Spawning site fidelity in Baltic Sea turbot (Psetta maxima)

Tagging of more than 2000 turbot in the eastern Gotland basin in the central Baltic Sea revealed strong spawning site fidelity. Only 4 out of 653 recaptures were made outside the Gotland area and 95% of recaptures, 1–4 years after tagging, were found less than 30 km from the original tagging site. Within the summer spawning season turbot were almost stationary and 95% of them were recaptured less than 16 km from the tagging site. During the spawning they dwelled close to shore at a mean depth of only 5 m while migration to deeper areas was evident in the feeding season. Indications of differences in the spawning behavior between sexes were found together with a positive correlation between recapture probability and body length. The revealed spawning site fidelity has implications for management practices of turbot in the Baltic Sea.