Stock assessment of sharks in the northern part (Iranian waters) of the Persian Gulf
Published online on 30. October 2014
Stock assessment of sharks in the northern part (Iranian waters) of the Persian Gulf
Nassir Niamaimandi, Toraj Valinassab, Gholam-Abbas Zarshenas
ABSTRACT:
This study was analyzed the annual catch and trawl survey data of sharks in the northern part of the Persian Gulf (26˚30΄ to 30˚00΄N and 49˚00΄ to 56˚00΄E) from 2004 to 2009. Trawl survey was conducted by research vessel Ferdous, equipped with bottom trawl nets in meshes 400mm and 80mm at body and cod-end respectively. Ten stratums were selected in the study area and 199 stations were randomly trawled. The density (CPUA) of shark resources was estimated based on swept area method. Annual total catch was obtained from Iranian fisheries organization (Shilat). The results of catch per unit area showed 250.7 kg/nm2 in 2004 to 49.7 kg/nm2 in 2009. There was a high degree of variability of CPUA among different areas and the maximum was estimated 1870.8 kg/nm2 in Nayband and Mogham. In catch composition data, sharks have a decreasing trend from 4.2% in 2004 to 2.9% in 2009 that shows a decline with an annual average 1.3% during 2004-2009 . This results suggesting that the shark resources are overexploited and the current effort is far higher than the effort required harvesting optimum yields.
Agriculture, Forestry and Fisheries. Vol. 3, No. 5, 2014, pp. 397-400.
doi: 10.11648/j.aff.20140305.21