversity Agency (OFB), France - ²UAR PatriNat (MNHN-OFB-CNRS-IRD), France - ³Norwegian Environmental Agency (NEA), Norway - ⁴Institute of Marine Research, Norway - ⁵Ministry of Environment of Denmark, Denmark - ⁶Aarhus University, Denmark - ⁷Spanish Biodiversity Foundation, Spain - ⁸Insituto Español de Oceanografia, Spain - ⁹Ministry of Agriculture and Forestry (TAGEM),Turkey - ¹⁰Karadeniz Technical University, Turkey - ¹¹Ministry of Environmental Protection, Israel - ¹²Israel Oceanographic and Limnological Research, Israel - ¹³Septentrion Environnement, France

Marine policies (eg. MSFD, OSPAR, HELCOM…) and biodiversity management frameworks require monitoring and assessment of the ecological status of European rocky reef fish . However, observational methods used throughout Europe are heterogeneous, and some traditional approaches (e.g., nets and pots) are invasive, causing fish mortality and impacting sensitive habitats. This has led to an increasing demand for non-invasive and interoperable methods for fish monitoring and ecological status assessments. To address these needs, the Biodiversa+ EuRockFish pilot (a pilot species monitoring study funded by Biodiversa+, 2024-2025) aims to test and assess the complementarity between two traditional visual methods (visual census by scuba diving and video) and an innovative approach using environmental DNA (eDNA) in different environmental conditions at the pan-European level. Ultimately, the project seeks to establish a methodological framework including unified and standardized protocols according to the required metrics and encountered environmental conditions. By reducing methodological variation among researchers, our ambition is to support the need of policy strategies for monitoring rocky reef fish communities and, more broadly, to address large-broadscale ecological questions.
Here, we will present the implementation of EuRockFish, including its sampling design and tested protocols at the pan-European level, as well as the preliminary results obtained to date.