Stock Management Implication of Caspian kutum (Rutilus frisii kutum Kamensky, ۱۹۰۱) 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, F۰.۱, F۳۰%. 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=۰.۶۱/y, and tc=۳.۲ y) was ۲۱۸.۳ g per recruit, which indicates that the fishery is operating below the maximum Y/R at ۲۳۶.۹ g when tc = ۳.۵ y. The Y/R was the highest at Fmax and F۰.۱, when tc = ۴ y (۲۴۴.۸ g and ۲۱۴.۲ g), respectively. The F۳۰% value was ۰.۸۵/y at tc of ۴ y with the SB/R of ۳۳۸.۳ g. The Fcurrent (۰.۶۱/y at current tc is ۳.۲ y) is higher than the corresponding reference points, F۰.۱ (۰.۴۷/y) and F۳۰% (۰.۴۶/y). The ABC of kutum was estimated at ۷,۸۵۰ mt in ۲۰۰۹-۲۰۱۰.

کلیدواژه ها:

Acceptable biological catch ، Reference point ، Rutilus frisii kutum ، Spawning biomass per recruit ، Yield per recruit