In this study,
gillnet selectivity of saddled seabream (Oblada melanura), common
two-banded seabream (Diplodus vulgaris), annular seabream (Diplodus
annularis) and Mediterranean horse mackerel (Trachurus
meditterraneus) which were caught by bogue gillnets with 20, 22, 23 and 25
mm mesh size (nominal bar lenght) have been determined. Fishing trials were
carried out in Noth Aegean Sea from March 2008 to February 2010. Selectivity
parameters were estimated using the Select method. Most suitable selectivity
models were calculated as log-normal for saddled seabream (O.
melanura) and annular seabream (D. annularis), bi-modal
for Mediterranean horse mackerel (T. meditterraneus) and
common two-banded seabream (D. vulgaris). Optimum catch
lengths for 20, 22, 23 and 25 mm mesh size were 11.15, 12.27, 12.83 ve 13.94 cm
for annular seabream (D. annularis), 11.26, 12.39, 12.95 and
14.08 cm for common two-banded seabream (D. vulgaris),
15.3, 16.83, 17.59 and 19.12 cm for saddled seabream (O. melanura)
and 26.68, 29.35, 30.68 and 33.35 cm for Mediterranean horse
mackerel (T. mediterraneus), respectively.
These findings may help us to understand that using higher than 23 mm stretched
mesh size with gillnets which have been used for commercial bogue fisheries
around north Aegean Sea is important for sustainability of fisheries.