Molecular approaches to reduce the illegal trade of shark and ray products in Indonesia

Prasetyo, AP

Abstract

Trade restrictions have been established to counteract the rapid global decline of sharks and rays (hereafter called elasmobranchs), such as controlled species under CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora). This has resulted from high fishing pressure, by-catch and market demand for certain products (e.g. fins). Tackling the illegal trade of endangered species poses enormous challenges for authorities, including taxonomic ambiguity, product variety, logistical issues for inspections and trade flow complexity. Based on extensive trade statistics, we found there was a substantial mismatch between exports of elasmobranch fin and meat products and the corresponding figures reported by importing countries ($43.6 M and $20.9 M for fins and meat, respectively) from the top shark landing country; Indonesia. That may signal illegal trading activities. When key visual identification for shark products disappears, genetics tools may help to improve trade monitoring. Over 579 tissue samples were collected in many locations (export hubs, processing plants, collectors, authority offices and landing sites) across Java Island, Indonesia, which have diverse processing conditions. Portable genetic techniques are urgently required to improve traceability, and we tested a recently developed universal assay (known as FastFish-ID) based on real-time PCR. By combining visual and deep learning assignment methods, we were able to successfully validate the method on 25 out of 28 species, 20 of which were CITES-listed. However, the illicit trade may be concealed from inspection, and that is a challenge for individual tissue-based genetic approaches. The ‘shark-dust’ metabarcoding approach offers an innovative application of metabarcoding to reveal the diversity of sharks being traded only based on the processing residues. This stupendous technique revealed 27 more taxa than individual tissue-based techniques and found that over 80% of the reads belonged to CITES-listed species. We argue that these approaches are likely to become a powerful, cost-effective and applicable monitoring tool wherever marine wildlife is traded globally.

Keywords: trade monitoring, conservation, CITES, sharks, rays, lab-on-the-field, portable tool, DNA metabarcoding, environmental DNA, Indonesia

Citation

Prasetyo, A. (2022). Molecular approaches to reduce the illegal trade of shark and ray products in Indonesia. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Apr 12, 2023
• Publicly Available Date: Apr 12, 2023
• Additional Information: Additional Information : Relevant works related to this thesis can be found here https://linktr.ee/dhika_fishery.; Funders : Illegal Wildlife Trade (IWT) Challenge Fund; Projects : Building capacity to reduce illegal trade of shark products in Indonesia; Grant Number: IWT057
• Award Date: Aug 1, 2022