Time filter

Source Type

Braulik G.T.,University of St. Andrews | Ranjbar S.,Iran University of Science and Technology | Owfi F.,Iranian Fisheries Research Organisation | Aminrad T.,Offshore Fisheries Research Center | And 3 more authors.
Journal of Cetacean Research and Management | Year: 2010

Iran has 1, 700km of coastline that borders the Persian Gulf and the Arabian Sea in the northwest Indian Ocean. Apart from a handful of records, almost nothing is known about which marine mammal species occur in Iranian waters. This review was conducted to fill this information gap. A total of 127 marine mammal records of 14 species were compiled from Iranian coastal waters. Ninety-nine were from the Persian Gulf, 26 from the Gulf of Oman and 2 were of unknown location. Records of finless porpoise (Neophocaena phocaenoides) (25), Indo-Pacific humpback dolphin (Sousa chinensis) (24) and Indo-Pacific bottlenose dolphin (Tursiops aduncus) (22) were by far the most numerous, a probable reflection of their inshore distribution and local abundance. Other species recorded were long-beaked common dolphin (Delphinus capensis tropicalis), roughtoothed dolphin (Steno bredanensis), striped dolphin (Stenella coeruleoalba), spinner dolphin (Stenella longirostris), Risso's dolphin (Grampus griseus), false killer whale (Pseudorca crassidens), sperm whale (Physeter macrocephalus) and dugong (Dugong dugon). Records of 26 mysticetes were compiled, 10 of which were tentatively identified as Bryde's whales (Balaenoptera edeni), 1 possible fin whale (Balaenoptera physalus), 3 humpback whales (Megaptera novaeangliae) and the remainder were not identified to species. The largest threat to small cetaceans in Iran is likely to be incidental capture in fishing gear. Nine finless porpoises were recorded as bycatch and this and other coastal species may be declining due to unsustainable mortality rates. Some of the world's busiest shipping lanes pass through Iranian waters and ship strikes are likely to be the largest threat to mysticetes in the area.

Rabbaniha M.,Iranian Fisheries Research Organization | Mousavi Golsefid S.A.,Offshore Fisheries Research Center | Owfi F.,Iranian Fisheries Research Organization
Iranian Journal of Fisheries Sciences | Year: 2014

The study and research of abundance and diversity variation of fish larva (Ichthyoplankton stages) was done in Gowatr Bay during autumn 2006 - summer 2007. Five stations were selected for sampling, and Bongo-Net with 300μ mesh size was towing from bottom to surface. During of survey, totally 531 larvae belong to 11 families were collected and identified. The mean abundance estimated 12.17 larvae per 10 m2, which three fish larva family including: Gobiidae, Clupeidae and Engraulidae were dominant (86% of relative abundance). The result showed that there was significant differences between pre and postmonsoon fish larvae abundances (p<.05), and there were not significant differences between stations (p>.05). In pre-monsoon 4 families were identified of which Clupeidae introduced as indicator group, whereas in post-monsoon 10 families were identified and Gobiidae was indicator family, accompany with increase of diversity. PCA result was shown, temperature as the main factor affected on fish larvae assemblage was found with a significant decrease of 11.9 °C after monsoon phenomenon.

Kaymaram F.,Iranian Fisheries Research Organization | Hosseini S.A.,Offshore Fisheries Research Center | Darvishi M.,Gulf | Parafkandeh F.,Iranian Fisheries Research Organization
Turkish Journal of Fisheries and Aquatic Sciences | Year: 2014

This document analyses some population parameters of Yellowfin Tuna (Thunnus albacares) taken by drift gillnet operation from southern part of Iranian coast in the Oman Sea during 2007 to 2009. A total of 9,345 specimens of T. albacares were sampled in the size range of 37 cm to 172 cm fork length (FL). The mean length was estimated to be 86.12 cm. There was influence from seasonal variation on the length distribution of individuals, and it showed a tendency of gradual increase in the model length with the fishing season. The temporal change in length distribution is more likely to be an indication of feeding migration of medium-sized Yellowfin Tuna from the western Indian Ocean into the Oman Sea during January to June. The statistical analysis of length-weight relationship was achieved by sex. The electronic package "ELEFAN I" was chosen for describing the species' von Bertalanffy growth equation; parameters were L∞= 183.3 cm, K= 0.45 year-1, and t0= -0.184 year. Natural mortality (M) was 0.48 year-1, fishing mortality (F) 1.56 year-1, and total mortality (Z) 2.04 year-1. The exploitation ratio (E) was as high as 0.76. For sustainable exploitation of T.albacares, a decrease in fishing effort of the gillnet fishery would be alternatively an effective measure to decline the fishing pressure on the stock, and to prevent the probably overfishing events. © Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey.

Hosseini Aghuzbeni S.H.,Offshore Fisheries Research Center | Hajirezaee S.,Offshore Fisheries Research Center | Hajirezaee S.,University of Tehran | Matinfar A.,Iranian Fisheries Research Organization | And 2 more authors.
Journal of Applied Animal Research | Year: 2016

A polyculture system composed of western white shrimp, Litopenaeus vannamei and Mullet, Mugil cephalus, was established to create favourable biological condition and improve shrimp growth. Totally, nine earthen ponds of 600 m2 (three treatments with three replicates) were prepared in the Gwadar area (located in the coastal area of Oman Sea, southeast of Iran) for our experiment. The L. vannamei post-larvae (PLs) (average body weight: 0.007 ± 0.001 g) were stocked at a density of 20 PLs m−2 in each experimental pond. After 40 days of storage, mullets with size of 20–50 cm were stocked at densities of 0 (T1), 2 (T2) and 4 (T3) fish per 100 m2 of ponds, respectively. The growth parameters (including: specific growth rate, mean weight), food conversion ratio (FCR) and survival rate (SR) of shrimps were measured during the experiment. After 107 days of the experiment, the highest shrimp biomass was obtained in T3 (212 kg) and T1 yielded the lowest biomass (187 kg). The mean body weight of each shrimp was 18.4 and 16.23 g in T3 and T1, respectively (P < 0.05). The SR and FCR did not show significant differences between treatments (P > 0.05). In conclusion, the present experiment demonstrated that polyculture of western white shrimp with mullet improves growth and subsequently the production of western shrimp. © 2016 The Author(s). Published by Taylor & Francis

Hosseini S.A.,Offshore Fisheries Research Center | Lee C.-W.,Pukyong National University | Kim H.-S.,Pukyong National University | Lee J.,Pukyong National University | Lee G.-H.,South Korean National Fisheries Research and Development Institute
Fisheries Science | Year: 2011

This paper reports an improved version of the numerical method used in a previous study on the dynamic simulation of purse seine gear in three dimensions. The improvement is achieved by refining the mass-spring model to take into account both the drag coefficient as a function of the attack angle and Reynolds number as applied to the setting operation of the purse seine gear. The validity of the numerical simulation is assessed by comparing the measured and calculated values for the sinking depth of the net. The numerical simulation is used to examine the sinking performance of the different designs in which large meshed-panels and netting materials are used together in the main body section of the netting. The results indicate that, compared to the prototype net, nets bearing larger mesh panels require more sinking depth with much more pronounced operational depth at corresponding times of the fishing operation when heavier netting material is used. Moreover, in the new net designs, lower tensile forces are exerted on both ends of the pure wire during pursing. The new net constructions with regard to the operational depth represent alternatives that may reduce the potential problem of frequent failed setting of the tuna purse seine gear. © 2011 The Japanese Society of Fisheries Science.

Discover hidden collaborations