Research
Sharks and Rays Fisheries of the Bay of Bengal at the Landing Centers of Chittagong and Coxas Bazar, Bangladesh
The study was conducted on the species composition and percentage contribution of sharks and rays from two landing centers (Fishery ghat, Chittagong and BFDC fish harbour, Cox’s Bazar) during 2011-2012 fiscal years. A total 10 species of sharks belonging to 3 families and 14 species of rays belonging to 8 families were recorded. Total landings of sharks and rays by weight were 382.67 MT of which 136.45 MT was sharks and 246.22 MT of rays. A total 479661number of sharks and rays were landed of which 449133 were sharks and 30528 were rays but contribution of sharks and rays were 35.66% and 64.34% respectively by weight. The highest landing was 70.94 MT in the month of October, 2011 and lowest landing was 6.05 MT in the month of January, 2012. The highest landing of shark species was Scoliodon laticaudus 84.52 MT (22.09%) and lowest was Carcharhinus sorrah 0.01MT and the maximum and minimum landing of rays species were Himantura uarnak 164.42MT (42.97%) and Aetobatus narinari 0.03% MT respectively.
Landing Trends, Species Composition and Percentage Composition of Sharks and Rays in Chittagong and Coxas Bazar, Bangladesh
The study was conducted from April, 2006 to June, 2010 on landing trends, species composition and percent contribution of sharks and rays by weight using the catch records of Marine Fisheries Survey Management Unit, Chittagong from two landing centers Fishery ghat, Chittagong and BFDC ghat, Cox’s Bazar. This study identified 27 species in total representing 11 species of shark (04 families) and 16 species of ray (09 families). The highest landing volume (134 MT) and contribution (76%) to total catch for the whole sampling period was found from Scoliodon laticaudus followed by Rhizoprionodon acutus (108 MT or 55%), Carcharhinus melanopterus (75 MT or 38%), Sphyrna zygaena (49 MT or 26%), Chiloscyllium indicum (38 MT or 20%), Eusphyra blochii (22 MT or 11%) Galeocerdo cuvier (21 MT or 10%) and other (03 MT or 2%). Species which occurred least were placed in the ‘other’ category comprising Carcharhinus amblyrhynchos, Stegostoma fasciatum, Carcharhinus leucas and C. falcifomis. Among rays, the landing volume and resultant percent contribution to overall catch found highest from Himantura uarnak (219 MT, 120%), followed by Himantura walga (158 MT or 60%), Himantura bleekeri (68 MT or 34%), Rhinobatos granulatus (29 MT or 18%), Gymnura micrura (12 MT or 7%) Mobula diabolus (11 MT or 5%), Rhynchobatus djiddensis (10 MT or 5%), Aetomylaeus nichofii (9 MT or 4%), Rhinoptera javanica (8 MT or 4%) and Narcine timlei (7 MT or 4%) and other species with least occurrence (5 MT or 4%). Species in other category consisted of Gymnura poecilura, Rhina ancylostoma, Himatura gerrardi, Anoxypristis cuspidata, Himantura undulata and Taeniura. Sps. Landing of different species were found to vary from month to month and year to year throughout the sampling period. To make absolute comment regarding these trends of occurrence, base line biological information together with long term catch record for size distribution was needed which could not be work out from the present data set. Ho
