Authors: İSMET BALIK, HIDIR ÇUBUK, REMZİYE ÖZKÖK, RAHMİ UYSAL
Abstract: This study was conducted between March 2001 and February 2002 to investigate the size composition, growth characteristics and stock size of the pikeperch, Sander lucioperca (L. 1758), population of Lake Eğirdir. In the population, the rate of individuals more than 2 years of age and 20 cm was very low. The average length and weight of the commercial catch were also low. The length-weight relationship and von Bertalanffy growth equation were W = 0.006 L^{3.148} and L_t = 95.4*(1-e^{-0.0841(t+1.5638)}), respectively, and the average condition factor was 0.992. This last value is higher than those reported in other studies on the pikeperch population of this lake in the last 30 years. The total mortality and exploitation rates were 71.9% and 0.85, respectively. During the study, the annual catch of pikeperch was 50.2 t. In the lake, the stock of pikeperch over 14 cm in length was estimated as 601,299 individuals and 53.4 t in biomass. The present fishing effort should be decreased by 60% for maximum sustainable yield (MSY). In this way, 82.8 t of pikeperch could be obtained from the lake and the biomass of this species in the lake would be increased up to 350 t.
Keywords: Pikeperch, size composition, growth characteristics, mortality rates, stock analysis
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