Biomass estimation of demersal resources in the Persian Gulf and Oman Sea by Swept area method

Regarding to monitor of demersal resources in the Persian Gulf and Oman Sea, and also biomass and CPUA estimation of them, eleven research cruises were carried out by using R/V Ferdows-1 equipped with bottom trawl, covering the area from 49º 00´ E in the west (borderline with Kuwait) to 61º 25´ E in the east (borderline with Pakistan) from 2009 to 2011. The study area was stratified into 17 strata (A to Q) of which 10 strata (A to J) were in the Persian Gulf and 7 strata (K to Q) were in the Oman Sea, covering the depths of 10-50 m in the Persian Gulf and 10-100 m in the Oman Sea. A total of 316 stations were randomly selected and the biomass and CPUA were estimated by swept area method. In 2009, due to the bloom of jellyfish, there was some problem for sampling and therefore made some bias in our estimation. Therefore, the biomass of jellyfish was excluded from all calculations. The comparison between two regions indicated that the percentage of density of demersal fishes in the Persian Gulf during years 2009, 2010 and 2011 were 1.5, 3.7 and 1.7 times more than the Oman Sea and totally 60-80% of total biomass was found for the Persian Gulf. Also a comparison among 17 strata the highest biomass was found for K region (Sirik to Jask) in the Oman Sea in 2009 & 2011; and C & D regions (Genaveh to Dayyer) in 2010 in the Persian Gulf. The same comparison was done for CPUA of commercial, non-commercial and total in both water bodies and it was found that in years 2009 and 2011 the regions of L (Jask to Meidani) and K (Sirik to Jask) in the Oman ; and 2010 the G region (Mogham to Farour) in the Persian Gulf had the highest value of this parameter. It can be concluded that the north-west of the Oman Sea has the best condition of biomass and CPUA of commercial and non-commercial demersal fishes; and on the contrary the low values were estimated for A region (north-west of the Persian Gulf) and P region (Konarak to Ramin) in the Oman Sea. With review the mean CPUA in defferent depth layers for years 2009, 2010 and 2011, it was concluded that with increasing the depth, the mean CPUA is decreased and the lowest CPUA belongs to depths of 50-100 m. The comparison between commercial and non-commercial groups in both ecosystems, it concluded that the density of commercial species were higher than non-commercial ones; and for years 2009, 2010 and 2011 the commercial species consist of 52.2, 57.1 and 59.7 % of total biomass. In all years the Persian Gulf indicated higher values than the Oman Sea. The most abundant fishes were Rays, Catfishes, Grunts, Japanese threadfin bream, Carangids, Hair tail, Barracuda and Lizardfish for both Persian Gulf and Oman Sea.

Bibliographic Details

Main Authors:	Valinasab, Tooraj, Daryanabard, G.R., Taghavi, S.A., Kashi, M.T., Ansari, H., Neekpay, M., Hossaini, S.A., Niameymandi, N., Shabani, M.J., Moradi, Gh., Talebzadeh, S.A., Darvishi, M., Bayat, Y., Esmaieli, A., Mayahi, Y., Khodadadi, R., Kamali, E., Behzadi, S., Salarpori, A., Radkhah, K.
Format:	Report biblioteca
Language:	Persian
Published:	Iranian Fisheries Science Research Institute 2013
Subjects:	Commercial fishes, Non-commercial fishes, Biomass, Catch per unit of area, CPUA, Sampling, Density, Species, Catfishes, Grunts, Japanese threadfin bream, Carangids, Hair tail, Barracuda, Lizardfish,
Online Access:	http://hdl.handle.net/1834/13298
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