Population dynamic parameters of the red mullet Mullus barbatus (Mullidae) in the Arzew Gulf, Algeria

Population dynamic parameters of red mullet, Mullus barbatus (n=592) caught by trawlers operating in Arzew Gulf (Algeria) in the western Mediterranean were studied. Samples were collected between February 2013 and January 2014. Females ranged from 10.9-23.2 cm in total length and 12-149.2 g in weight whereas males length was comprised between 12.6 and 19.7 cm and weight between 21.3 and 99.9 g. The relationship between length and weight was W=0.00167L2.842 (r²=0.850). Growth parameters of the von Bertalanffy equation were: L∞=20.89 cm, K=0.66 year-1, t0=-0.143 year for males, while for females: L∞=250.9 cm, K=0.6 year-1, t0=-0.015 year. Estimates of total (Z), natural (M) and fishing (F) mortalities were: 1.58, 0.8 and 0.79, respectively and the estimated exploitation ratio 0.5 indicating that the resource is being exploited at its limit in this area. The virtual population analysis of M. barbatus by VIT software showed that the number of recruits per year was estimated at 4447304.6 individuals, balanced total biomass was estimated at 168 486 tons, the gains are represented by recruitment 51.71 tons (30.69%) and growth 116.76 tons (69.31%), losses are represented by natural mortality 98.48 tons (58.45%) and fishing mortality 70 tons (41.55%). The current yield per recruit was estimated to Y/R=15.74 g and maximum sustainable yield can be reached by increasing the current fishing effort to stabilize it at MSY=17.91 g.