Age, Growth and Mortality of Whiting (Merlangius merlangus Linnaeus, 1758) from the Western Black Sea, Turkey

Abstract

The aim of this study was to determine the age and growth, length-weight relationship, sex ratio and mortality rates of the whiting, Merlangius merlangus, in the western Black Sea coast of Turkey. On-board sampling was conducted on the commercial bottom trawl fishery from October 2012 to April 2014. Total length ranged from 6.0 to 25.9 cm, while weight varied between 1.6 and 135.54 g. M. merlangus has a lifespan of 5 years using the ground otoliths reading, but over 60% of fish consisted of 1 and 2 years old. The growth parameters were L infinity=37.05 cm, k=0.10 year-1, and to= -1.63 year for pooled data. Total, natural and fishing mortality were Z=1.19 year-1, M=0.37 year-1 and F=0.82 year-1 respectively according to age-structured analysis. The exploitation rate, E=0.69 year-1, exposed a high fishing pressure on the whiting stock in the studied area. It is believed that this study provides deeper and new conclusions for the management of whiting stock in the western Black Sea.