Global Journal of Science Frontier Research: D Agriculture and Veterinary Volume 14 Issue 4 Version 1.0 Year 2014 Type : Double Blind Peer Reviewed International Research Journal Publisher: Global Journals Inc. (USA) Online ISSN: 2249-4626 & Print ISSN: 0975-5896 Landing Trends, Species Composition and Percentage Composition of Sharks and Rays in Chittagong and Cox’s Bazar, Bangladesh By Roy Bikram Jit, Md. Fokhrul Alam, Md.Gaziur Rhaman, Nripandra Kumar Singha & Aysha Akhtar University of Chittagong, Bangladesh Abstract- 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. Keywords: shark, ray, species composition, elasmobran-ches fishery, landing trend, catch data, abundance, percent contribution. GJSFR-D Classification : FOR Code: 079999, 070403 LandingTrendsSpeciesCompositionandPercentageCompositionofSharksandRaysinChittagongandCoxsBazarBangladesh Strictly as per the compliance and regulations of : © 2014 Roy Bikram Jit, Md. Fokhrul Alam, Md.Gaziur Rhaman, Nripandra Kumar Singha & Aysha Akhtar. This is a research/review paper, distributed under the terms of the Creative Commons Attribution-Noncommercial 3.0 Unported License http://creativecommons.org/licenses/by-nc/3.0/), permitting all non commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Landing Trends, Species Composition and Percentage Composition of Sharks and Rays in Chittagong and Cox’s Bazar, Bangladesh α σ ρ Ѡ ¥ Roy Bikram Jit , Md. Fokhrul Alam , Md.Gaziur Rhaman , Nripandra Kumar Singha & Aysha Akhtar Abstract- The study was conducted from April, 2006 to June, consists of continental shelf providing a rich resource of 2010 on landing trends, species composition and percent coastal fisheries. In Bangladesh economy, fisheries 2014 contribution of sharks and rays by weight using the catch sector plays a significant role through generating r records of Marine Fisheries Survey Management Unit, employment and providing major source of animal ea Chittagong from two landing centers Fishery ghat, Chittagong Y protein for the population. Shark fishery is largely and BFDC ghat, Cox’s Bazar. This study identified 27 species 17 in total representing 11 species of shark (04 families) and 16 artisanal, multi gear and multispecies fishery in species of ray (09 families). The highest landing volume (134 Bangladesh which occurs from the coasts to the edges MT) and contribution (76%) to total catch for the whole of the EEZ. Sharks and rays come mostly as by catch sampling period was found from Scoliodon laticaudus but in recent years, some shark targeted boats are followed by Rhizoprionodon acutus (108 MT or 55%), introduced. The contribution of sharks and rays is only V Carcharhinus melanopterus (75 MT or 38%), Sphyrna zygaena 1% of our total marine landings. There are a range of IV (49 MT or 26%), Chiloscyllium indicum (38 MT or 20%), gears to harvest sharks but caught by shark net Eusphyra blochii (22 MT or 11%) Galeocerdo cuvier (21 MT or ue ersion I s (modified gill net) and rays are mainly caught by hook s 10%) and other (03 MT or 2%). Species which occurred least and lines. Besides, rays are also harvested as incidental I were placed in the ‘other’ category comprising Carcharhinus X amblyrhynchos, Stegostoma fasciatum, Carcharhinus leucas catch by set bag net and trammel net. In addition, large XIV and C. falcifomis. Among rays, the landing volume and number of small size rays (juveniles or just born) and resultant percent contribution to overall catch found highest sharks caught by shrimp trawl net remains unreported. from Himantura uarnak (219 MT, 120%), followed by Traditionally, elasmobranches have never been Himantura walga (158 MT or 60%), Himantura bleekeri (68 MT highly prized fish product. Their economic value ranks or 34%), Rhinobatos granulatus (29 MT or 18%), Gymnura D low among marine commercial fisheries. For example, in micrura (12 MT or 7%) Mobula diabolus (11 MT or 5%), the Taiwanese gill net fisheries of the central Western () Rhynchobatus djiddensis (10 MT or 5%), Aetomylaeus nichofii Pacific, shark trunk prices attain only 20% and 60 % of (9 MT or 4%), Rhinoptera javanica (8 MT or 4%) and Narcine those of Tunas and Mackerels respectively (Millington, timlei (7 MT or 4%) and other species with least occurrence (5 MT or 4%). Species in other category consisted of Gymnura 1981). The only valued elasmobranches product is Research Volume poecilura, Rhina ancylostoma, Himatura gerrardi, Anoxypristis shark fin for