Dear MARMAM community, I am delighted to share with you our recent publication stemming from the workshop, "Prospective Discussion on Passive Acoustic Monitoring of Marine Mammals for Descriptor D1 of the Marine Strategy Framework Directive (MSFD)," held during the European Cetacean Society 2023. Title: "Passive Acoustic Monitoring for Assessing Marine Mammals Population in European Waters: Workshop Conclusions and Perspectives" Link: https://www.sciencedirect.com/science/article/pii/S0308597X2300516X _Abstract: _The European Marine Strategy Framework Directive (MSFD, 2008/56/CE) aims to achieve and maintain the 'good environmental status' (GES) of marine ecosystems, including the assessment of marine mammal populations. However, assessing their abundance and distribution is challenging due to their mobility, elusiveness, and difficult data acquisition. This article highlights the role of passive acoustic monitoring as a complementary approach to traditional methods (mainly plane and boat surveys). It also presents the conclusions and perspectives of a workshop organized at the 34th conference of the European Cetacean Society in O'Grove, Spain (18th to 20th April 2023). Building on the rich foundation established by the European Cetacean Society (ECS) in 1987, this society plays a pivotal role in advancing marine mammal research and conservation efforts across European waters. The workshop emphasized the need for harmonization of protocols, indicators, and guidelines to ensure comparability of results. The establishment of a dedicated European working group was proposed to coordinate passive acoustic monitoring efforts, foster collaboration, and share best practices. The workshop concluded that the consolidation of scientific knowledge, the development of common guidelines, and the establishment of a transnational working group would improve the understanding and conservation of these vulnerable species and their habitats. For those interested, feel free to contact me for a PDF or with any questions at mathilde.michel@ensta-bretagne.org. Sincerely, Mathilde Michel PhD student mathilde.michel@ensta-bretagne.org +33 (0)2 21 09 58 89 Lab-STICC – UMR CNRS 6285 -- Logo ENSTA Bretagne <https://www.ensta-bretagne.fr> Logo LabSTIC <https://www.labsticc.fr/en/index/> Mathilde MICHEL *Doctorante*// PhD Student/ *+33 (0)2 21 09 58 89 * *Lab-STICC – UMR CNRS 6285 www.labsticc.fr * ENSTA Bretagne *Grande école d'ingénieurs et centre de recherche* /French State Graduate, Post-Graduate and Research Institute / 2 rue François Verny - 29806 Brest Cedex 9 - France www.ensta-bretagne.fr <https://www.ensta-bretagne.fr>