Survey on the status of Narrow-Barred Spanish Mackerel (Scomberomorus commerson) And Indo-Pacific King Mackerel (Scomberomorus guttatus) stock using length-frequency distributions in Sistan and Baluchistan province

The study of some biological aspects of Narrow-barred Spanish mackerel (Scomberomorus commerson) was done in 1380-1381 in Oman Sea (Sistan and Baluchistan province). Analysis of catch/effort statistics of Shilat Statistical system was also made for the species and Indo-pacific King mackerel (Scomberomorus guttatus) from the year 1376 to 1381 Analysis of Gonadosomatic index of the former species, indicated a protracted spawning period of March to August, with a peak in April-May. The results of hepatosomatic index indicated the highest value before the maximum of G.S.k value in May and then decreased afterwards. The sex ratio was about 1:1 during the study the basis of LM50% (94 cm) and releasing fish below 96 cm fork length, the standard mesh size of the Narrow-barred Spanish mackerel was obtained as 171 mtn (stretched mesh size). Small pelagic fish (Clupeidae) accounted for a major part of the stomach contents (47%). There is available information on _ the length—frequency -distribution-ofthe-specieSby month and gear. The proportion of the species catch has also been analyzed by fishing gear (small-mesh and larger-mesh nets). The parameters of population dynamics of the species was obtained by using length frequency data and compared to the previous studies in Indian Ocean Estimated exploitation rate of the species (E=0.81) indicated a high level result. The total landings of Narrow- barred Spanish mackerel have been increased up tol .9 times from the year 1376 to 1381 spite of decreasing the total efforts (panel.day) from 1376 to 1381 -The CPUE values of (Kg/panel.day) the species have been increased. The CPUE values of Indo-pacific king mackerel have been decreased from 1377 to 1381 as well as of decreasing the total landings (69%). Iranian Fisheries Science Research Institute Published