Age, growth and mortality of anchovy Engraulis encrasicolus in the south-eastern region of the Black Sea during the 2010-2011 fishing season

Abstract

In this research age composition, sex-ratio, growth, survival, mortality and exploitation rates were determined in the southeastern Black Sea region of Turkey during the 2010-2011 fishing season. Anchovy in the age group 2 was the most abundant (64.06%), followed by age groups 1 (33.12%), 3 (1.80%) and 0 (1.02%). Mean length and weight of the total sample, males and females, were 11.63 +/- 0.02 cm, 9.98 +/- 0.04 g; 11.39 +/- 0.03 cm, 9.40 +/- 0.07 g; and 11.98 +/- 0.02 cm, 10.73 +/- 0.05 g, respectively. The mean condition factor was CF = 0.63 and the sex composition was 61.27% female, 34.40% male and 4.33% unidentified. Equations describing the relationship between length and weight, age and length, and age and weight were derived as W = 0.011 x L-2.742, L-(t) = 16.368*(1-e(-0.425*(t + 1.35))) and W-(t) = 23.516*(1 -e(-0.425*(t+ 1.35)))(2,747), respectively. The survival (S), instantaneous total mortality (Z), annual mortality (A), natural mortality (M) and fishing mortality (F) rates were found to be S = 5.8%, Z = 2.84 yr(-1,), A = 94.2%, M = 0.66 yr(-1), and F = 2.18 yr(-1), respectively. The exploitation rate was calculated as 0.77, which is higher than the optimum exploitation level.