Species composition and genetic stock structure of elasmobranchs in the Indo - West Pacific Ocean
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Date
2022
Authors
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Journal ISSN
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Publisher
Sokoine University of Agriculture
Abstract
Although Tanzania has prohibited the capture and sale of endangered elasmobranchs,
there is a chance that the fish are traded in processed form because fish products in the
country are traded in such forms. Therefore, this study used DNA barcoding to assess the
composition and conservation status of elasmobranchs landed and traded in Tanzanian
fish markets. Fin tissues of 102 elasmobranchs were collected from fish markets in Tanga,
Dar es Salaam, Nungwi, Kilwa and Mtwara between 2020 and 2022. Fragments of the
Cytochrome Oxidase Subunit 1 gene were amplified and sequenced from the DNA
extracts of each sample. The results showed that 23 different species of elasmobranch are
landed and traded in Tanzanian fish markets. However, 50% of the traded species are
listed as either endangered or critically endangered on the IUCN Red List, and 49% of
them are CITES protected. This indicates that although Tanzania prohibited fishing and
trade in endangered elasmobranchs; many of these species are still fished and sold in local
markets. This shows that the ban on endangered elasmobranchs is not being effectively
enforced and that fishing activities continue to endanger the protected species. Therefore,
the DNA based approach is suggested to be used by authorities to identify threatened and
protected species of elasmobranch. Measures should be taken to strengthen enforcement
of the fisheries regulations 13 (11) and 67 (2) of 2009 at landing sites and fish markets in
the country. Similarly, efforts should be taken to raise fishers’ awareness of the protected
elasmobranchs.
Description
Dissertation
Keywords
DNA barcoding,, Tanzania, Illegal trade, Sharks and rays, DNA barcoding, Endangered elasmobranch