POPULATION DYNAMICS OF Nemipterus japonicus (BOLCH, 1791) IN SUEZ GULF, EGYPT
Mohammed
G.
Desouky
National Institute of Oceanography and Fisheries, P.O. Box
182, Suez, Egypt
Email: mg.desouky@niof.sci..eg –HYPERLINK “mailto: [email protected] “
Abstract
The population dynamics of the Nemipterus Japonicus, in Suez Gulf waters, was studied based on monthly samples collected between Jan 2016- Dec 2016 from El-Atkaa harbor. Age and growth studies based on scales revealed that this species has a maximum lifespan of five years and the mean back-calculated total lengths were 14.3, 18.4, 21.9,24.5 and 26.3 cm at the ages I, II, III, IV and V respectively. Growth was described by the von Bertalanffy growth model as Lt= 27.3 (l-e-0.57(t+0.177)). Estimates of total, natural and fishing mortality were 1.38, 0.57 and 0.81 year-1, respectively. The high value of exploitation ratio (E= 0.59) indicates that this species was harvested at a higher level than the optimum fishing mortality and this fishing pressure should be reduced to obtain MSY. The yield per recruit analysis suggests that the Nemipterus Japonicus stock in Suez Gulf waters needs regulatory measurements to achieve its sustainable development.
Keyword:
Nemipterus japonicus, Suez Gulf, Population dynamics, length-weight relationship, growth, mortality.
