PRELIMINARY RESULTS OF HATCHERY-REARED SEABREAMS RELEASED AT ARTIFICIAL REEFS OFF THE ALGARVE COAST (SOUTHERN PORTUGAL): A PILOT STUDY

摘要

In 2001 a pilot project offish restocking began using reared juveniles of two native species: the white seabream (Diplodus sargus Linnaeus, 1758) and the gilthead sea-bream (Spams aurata Linnaeus, 1758). Between 2001 and 2004 more than 13,600 juveniles of different sizes (over 7500 white seabreams and 6100 gilthead seabreams) were tagged (FLOY T-Bar anchor FD94) and released on the artificial reef areas, to evaluate the efficiency of restocking. The preliminary results of this ongoing study based on caught fish show that the number of days at liberty ranged from 1 to 340, while the distance traveled ranged from 0 to 67 nmi. However, the mean dispersal distance was < 11 nmi from the release location. A behavioral deficit of the reared seabreams in the use of refuges and feeding was observed during the first week after release. However, thereafter gut content analysis suggested that the reared specimens were able to search for food and feed on the available prey. These results suggest that restocking associated with artificial reefs may be used as an additional tool within an integrated coastal management plan aimed at the enhancement of locally important artisanal fisheries.