Topic: New publication: Reintroduced European sturgeon uncovered in harbor porpoise stomachs (Eileen Hesse) Dear MARMAM, On behalf of my co-authors and myself, I am very pleased to share our latest publication in Endangered Species Research which reports on the first known predation of reintroduced European sturgeon by harbor porpoises in the North Sea. Hesse, E., Gessner, J., Siebert, U., & Gilles, A. (2024). First record of a Critically Endangered species, European Sturgeon, in the stomach of harbor porpoises from the North Sea. Endangered Species Research, doi: https://doi.org/10.3354/esr01342 Abstract: The European sturgeon Acipenser sturio has been of substantial commercial interest in the past. Today it is considered Critically Endangered, with only one remaining population in Europe. Fulfilling national conservation strategies and aiming for the conservation of biological diversity, Germany has released European sturgeons into their former habitats (Elbe River and its tributaries) as part of experimental measures to restore the population. However, little is known about their biology, sensitivity of life-stages to threats or trophic interactions within their former habitats. Here, we report on the first known predation of reintroduced sturgeons by harbor porpoises Phocoena phocoena and discuss predator-prey interactions in the light of sturgeon conservation. Stomach content analysis on stranded harbor porpoises revealed remains (scutes; modified ganoid scales) of European sturgeon in stomachs of 2 adult harbor porpoises (1.23%). Mean ± SD back-calculated lengths of ingested sturgeons were 26.11 ± 1.90 and 26.49 ± 1.93 cm, respectively, based on dorsal scute morphometrics. To date, no predator-prey interactions between sturgeons and harbor porpoises have been recorded in the North Sea. Future research into the diet of aquatic top predators with overlapping habitats at stocking sites of European sturgeons, transcending national boundaries, will uncover possible conservation concerns, conflicts of species-specific management interests and reintroduction success of European sturgeons. The open access publication is available here: https://doi.org/10.3354/esr01342 Please do get in touch if you have any questions (eileen.hesse@outlook.com). Thank you very much, Eileen On behalf of all the co-authors Eileen Hesse Research associate & PhD candidate ITAW | Institute for Terrestrial and Aquatic Wildlife Research University for Veterinary Medicine Hannover, Foundation eileen.hesse@outlook.com