Population dynamics and fisheries management of Gilthead sea bream, Sparus aurata (f. Sparidae) from Bardawil lagoon, North Sinai, Egypt | ||
| Egyptian Journal of Aquatic Biology and Fisheries | ||
| Article 5, Volume 15, Issue 1, January 2011, Pages 57-69 PDF (231.86 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejabf.2011.2078 | ||
| Author | ||
| Mohamed Ahmed | ||
| Faculty of Environmental Agricultural Sciences, Suez Canal University, Egypt | ||
| Abstract | ||
| opulation dynamics of Gilthead sea bream, Sparus aurata was studied from a small scale fishery of Bardawil lagoon. 3262 specimens ranged between 11 and 32.9 cm TL and 20 to 592 g total weight, were collected from April, 2009 to November, 2010. The relationship between length and weight was estimated as W = 0.025 L2.813. Age was determined using scales’ reading technique for 865 individuals and the longevity of this species was found to be 4 years. Growth in length and weight at the end of each year was estimated. The growth parameters of the von Bertalanffy equation were calculated as L∞ = 36 cm, K = 0.39 yr-1 and t0 = -1.68 yr. Total, natural and fishing mortality rates were 1.02 yr−1, 0.21 yr−1 and 0.81 yr−1, respectively. The current exploitation rate (E = 0.79) indicates that the stock of seabrea in Bardawil lagoon was heavily exploited. The length at first capture Lc was estimated as 15.54 cm. The length at first maturity Lm of males and females were estimated as 20.5 and 22.8,respectively. The maximum allowable limit of exploitation (Emax) was 0.61 while that at maximum economic yield (E0.1) was 0.499 and maintains 50% of stock (E0.5 = 0.37). The raised Lc to the first sexual maturity (22.5 cm as Lt) would be associated with an increase of Y′/R by 15 % from the current Y′/R at exploitation rates equal Emax= 0.74. Also, raised Lc to 24.5 cm at current exploitation rate Emax=0.79. The results indicate that, for proper management of sea bream catch on Bardawil lagoon, the effort should be reduced or the length at first capture should be raised. | ||
| Keywords | ||
| Population Biology; Fisheries regulation; Sparus aurata; Bardawil Lagoon; Egypt | ||
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