Shedding light on the river and sea lamprey in western European marine waters

International audienceLampreys are ancestral jawless vertebrates with particularly complex life histories. Population declines resulting from increased anthropogenic pressure have been observed. For semelparous diadromous lampreys, the marine phase remains largely a black box, making targeted management and conservation measures difficult to implement. Here, we collated a database of 168904 hauls from both fisheries-dependent and fisheries-independent surveys between 1965 and 2019. Lampreys were observed in only 254 hauls (20 cm) and occurred in autumn, indicating inshore migration. Our observations provide insight into the ecology of lampreys at sea and highlight study locations and gear types, which may be more pertinent for future research. Greater awareness is needed during surveys to collate catch information on lampreys and improve understanding of their ecology and phenology at sea