Survey of Tuna fish stocks in coastal Sistan and Balouchestan

Abstract

The method is used to catching tuna fish in the coastal sistan and balouchestan is gillnet.The amount of tuna catch fish has changed in 75 and it has increased in comparison with 3years ago . Total catch of tuna fish have changed from 18150 ( t ) in 71 to 25932 (t) in 75 and always the most percentage of catch has related to yellow fin tuna. skipjak tuna with 7 .9 percentage and long tail tuna with 5.7 percentage in second and third grad of catch . most of the tuna fishes have cathed in the east landings.only Auxis thazard has cached inthe west landings. studing yellow fin tuna nourishing show which squied is the most abundant itemes in it s stomach the stomach compositions skipjack tuna has had variety and number less than yellow fin tuna so crab and fish are found in it s stomach. The length frequncy of yellowfin tuna compared with age class which presented by( Siva subra maniam., 1971) according to this Comparision more percentage of yellow fin tuna catch is below one years old and % 50 maturation for this species is in 3 age . Comparision the length frequency of longtail tuna and skipjack tuna with age class show which most of them are 4 age and biger than it . To revise mesh size gillnet and area of traditional catch for these species has emphasized.