Harbour porpoise (Phocoena phocoena) in the Wadden Sea World Heritage Site and requirements for trilateral monitoring

Harbour porpoises (Phocoena phocoena) exhibit seasonal movements and potential residency within the Wadden Sea World Heritage Site, as revealed by a comprehensive analysis of data from 1990 to 2020. The study, which integrated telemetry, aerial surveys, strandings, and passive acoustic monitoring, demonstrates that porpoises inhabit both offshore and intertidal waters, with some individuals maintaining limited home ranges year-round. However, significant variability in monitoring methods, frequency, and spatial coverage exists across Denmark, Germany, and the Netherlands, posing challenges to consistent assessment. The research highlights the need for standardized, trilateral monitoring approaches to meet conservation targets aimed at ensuring viable porpoise stocks and habitat quality, as outlined by the Trilateral Wadden Sea Plan.

Scheidat, M., Vrooman, J., Teilmann, J., Baltzer, J., Bie Thøstesen, C., Diederichs, B., Dietz, R., Geelhoed, S. C. V., Gilles, A., IJsseldijk, L. L., Keijl, G. O., Nabe-Nielsen, J., Ruser, A., Schnitzler, J., Sveegaard, S., & Siebert, U. (2024). Harbour porpoise (Phocoena phocoena) in the Wadden Sea World Heritage Site and requirements for trilateral monitoring. Marine Biodiversity, 54(3). https://doi.org/10.1007/s12526-024-01428-6