Monofilament gill net and trammel net selectivity for the silver crucian carp (Carassius gibelio Bloch, 1782) in the Eğirdir 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 Eğirdir 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 stations of Eğirdir 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

New approach for codend selectivity: A case study of coastal beach seine for big-scale sand smelt (atherina boyeri) fishery in İznik lake

2-s2.0-85087373938Sand smelt (Atherina boyeri Risso, 1810), which is an exotic species with invasive character, is the third most caught species in the small-scale fisheries among the inland fisheries in Turkey. The fact that it has become an important source of income for the fishermen with low income due to its export potential has led to the maintenance of its stock recently. In this study, the selectivity of coastal beach seine used in the fishing of the species was investigated. A specially designed coastal beach seine with 10 m codend consisting of 4 different compartments was used in the study. Among the compartments of the codend, which was surrounded by a 6 mm mesh cover, in the codend panels mesh with 9, 12 and 14 mm were used. Field studies were carried out on a monthly basis in 4 different stations of İznik Lake in 2014. Selectivity data were collected by the covered codend method and analyzed by means of a logistic equation with the maximum likelihood method. A totally 3053 individuals were caught length ranged from 2.6-11.2 cm and weight ranged from 0.11-11.02 g. The mean L50 values of 14, 12-and 9-mm panels were determined as 6.71, 5.62 and 4.51 cm total length, respectively. It is concluded that 12 mm mesh size panel is suitable for sustainable A. boyeri fishery by beach seine net when considered given by length at first maturity size. © 2020, Central Fisheries Research Inst. All rights reserved.D/2015/A11/P-02/1This study was supported by Republic of Turkey, Ministry of Agriculture and Forest, General Directorate of Agricultural Research and Policies [grant number: TAGEM ??A?SÜD ???? ?-02?/1A] ?an? d ?w? hich was presented in 1stInternational Symposium on Limnology and Freshwater Fisheries.This study was supported by Republic of Turkey, Ministry of Agriculture and Forest, General Directorate of Agricultural Research and Policies [grant number: TAGEM/HAYS?D/2015/A11/P-02/1] and which was presented in 1stInternational Symposium on Limnology and Freshwater Fisheries