Population Parameters of Whiting (Merlangius merlangus euxinus L., 1758) in the South-Eastern Black Sea

摘要

Whiting (Merlangius merlangus euxinus L., 1758) is one of the most commonly distributed species in the entire Black Sea coastal waters of Turkey. Population parameters of whiting were studied using 1884 specimens obtained off the coasts of Sinop, Samsun, Giresun and Ordu provinces (Turkey) in 2009-2010. Average annual length and weight increment was 2.41 cm (17.45%) and 14.99 g (75.47%), respectively. Maximum ages were determined as 5 yrs for females and 4 yrs for males. Mean lengths and weights for male and females were calculated as 14.5±0.06 cm; 22.60±0.274 g and 15.1±0.05 cm; 25.74±0.278 g, respectively. Average length and weight for both sexes were calculated as 14.9±0.04 cm and 24.42±0.201 g. Although females were observed as bigger in size in comparison to males, there was no gender dependent statistical difference in length-weight relationship in which W=0.0064 L^3.0441 represents the whole population. Von Bertalanffy growth equation was derived as L_t=38.16 (1-e^{-0,124(t+2,583)}) for females, L_t=26.26 (1-e^{-0.203(t+2,505)}) for males and L_t=33.56 (1-e^{-0,141(t+2,654)}) for both sexes. Instantaneous total mortality, natural mortality and fishing mortality rates were calculated as Z=1.68 yr^-1, M=0.27 yr^-1, and F=1.41 yr^-1. Exploitation rate was E=0.84 yr^-1.