Stock assessment of Black pomfret (Parastromateus niger) in the Sea of Oman (Coastal waters of Sistan and Baluchistan Province)
Subject Areas : New Technologies in Aquaculture Development
Keywords: Keywords: Stock assessment, Parastromateus niger, Sea of Oman, Demersal resources,
Abstract :
Abstract Parastromateus niger is one of the most important species which has been studied in the project of “stock assessment of demersal resources by swept-area method in the Oman sea (1999-2000). 4 research cruises were conducted by R/V Ferdows-1. The area chosen for the study was from Meidani (58° 55' E) to Gwatre Bay (61° 30' E) having depths of 10 to 100m.The studied area of 1164 n.sq.mil. was divided into 5 sub regions (A,B,C,D&E) each covering 30Minutes width. Each region was divided into 4-depth stratum: 10-20, 20-30, 30-50, and 50-100 meters .In each cruise, sampling was carried out for more than 90 stations using a bottom trawler. The seasonal and annual biomass for each region and stratum was estimated. The average annual biomass for the whole area was calculated as 616.37 tons and for each stratum of 10-20, 20-30, 30-50, and 50-100 m the estimation was 276.62, 105, 66.5, and 168.27 tons respectively. The maximum biomass was located in the depth of 10-20 m while the minimum was found in the depth of 30-50 meters. The annual average biomass for different regions of A, B, C, D and E was calculated as 75.27, 48.91, 224.03, 97.64, and 170.53 tons respectively. The fork length and total weight of 1258 specimens of p. niger were measured; the fork length ranged from 14.5 to 58.5 centimeters. Comparison of distribution patterns indicated that the p. niger inhabits mainly in front of estuary of Galak, Gordim and the head of Pozm. The seasonal parabolic equations of length and weight relationship were studied. In this regard, there was no significant difference among seasonal b-value. According to the calculated CPUA, the result indicated that in each season at least in one sampling station it was higher than the minimum base of concentrated level. The result showed that there is a schooling stock of this species in the region.
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