Fidelity of mature Icelandic plaice (Pleuronectes platessa) to spawning and feeding grounds

Abstract

AbstractAbout 2200 plaice (Pleuronectes platessa) were tagged on spawning and feeding grounds off Iceland. The aim was to reveal the migration pattern of mature plaice and to estimate fidelity rates to spawning and feeding grounds. From a total of 183 plaice tagged on the spawning ground and recaptured in successive spawning seasons, 91% of males and 88% of females were recaptured within 30 km of the tagging site. From 55 plaice tagged in the feeding area and recaptured in subsequent feeding seasons, all males and 91% of females were recaptured within 30 km of the tagging location, supposedly after migration to distant spawning grounds as indicated by recaptures in the spawning season. When weighing the number of recaptures with a standardized fishing effort, a minimum level of fidelity to the spawning ground was estimated at 94% for the spawning season one year after tagging and at 72% for the second and third spawning seasons. Fidelity to the feeding area was estimated at 90% after one year and at 100% after two and three years from tagging. The study provides insights into the population structure of Icelandic plaice, relevant to the management and conservation of the population.