The aim of the present study, which was carried out on 720 individuals between October 1995 and September 1996 in the mid Black Sea region was to estimate some parameters of the population of horse mackerel (Trachurus trachurus L. 1758) including age, size, weight, sex compositions, growth and mortality rates. Ages between 0 and 7 were established in horse mackerel stock. The weight-length relationship was calculated as; W= 0.00759L 3.05 , condition factor 0.843 and the Von-Bertalanffy growth formulas were, Lt= 16.92 (1- -0.3538 (t+2.7938) ) Wt= 47.11 (1-e -0.3538 (t+2.7938) ) 3.05 . Instantaneous total mortality coefficient, natural mortality coefficient, fishing mortality coefficient, survival rates, annual mortality rates, expectation of natural mortality, expectation of fishing mortality and the exploitation ratio were estimated to be Z= 1.55, M= 0.555, F= 0.995, S= 0.22, A= 0.78, v= 0.28, u= 0.50 and E= 0.64, respectively.

The aim of the present study, which was carried out on 720 individuals between October 1995 and September 1996 in the mid Black Sea region was to estimate some parameters of the population of horse mackerel (Trachurus trachurus L. 1758) including age, size, weight, sex compositions, growth and mortality rates. Ages between 0 and 7 were established in horse mackerel stock. The weight-length relationship was calculated as; W= 0.00759L 3.05 , condition factor 0.843 and the Von-Bertalanffy growth formulas were, Lt= 16.92 (1- -0.3538 (t+2.7938) ) Wt= 47.11 (1-e -0.3538 (t+2.7938) ) 3.05 . Instantaneous total mortality coefficient, natural mortality coefficient, fishing mortality coefficient, survival rates, annual mortality rates, expectation of natural mortality, expectation of fishing mortality and the exploitation ratio were estimated to be Z= 1.55, M= 0.555, F= 0.995, S= 0.22, A= 0.78, v= 0.28, u= 0.50 and E= 0.64, respectively.