The present study was conducted in four coastal stations of Sistan and Baluchestan province in two seasons (before and after Monson), during 2021 to 2022. A total of 2779 Babylonian snails specimens (1489 males, 1290 females) were biometrics as well as a number of these were described (about ten percent of the specimens). The mean length and weight of male and female snails were 36±5, 32±5 mm and 14 ± 6, 10 ± 4 g, respectively. Relationship between length (mm) - weight (g) female specimens W = 0.0008 L^2.66 (R2 = 0.89, N = 1290) and male specimens W = 0.0008 L^2.71 (R2 = 0.89, N = 1290) were resulted. The ratio between males to females (1.15: 1) showed a significant difference with 1:1 ratio. Fishing mortality, natural mortality and exploitation coefficient were calculated as 1.75, 0.5, 0.78 per year, respectively. The amount of snail fishing effort and catch indicates that Brice and Pozm stations had the highest and lowest catch rate as well as fishing effort (day- boat) at the time of snail harvest. In general, the fishing status of Babylon snails is about 678 tons with 4569 days of fishing effort - boat fishing per year and the average catch per unite effort (CPUE) of each boat is about 150 kg and the average catch per cage is about 0.59 Kg per cage. The average of Maximum Sustainable Yield (MSY), Maximum Constant Yield (MCY) and Total Allowable Catch (TAC) is estimated in the range of 170-260 tons. Fishing mortality, exploitation coefficient, peresent fishing mortality to maximum sustainable yield fishing mortality ratio (F/FMSY), peresent biomass to maximum sustainable yield biomass ratio (B/BMSY) indicate overfishing of this species is in Sistan and Baluchestan province.
Keywords: Maximum sustainable Yield, Exploitation coefficient, Fishing effort