Abstract
Trade involving elasmobranch products in Bangladesh is a four-decade-long practice in large scale and there is little understanding of its impact on species composition, population, and subsequent conservation. Capacity for monitoring and identification is lacking in landing and shark processing centres. A rapid survey and collection of tissue samples were performed in three landings and nine shark processing centres between 2016 and 2017 in the south-eastern coastal region of Bangladesh. Sequencing for a 707-bp fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene was used to assess the taxonomic status and species composition from 71 elasmobranch tissue samples collected from the shark processing centre only. Good quality COI sequences were obtained for 34 specimens representing 21 species—the majority of which are threatened with extinction. A total of ten species of sharks (Carcharhinus brevipinna, C. amboinensis, C. leucas, C. sorrah, C. amblyrhynchoides, Chiloscyllium burmensis, Galeocerdo cuvier, Rhincodon typus, Scoliodon laticaudus, and Sphyrna lewini), eleven species of rays (Aetomylaeus maculatus, Gymnura poecilura, Mobula mobular, M. kuhlii, Neotrygon indica, Pateobatis uarnacoides, Rhinoptera javanica, and R. jayakari), including three species of guitarfish (Glaucostegus granulatus, G. obtusus, and G. typus), were identified. Four species (14.7% of samples) were found to be listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) in Appendix II. Sixteen species (59% of the specimens) were threatened with extinction according to IUCN Red List, whereas 41% were data deficient or not assessed. The results have important implications for the management of regional fisheries and the conservation of elasmobranchs as they 1) represent a preliminary understanding of elasmobranch diversity in trade; 2) depict a lack of awareness and monitoring; and 3) demonstrate a need for urgent monitoring and regulation of elasmobranch trade in Bangladesh.
Highlights
Estimates suggest that a quarter of shark and ray species are threatened with extinction primarily driven by unsustainable fisheries, unprecedented bycatch, habitat destruction and illegal unreported and unregulated (IUU) practices globally [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]
c oxidase subunit I gene (COI) barcode sequences were obtained for 34 samples with sequence lengths varying between 281 and 650 bp (Table 1)
Unregulated elasmobranch fishery in Bangladesh reveals trade on protected species surveys in the landing sites to decipher catch trends and trade with an emphasis on CITESlisted, Data Deficient, and species threatened with extinction
Summary
Estimates suggest that a quarter of shark and ray species are threatened with extinction primarily driven by unsustainable fisheries, unprecedented bycatch, habitat destruction and illegal unreported and unregulated (IUU) practices globally [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]. Along with an array of other Asian countries (Sri Lanka, India, Bangladesh, Indonesia, Malaysia, Maldives, Myanmar, Sri Lanka, and Thailand) are either importing, exporting, or both [13,14,15,16,17,18,19], making Asia and adjacent areas the trade hub for elasmobranchs. These fisheries are largely unregulated and data on species composition is extremely limited [20]. DNA barcoding has been used as an efficient method to monitor traded products in several studies addressing this issue [3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
