Monofilament gill net and trammel net selectivity for the silver crucian carp (Carassius gibelio Bloch, 1782) in the Egirdir Lake, Isparta-Turkey

The aim of this study was to determine the selectivity of monofilament gillnets with different mesh size for silver crucian carp in E?irdir Lake. In this study, it was investigated that the selectivity of monofilament gillnets with nominal mesh size (stretched) with 32, 40, 50, 60, 70, 80, 90 mm and trammel nets with 100, 110, 120, 130, 140, 150 mm for catching of silver crucian carp. Fieldwork was carried out in two different station of E?irdir Lake, between January-2010 and December-2010 with a three-month period and a total of 4 catching operations. (Share Each Length class Catch Total) (SELECT) method was used to determine the selectivity parameters. In the experiments 1562 silver crucian carp species in ranges of the length between 7.9 cm- 37.0 cm were caught. As a result of calculations made according to the bi-modal model which gave the lowest deviation, for gill nets optimum length (cm) was found as 8.77, 10.96, 13.70, 16.44, 19.18, 21.92, 24.66 for 32, 40, 50, 60, 70, 80, 90 mm mesh size; for trammel nets optimum length (cm) was found to be 24.90, 27.39, 29.88, 32.37, 34.86 for 100, 110, 120, 130 and 140 mm mesh size monofilament trammel nets, respectively.