Small-scale fisheries in the South Euboikos Gulf (Greece): Species composition and gear competition

In the present study, we compared the species composition and gear competition of the small-scale fisheries in the South Euboikos Gulf, Greece, from samples collected during 1992-1993 by beach seine (8 mm mesh size, bar length) and gill and trammel nets of different mesh sizes (gill nets: 17, 19, 21 and 23 mm, bar length; trammel nets: 19, 24 and 30 mm, bar length). The sampling depth ranged from 18 to 60 m. Comparisons used univariate and multivariate techniques based on species compositions and the commercial/total (C/T) ratio in terms of weight and number. The results of the various techniques were in close agreement, complemented each other, and suggested that the eight gears used may be aggregated into three main groups: (a) 30 mm trammel net (group I), which is highly selective when compared with all remaining gears; (b) all remaining gill and trammel nets (group II); and (c) beach seine (group III), which is an active unselective gear. These groups differed from each other in terms of species composition and, generally, diversity increased and C/T ratio decreased from group I to group III. The results indicate that banning the beach seine could be essential for conservation of demersal and inshore biodiversity.