A multiplex PCR mini-barcode assay to identify processed shark products in the global trade

Shea²,

Zhang³

et al. 2019

Animal Conservation

Self Cite

The international fin trade is a major source of mortality for many threatened shark species but most of what it is known about this trade comes from assessments of large fins commanding high prices in trade hubs. There is growing international trade in ‘small, low‐value’ fins in Southeast Asia, which are used for inexpensive shark fin soup products. These fins could be derived from small species, juveniles of large species, or a combination of both. Resolving the species identification of these small fins has important conservation implications, because large sharks tend to be more vulnerable (VU) to overexploitation than small ones. Here we describe the first species‐specific assessment of the small, low‐value fins in the shark fin retail markets of Hong Kong. A total of 475 randomly collected samples were genetically identified using a portion of the cytochrome oxidase I, revealing at least 29 species. Around a third (34.5%) of the species found are in threatened International Union for the Conservation of Nature Red List categories, and 21.2% of the samples were from four species listed on Appendix II of the Convention on International Trade in Endangered Species (CITES). The size of the analyzed fins and the species composition found suggests that small fins come from a combination of small (62.9 %) and large (37.1%) species, with the majority of small fins coming from suspected juveniles of large species. We suggest the sources of most of these fins are likely to be multi‐species fisheries in shallow, coastal habitats used by large species and also occupied by small species. Our results represent the first step to better understand the trade in small shark fins on a species‐specific basis and highlight the need for market surveys and increased inspection of this fin category at border control check points for CITES‐listed species.

Section: Methodscontrasting

confidence: 95%

Small fins, large trade: a snapshot of the species composition of low‐value shark fins in the Hong Kong markets

Shea²,

Zhang³

et al. 2019

Animal Conservation

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“…With our rtPCR assay the frequency of false negative results could vary between individual runs according to the frequency of samples with low DNA quality (e.g., when tested on processed products) or the presence of PCR inhibitors. When the rtPCR multiplex was tested against processed shark fin samples, the bigeye thresher was the only CITES listed species included in the multiplex that failed to amplify, possibly due to the resulting large amplicon (i.e., >1000 bp) 15 . If false negatives are considered to be a major problem in law enforcement contexts we suggest that all test samples could be run twice: once with the rtPCR multiplex described and once with a protocol expected to amplify all shark products (e.g., a universal shark mini-barcode assay 34 or universal ITS2 primers 27 ).…”

Section: Discussionmentioning

confidence: 99%

“…Since Hong Kong authorities had not yet started to enforce the 2016 shark CITES listings at the time, the species-specific primers to detect the silky and thresher sharks were removed from the multiplex for these specific law-enforcement scenarios. For all of these cases a portion of the mitochondrial COI gene was later amplified and sequenced from unprocessed fins following the protocols by 31 , and from processed fins following the protocols by 15 to assess concordance with the multiplex results. Sequences were compared to BOLD (FISH-BOL) and BLAST (GenBank) databases to identify them to the lowest taxonomic category possible.…”

Section: Methodsmentioning

confidence: 99%

“…It is evident that enforcing CITES regulations is a major challenge, in part due to limited availability of rapid, reliable, and cost-effective tools to identify traded products 3 , especially for the species listed from 2013–2016 10 . Wildlife forensics tools, such as DNA barcoding 13 – 15 and PCR-based species-specific assays 16 – 18 , are the most reliable and widely applicable species identification approaches available to assess and detect illicit activities associated with wildlife trade 19 – 21 . However, the application of these tools to detect CITES listed species is difficult when inspections must be conducted in a short time frame (e.g.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Multiplex real-time PCR assay to detect illegal trade of CITES-listed shark species

Quinlan

Shea³

et al. 2018

Sci Rep

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100

The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) is a multilateral environmental agreement to ensure that the international trade of threatened species is either prohibited (Appendix I listed species) or being conducted legally, sustainably, and transparently (Appendix II listed species). Twelve threatened shark species exploited for their fins, meat, and other products have been listed under CITES Appendix II. Sharks are often traded in high volumes, some of their products are visually indistinguishable, and most importing/exporting nations have limited capacity to detect illicit trade and enforce the regulations. High volume shipments often must be screened after only a short period of detainment (e.g., a maximum of 24 hours), which together with costs and capacity issues have limited the use of DNA approaches to identify illicit trade. Here, we present a reliable, field-based, fast (<4 hours), and cost effective ($0.94 USD per sample) multiplex real-time PCR protocol capable of detecting nine of the twelve sharks listed under CITES in a single reaction. This approach facilitates detection of illicit trade, with positive results providing probable cause to detain shipments for more robust forensic analysis. We also provide evidence of its application in real law enforcement scenarios in Hong Kong. Adoption of this approach can help parties meet their CITES requirements, avoiding potential international trade sanctions in the future.

“…*Depicts countries that play as re-exporters, in this case, Singapore re-exported fins from CITES-listed species coming originally from Sri Lanka selected per bag. Subsequently, the genomic DNA of each trimming was extracted, PCR amplified, sequenced, and identified following previously used protocols that enable accurate species identification of all CITES listed sharks and most sharks, batoids, and chimaeras known to occur in trade (Cardeñosa et al, 2017;Fields, Abercrombie, Eng, Feldheim, & Chapman, 2015). A Poisson multinomial model (Baker, 1994;Shelton, Dick, Pearson, Ralston, & Mangel, 2012) was used to estimate species composition of the fin trimmings and a Bayesian framework with noninformative priors was used to estimate the parame-ters as described by Fields et al (2017) (Supplemental Material 1).…”

Section: Speciesmentioning

confidence: 99%

CITES‐listed sharks remain among the top species in the contemporary fin trade

Fields

Babcock

et al. 2018

CONSERVATION LETTERS

Self Cite

101

Trade-driven overexploitation threatens many sharks. Twelve of the world's most vulnerable shark species have been listed on the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) to regulate internationally traded products such as meat and dried fins. CITES records indicate that Hong Kong was the world's top legal importer of dried fins from listed sharks in 2015 (N = 8 species at that time), but traded a relatively small volume, with a few partners, in a small number of shipments (16). In contrast two CITES Appendix II listed hammerheads were consistently the fourth and fifth most common species (out of >80) in processed fin trimmings (N = 9,200) collected randomly from the Hong Kong retail dried fin market from February 2014 to December 2016 and were found in 100% of sampling events and in 66% of sampled retail vendors. This difference, and the fact that exporting nations previously known to land these species were not among those to report trade to CITES, suggest that listed species were often imported without CITES documentation in 2015. There are a number of incentives for trade hubs to meet their obligations to this treaty, which they could achieve by scaling up monitoring capacity and increasing inspection efficiency. K E Y W O R D SCarcharhinus falciformis, CITES enforcement, shark conservation, shark fin trade, sphyrna lewini, sphyrna zygaena, wildlife forensics