E Biomass, distribution and length frequency of Saurida tumbil, Psettodes erumei and Grammoplites suppositus in summer and fall in the Systan and Balochestan coasts
Subject Areas : New Technologies in Aquaculture Development
Keywords: Oman Sea, Keyword: Monitoring of stock, Swept area method, Demersal fish,
Abstract :
Abstract[1] In order to study biomass and length frequency of 3 main species of Saurida tumbil, Psettodes erumei and Grammoplites suppositus, a research cruise was carried out in the Persian Golf, Systan and Balochestan waters using swept area method in 2000. The studied area was from Meidani (58˚ 55′ E) to Gwatre Bay (61˚30′ E) having depths of 10 to 100m. The studied area of 1164 n.m.sqr., was divided into 5 subregions (A, B, C, D and E) each covering 30 minutes width, each region was divided into 4 depth stratum: 10-20, 20-30, 30-50 and 50-100 m. In each cruise, sampling was carried out for more than 65 stations using a bottom trawler by R/V Ferdows. And then the following measurements such as the sampling of demersal species were carried out. The calculated annual biomass for the whole area was 41830.3 tons in 2000, and for each stratum of 10-20, 20-30, 30-50 and 50-100 m, indicating 22393.5, 5492.9, 1398.1 and 12545.7 tons respectively. It is clear that the maximum biomass lies at the depth of 10-20 m. The minimum was found at depth of 30-50 m. After the samples were identified, weighted and also some biological measurements were done. All data were analyzed by Excel, and were presented as figures and total biomass was estimated seperately in depth and area. The total biomass of Saurida tumbil, Psettodes erumei and Grammoplites suppositus, were estimated about 847.3, 162.4 and 279.9 tons, respectively. On the other hand the most length frequency of this species was found in length of 32-35 cm, 35-40 cm and 14-16 cm, respectively. *Corresponding authors; khanihm@yahoo.com
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