Stock Management Implication of Caspian kutum (Rutilus frisii kutum Kamensky, 1901) in Iranian Waters of the Caspian Sea

Recently the previous Caspian ecosystem is in a catastrophic condition which caused changes in the absolute and relative abundance of the commercially important Caspian kutum (Rutilus frisii kutum) in Iranian waters. The paper presents estimates of yield-per-recruit and spawning biomass-per-recruit under various harvest strategies of Fmax, F0.1, F30%. It proposes a method for estimating acceptable biological catch (ABC) that accounts for large differences in the quality and quantity of information and available data. The current average Y/R (with F=0.61/y, and tc=3.2 y) was 218.3 g per recruit, which indicates that the fishery is operating below the maximum Y/R at 236.9 g when tc = 3.5 y. The Y/R was the highest at Fmax and F0.1, when tc = 4 y (244.8 g and 214.2 g), respectively. The F30% value was 0.85/y at tc of 4 y with the SB/R of 338.3 g. The Fcurrent (0.61/y at current tc is 3.2 y) is higher than the corresponding reference points, F0.1 (0.47/y) and F30% (0.46/y). The ABC of kutum was estimated at 7,850 mt in 2009-2010.