Release Of Reared Turbot In Belgian Coastal Waters As A Tool For Stock Enhancement

No abstracts are to be cited without prior reference to the author.

The main objective of this project was to investigate the potential of stock enhancement of turbot within a national context. Therefore 3000 juveniles were cultured until they reached a size which was supposed to be suitable for adaptation to the conditions in the wild. After conditioning to natural prey organisms (shrimp and gobies), approximately 1900 juveniles were tagged with a Petersen disk and released in June 1998 in a closed area near the Belgian coast. After one and half year the total capture rate exceeded 15%. During this period specific biological aspects related to migration, survival, and growth were evaluated by means of captured turbot. Spatial distribution showed that most individuals remained in Belgian coastal waters until October of the year of release. During winter, the turbot migrated to deeper waters (Central North Sea). In spring, the migration pattern showed a return to more coastal waters (The Netherlands, France, Belgium, and the United Kingdom). In addition, data from stomach analysis and growth showed that the released turbot adapted very well to the natural conditions, with a similar growth and feeding pattern as the wild population. This experiment demonstrates clearly the potential of restocking as regards turbot.