oriental soup, a commodity which recently cuspidata, Himantura undulata and Taeniura. Sps. Landing of has attained a considerable increase in demand (Cook, different species were found to vary from month to month and 1990). In our country, shark fins and ray skin are usually Frontier year to year throughout the sampling period. To make processed for export market and the meat part is sold absolute comment regarding these trends of occurrence, base for local consumption mostly to the tribal community. line biological information together with long term catch record However, fins of small sized shark have no export value Science for size distribution was needed which could not be work out and therefore sold as raw meat or in dried condition. from the present data set. However, total landing of sharks of Recently, number of shark fishing boats, fishing and rays were found to be on slight decline. Keywords: shark, ray, species composition, elasmobran- days and export trade have been expanding rapidly which gives some cause of alarm. Moreover, catch of ches fishery, landing trend, catch data, abundance, Journal percent contribution. small size or juvenile sharks and rays has increased with the decrease of large size sharks reminding us that the stock may be undergoing overexploitation (Halder, I. Introduction Global 2010). In Bangladesh, landing of shark is not reported angladesh has a long coastline of 714 km and by species but by groups i.e. sharks and rays in yearly comprising an Exclusive Economic Zone (EEZ) of statistical report by the Department of Fisheries. Species B 164,000 sq. km. About 44 percent of our EEZ wise catch data is very important to know the catch composition, pattern of occurrence and to identify the Author α σ ρ Ѡ: Scientific Officer, Marine Fisheries Survey Management species under threat. Sharks are widely recognized as Unit, C.G.O, Agrabad, Chittagong, Bangladesh. e-mail: [email protected] being vulnerable to over fishing because they grow Author ¥: Assistant Professor, Institute of Marine Sciences and Fisheries slowly, are late to mature and produce relatively few University of Chittagong, Bangladesh. young. As a result, they are susceptible to over fishing ©2014 Global Journals Inc. (US) Landing Trends, Species Composition and Percentage Composition of Sharks and Rays in Chittagong and Cox’s Bazar, Bangladesh and slow to recover. Therefore, there has been a wooden boats of 5-7 meters long with engines of 45- realization that the stocks may be overfished and some 65/75 Hp. Each boat carries 17-18 fishermen and their management initiatives are required. In the present active fishing days last for 15-18 days depending on the study, effort has been made to determine the landing volume of the catch. The main gears include shark net trends, species composition and percent contribution of (gill net), set bag net (ESBN and MSBN), long lines and sharks and rays from April 2006 to June 2010 in the trammel net. Shark nets are large mesh gill net made of coasts of Chittagong and Cox’s Bazar. It is expected thread no.4 and having length, depth and mesh size of that the statistical interpretation would rightly focus on 1500-3000 m, 10-15 m and 450 mm respectively. Long the status of the resources and contribute towards any lines are mainly used for rays consist of a nylon national management plan for shark fishery of this monofilament mainline of 2 to 3 mm in diameter hung in country. a sagging curve between surface float. The branch lines with a length of 5-12 m descend from the main line, II. Materials and Methods 2014 each terminating in a single baited ‘J’ hook. The number a) Sampling Stations of hooks ranges from 800-6000 and hook size varies ear Y The study was under taken for about 04 years from No.6-11. Frozen squids (Loligo spp.) and cuttle fish starting from April 2006 up to June 2010 at two fish (Sepia spp.) and sardines (Sardinella spp.) are 18 landing centers i.e. BFDC ghat of Cox’s Bazar district commonly used as bait. Both long lines and gill nets are and Fishery ghat of Chittagong district situated at the shot in the evening and their retrieval begins after south-eastern part of the Bay of Bengal. These two midnight. landing centers were selected because the major b) Total Landing and Species Composition V landing of shark and ray is done here and the wholesale A total of 11 species of sharks (04 families) and IV and retail market is also located in these two places.