Gillnet Selectivity Estimating for Sustainable Stock Management of Endemik Tarek (Alburnus tarichi Güldenstädt, 1814) Population in Lake Van (Eastern, Turkey)

Abstract

This study was carried out to estimate the selectivity properties of gillnets for Tarek (Alburnus tarichi Güldenstädt, 1814) in Lake Van, Turkey. The Tarek is the most fished freshwater fish species in Turkey. The study was carried in 2021 fishing season at seven different sampling locations in the lake. Gillnet selectivity estimated was based on eight different gillnet mesh sizes (i.e. 1.25, 1.6, 2.0, 2.5, 3.1, 3.9, 4.4, 4.8 cm). The SELECT method was used to determine the selectivity parameters. According to the gamma model, optimum modal lengths for 1.25, 1.6, 2.0, 2.5, 3.1, 3.9, 4.4 and 4.8 cm mesh sizes were estimated as 6.61, 8.46, 10.58, 13.22, 16.39, 20.62, 23.27 and 25.38 cm respectively. When considering the minimum landing size, the findings of the study showed that use of gillnets which have less than 3.9 cm mesh size should be prohibited for the fishing of A. tarichi in Lake Van.