This paper reports on an unusual mortality event (UME) of healthy, nourished, male Baltic grey seals (Halichoerus grypus grypus) that occurred in the Greifswald Bay at the German Baltic coast in autumn 2017. Findings suggest that the cause of death was bycatch in a fyke net, despite the grey seals being a legally protected species. As a result, the fisheries authority ultimately established precautionary provisions, and fyke nets in Greifswald Bay are now (since 2020) required to have an entrance opening size of no greater than 75cm in circumference, which seems to have been effective to prevent gray seal bycatch in the area. However, gray seal bycatch in other areas continues, suggesting the need for more widespread adoption of preventative provisions.