GROWTH, MORTALITY AND YIELD PER RECRUIT OF MUGIL CEPHALUS IN BARDAWIL LAGOON, NORTH SINAI, EGYPT
Hassanen, G. D. I.1.; Salem1, M. And M. A. El Aiatt2
1. Faculty of Environmental Agricultural Sciences, EL-Arish, Dept. of Fisheries Resources and Aquaculture, Suez Canal University.
2. General Authority for Fish Resources Development
Received 10/ 11/ 2012 Accepted 26/ 12/ 2012
Abstract
Growth, mortality and yield per recruit of Mugil cephalus
were studied from a small scale fishery of Bardawil lagoon. 620 specimens (18.22 to 46.73 cm total length and 103.5 to 1235 g total weight), were collected from April to December, 2010 (one fishing season). The relationship between length and weight was W= 0.0303*L2.6723. Age was determined by scales where age groups 0 to 5 years. Growths in length and weight at the end of each year were calculated as 20.24, 29.02, 36.43, 41.46 and 45.65 cm for the 1st, 2nd, 3rd, 4th and 5th year of life respectively. The growth parameters of von Bertalanffy equation were calculated as (L∞= 59.9 cm, K = 0.255 year-1 and t0 = -0.601 year). Growth performance index (φ′ = 2.96). Mortality rates were 0.87 yr−1, 0.33 yr−1and 0.54yr−1 for total, natural and fishing mortality respectively. The currently exploitation rate E = 0.62. The length at first maturity (Lm) was estimated at 32.8 cm (2.58 year) for males and 34.9 cm (2.77 year) for females while the length at first capture (Lc) as 33.4, (2.63 year)). The results of age at first capture and the current exploitation rate indicated that the small fish are caught at higher fishing effort level. The current mesh size should be increased in order to increase the
Tc to 3 year which achieve the highest yield at current fishing effort. Thus, the current effort of M. cephalus should be stabilized at increase of Tc to 3 year and if possible should be reduced.
Keywords: Age, growth, yield per recruit, Mugil cephalus,
Bardawil lagoon. Egypt.
Corresponding author: Tel. 0160016096
E-mail: [email protected]
