First release of hatchery juveniles of the dusky grouper Epinephelus marginatus (Lowe, 1834) (Serranidae: Teleostei) at artificial reefs in the Mediterranean: results from a pilot study

摘要: A pilot experiment of stock enhancement based on the release hatchery-reared juveniles dusky grouper, Epinephelus marginatus, was carried out at two artificial reefs located 0.9 km offshore south-western Sicilian coast (Central Mediterranean). The fish assemblages inhabiting were characterized using underwater visual census (UVC) surveys. Despite some differences in species richness, diversity and abundance, both provide suitable feeding resources shelter opportunities for settlement grouper juveniles. total 95 juveniles, which 3 4 years old, released. No stress-related effects swimming or behaviour observed during step by transportation to sea-bottom 20 m depth. After release, several groupers showed very low reactivity; freezing schooling most common behaviours. sighting rate after one month UVC surveys 15.7% 20% reefs. effect size survival observed. Some not recorded pyramid but elsewhere same reef, demonstrated their ability move around reef. extent dispersal released largely exceeded area encompassed reefs, shown recaptures tagged local fishermen up 13 from site. This result provides a first insight into potential hatchery reared marine ranching conservation purposes.