Sea lamprey

Common Name: Sea lamprey

Scientific Name: Petromyzon marinus

Descrption: The sea lamprey (Petromyzon marinus) is one of the largest parasitic fish that migrates marine and fresh waters and ectoparasite species. At the end of the winter, it leaves coastal waters to migrate upstream, at night, into rivers over 500km from the sea. Reproduction takes place between the end of April and the end of May in vast semi-circular nests called redds. The females release a large number of eggs which become lodged between the redd pebbles and die shortly after spawning. Larvae of 5mm length hatch after 10-15 days and immediately go in search of sheltered marginal sandy-silt zones where they stay burrowed for 5 to 7 years. Metamorphosis takes place at the end of the summer when the juveniles swim downstream at night during the autumn and reach the sea by the winter. Their marine growth phase is short and lasts around 2 years, by parasiting various fish species (shad, herring, pollock, salmon, mullets, cod, haddock, basking sharks).

OSPAR Regions where it occurs: I, II, III, IV

OSPAR Regions where under threat and/or in decline: I, II, III, IV

Why is this feature included on the OSPAR List?

What protective measures and actions has OSPAR committed to taking?

What actions have been implemented by OSPAR?

What is the latest status of the feature?

The status assessment describes the latest changes in distribution, abundance and range of the feature, as well as any changes in the threats and pressures impacting the feature. The status assessments are updated regularly and inform OSPAR’s consideration of the effectiveness of the measures and actions that have been adopted and implemented by Contracting Parties.