A mark-recapture study of hatchery-reared juvenile European lobsters, Homarus gammarus, released at the rocky island of Helgoland (German Bight, North Sea) from 2000 to 2009

摘要

From 2000 to 2005 about 5400 one-year-old hatchery-reared lobsters (Homarus gammarus) were taggedand released at the rocky island of Helgoland, North Sea. To date, 18% of the different release cohortswere recaptured in the field and 819% of these lobsters were recaptured from the semi-open area of theouter harbour. The recaptured lobsters indicated good development and growth conditions. The smallestberried females caught were 83mmcarapace length and 4 years old. The proportion of cultured lobstersto all measured lobsters captured around the island was 38% in the years 20072009. The populationsize of two cohorts was assessed using the LincolnPeterson method and the estimated survival rateaveraged 30% and 40%. Minimum landing size of cultured lobsters was reached after 47 years. Culturedlobsters showed strong fidelity to their release sites, and thus remained around the island of Helgoland.A basis has been laid to enhance this endangered lobster population by means of a large scale restockingprogramme.