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vol-36Biological status and management of Diplodus vulgaris
(Geoffroy Saint-Hilaire, 1817) in Abu Qir Bay, Egypt
Hatem H. Mahmoud*, Amany M. Osman**, Altaf A. Ezzat **
and Adel M. Saleh ***
*National Institute of Oceanography and Fisheries, Alex., Egypt.
**Oceanography Department, Faculty of Science, Alex. University Egypt.
*** Faculty of Marine and Fisheries, Red Sea University, Sudan.
[email protected]
Received 3th January 2010, Accepted 10th March 2010
Abstract
Due to the economic importance of D. vulgaris in Abu Qir Bay (Egypt), this study is concerned to estimate the
biological and population parameters required for proposing a future plan to sustain and manage this valuable fish
resource. Age was determined by using body scales readings. Growth in length and growth in weight were back
calculated. The parameters of Von Bertalanffy growth model were estimated as K = 0.258 year-1, L∞ = 31.3 cm and
to = -0.56 year. The coefficients of total mortality (Z), natural mortality (M) and fishing mortality (F) were 1.049, 0.6
and 0.449 year-1 respectively. The Exploitation rate (E) was 0.428. The Yield per recruit and biomass per recruit
models indicated that, the fisheries status of D. vulgaris in Abu Qir Bay did not reach the limit reference point
(Fmax), thus the fisheries of this species in Abu Qir Bay is not overexploited.
Keywords: Abu Qir Bay, growth, mortality, management, Biological reference points, Sparidae, Diplodus vulgaris.