Stock assessment of Salmo trutta Linnaeus, 1758 in tributaries of the Taleghan River, Southern Caspian Basin

This study aimed to study the survival rate and stock assessment of Salmo trutta in Taleghan River using regional sampling and Binns and Eiserman methods (developped for assessment of trout fishes in the streams). For this purpose, the samplings were performed in 40 stations, but S. trutta was found only in three tributaries of Grab, Gateh-Deh and Deh-Dar in the Taleghan River using regional sampling and Binns and Eiserman methods. Therefore, the stock assessment study was delimited to these tributaries. Based on the results, the survival rate was calculated in the first –third year as 0.21, 0.6 and 0.25. Regional sampling method estimated biomass values of 3.98, 9.16, 0.84 kg/km for this fish in Grab, Gateh-Deh and Deh-Dar streams and Binns and Eiserman method estimate biomass values as 18.97, 32.89 and 12.39 for these three studied streams indicating a limited distribution and lower abundance of S. trutta stocks in the Taleghan River.