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

Type Article
Date 2021
Language English
Author(s) Elliott Sam1, 5, Deleys Noemie1, 2, Rivot E1, 5, Acou A1, 3, Réveillac E4, Beaulaton L1, 6
Affiliation(s) 1 : Management of Diadromous Fish in their Environment OFB-INRAE-Institut Agro-UPPA, 35042 Rennes, France
2 : French Research Institute for Exploitation of the Sea (IFREMER) VIGIES, 44311 Nantes, France
3 : UMS OFB-CNRS-MNHN PatriNat, Station marine du Museum National d’Histoire Naturelle, 35800 Dinard, France
4 : Littoral, Environnement et Sociétés (LIENSs), UMR 7266, La Rochelle Université-CNRS, 17000 La Rochelle, France
5 : UMR ESE Ecology and Ecosystem Health, Institut Agro, INRAE, 35042 Rennes, France
6 : OFB, DRAS, 35042 Rennes, France
Source Endangered Species Research (1863-5407) (Inter-Research Science Center), 2021 , Vol. 44 , P. 409-419
DOI 10.3354/esr01113
Keyword(s) Endangered species, Lamprey, Distribution, Ecology, Growth, Migration, Surveys
Abstract

Lampreys 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 (<1% lamprey presence); 421 sea lamprey Petromyzon marinus and 300 European river lamprey Lampetra fluviatilis were identified. Sizes ranged from 13 to 92 cm and from 14 to 42 cm, respectively. The majority of lampreys (61%) were caught by mobile demersal gear types. The highest presence of both species was recorded within the Greater North Sea, followed by the Bay of Biscay. L. fluviatilis was observed closer to the coast than P. marinus. For both lampreys, there was an increase in size with distance from the coast. P. marinus were predominantly <60 cm and observed from August to February, indicating that these were sexually immature juveniles migrating out to sea. For L. fluviatilis, the majority were thought to be adults (>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.

Full Text
File Pages Size Access
Publisher's official version 11 1 MB Open access
Supplementary material 14 751 KB Open access
Top of the page