Naslov
Temporal and spatial variability of pelagic wild fish assemblages around tuna fish farms in the Eastern Adriatic

Autori
Šegvić Bubić, Tanja ; Grubišić, Leon ; Tičina, Vjekoslav ; Katavić, Ivan

Izvornik
Journal of fish biology (0022-1112) 78 (2011), 1; 78-97

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
aquaculture; seasonal variability; wild fish assemblages; bluefin tuna fish farm; Fish Aggregation Devices (FADs); Adriatic Sea

Sažetak
The abundance and size structure of wild fish aggregated around the sea-cages of two commercial blue-fin tuna farms were assessed and compared with control locations over a period of one year. Tuna farms were located in the Eastern Adriatic, offshore from islands Ugljan and Brač. Fish assemblages were evaluated through visual census using SCUBA bimonthly time spans, on two sites within each farm. Our data suggests that the assemblages of wild fish differ greatly between the control locations and the farms ; 20 species occurred at Ugljan farm and 17 at Brač farm while only 7 were observed at both control locations. Abundance and diversity of wild fish assemblages were greater at the farms in comparison with the control locations. Most abundant families were Sparidae and Belonidae (>80% of aggregated fish). In both farms, abundance and diversity of wild fish were highest during the summer, while winter had the lowest diversity, mainly characterized by the presence of schools of Boops boops and Belone belone. Assemblages at the Ugljan farm significantly differed between the seasons, with B. belone being dominant during the summer and autumn, Oblada melanura in spring, Sardinela pilchardus and Sarpa salpa in winter. At the Brac farm, permanent dominance of B. boops was recorded throughout the year. We also observed that settlement have a significant role in the farm-associated fish assemblages since juveniles and advanced juveniles were common residents at both farms. The majority of species that settled at farms belonged to the sparid family. The results indicate that the aggregations of wild fish at tuna farms are persistent all through the year, but the assemblages’ compositions and size structures of dominant species differ in respect to the location and seasons.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA