Estimation of Biomass and density of green tiger prawn (Penaeus semisulcatus, De Haan, 1844) in Bushehr province, Persian Gulf

Biomass and density of green tiger prawn were estimated in Bushehr waters during July - August in 2004, 2005 and 2006. Study area was located from Motaf (27 30 N and 51 50 E) to Daylam waters (30 00 N and 50 00 E) in the northern part of the Iranian waters of the Persian Gulf with about 2000 nm limit. 45 stations in 15 transects were selected in the waters less than 10 m, 10-20 m and 20-30 m deep. Sampling was done by bottom trawl net. The maximum catch per unit effort (CPUE) of green tiger prawn was obtained in south area. From middle to end of shrimp fishery season (August) CPUE increased in the northern area. Based on our estimations, the initial total shrimp biomass in the south area was 674, 1024 and 873 tons in 2004, 2005 and 2006, the percentage biomass being 77, 75 and 86, respectively.Investigation of the shrimp concentration in the Bushehr waters showed that the green tiger prawns entered the fishing grounds from the southeastern parts of Bushehr waters, and Motaf, Nakhilu, Rase khan and Rod mond could be considered the initial appearance zones. Dense schools of green tiger prawns were observed above 10 meter depth in late June and early July and at 20-30meter depth in late July.