Population Dynamics and Management of Two-barred Seabream Acanthopagrus bifasciatus in the Red Sea, Egypt

Abstract

The present study is the first study on the population dynamics and management of the Acanthopagrus bifasciatus in the Egyptian sector of Red Sea. A total of 729 specimens were monthly collected from the Egyptian Red Sea during January 2015 to December 2015. Results showed that, the longevity of A. bifasciatus is 9 years in the Egyptian Red Sea and age group three was the most frequent one for combined sexes forming up to 26.61% of the total catch. The age group one was absent in the collected samples and the highest growth in length was observed at the end of the second year of life (24.6 cm) after which the annual increment decreases gradually with increase in age. The growth in weight was isometric. The length at first capture was 25.31 cm with corresponding age 2.22 year. The total, natural and fishing mortality were estimated as 1.99, 0.46 and 1.53 yr-1 , respectively. The exploitation ratio E was estimated at 0.77 indicating a high level of exploitation. The yield per recruit analysis showed that the present level of fishing mortality is much higher than that gives the maximum yield per recruit by about 48% and the reduction of current level of fishing mortality coefficient from 1.53 to 0.8 / y will be associated with an increase in the yield per recruit from 242.71 to 250.56 g (≈3%).