Species composition of the largest shark fin retail-market in mainland China

Species composition of the largest shark fin retail-market in mainland China

Diego Cardeñosa, Andrew T. Fields, Elizabeth A. Babcock, Stanley K. H. Shea, Kevin A. Feldheim & Demian D. Chapman 

Scientific Reports Volume 10, Article number: 12914 (2020)
31 July 2020

Abstract

Species-specific monitoring through large shark fin market surveys has been a valuable data source to estimate global catches and international shark fin trade dynamics. Hong Kong and Guangzhou, mainland China, are the largest shark fin markets and consumption centers in the world. We used molecular identification protocols on randomly collected processed fin trimmings (n = 2000) and non-parametric species estimators to investigate the species composition of the Guangzhou retail market and compare the species diversity between the Guangzhou and Hong Kong shark fin retail markets.

Species diversity was similar between both trade hubs with a small subset of species dominating the composition. The blue shark (Prionace glauca) was the most common species overall followed by the CITES-listed silky shark (Carcharhinus falciformis), scalloped hammerhead shark (Sphyrna lewini), smooth hammerhead shark (S. zygaena) and shortfin mako shark (Isurus oxyrinchus). Our results support previous indications of high connectivity between the shark fin markets of Hong Kong and mainland China and suggest that systematic studies of other fin trade hubs within Mainland China and stronger law-enforcement protocols and capacity building are needed.

Introduction

Many shark populations have declined in the last four decades, mainly due to overexploitation to supply the demand for their fins in Asia and meat in many other countries1,2,3,4. Mainland China was historically the world’s second largest importer of shark fins and foremost consumer of shark fin soup, yet very little is known about the species composition of shark fins in this trade hub2. Most global shark catch and trade data are aggregated, unreported, or misidentified at the species level, hampering species-specific management and product traceability throughout supply chains5,6. Species-specific monitoring of the shark trade has become a priority for most countries, in part because of international treaty obligations under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) where several shark species traded in large volumes have been listed on Appendix II7,8.

One key source of species-specific information on the international trade of shark fins has been the systematic studies of the dried fin market of Hong Kong Special Administrative Region of the People’s Republic of China (hereafter referred to as Hong Kong)1,7,9. Hong Kong is arguably the world’s largest and most consistent importer and re-exporter of shark fins, a small-scale processor (i.e., removing extraneous tissue and preparing fins for the retail market), and a major consumer of shark fin soup2,10. However, despite its consistency it is unwise to assume that the species composition of Hong Kong is representative of all of the international fin trade because there are other hubs in Asia, each with their own internal dynamics, supply chains, and customer preferences2.

The fin trade in Mainland China, for example, differs from Hong Kong in at least two major respects: it is also a shark fin producer through its distant water fishing fleet2 and Guangdong province in southern China hosts a substantial fin processing industry, where fins landed or imported into China (including many from Hong Kong) are dried, soaked in water, bleached and trimmed of extraneous tissue (e.g., muscle, skin, cartilage) to isolate the ceratotrichia that are the primary soup ingredient2,11.

Shark fins in the city of Guangzhou are obtained from processing plants in Guangdong and then sold to local costumers, and restaurants and wholesalers in Beijing, Shanghai and other cities11. Interview surveys with local traders in Guangzhou suggested that shark fins in this market include tiger sharks (Galeocerdo cuvier), silky sharks (Carcharhinus falciformis), blue sharks (Prionace glauca) and oceanic whitetip sharks (C. longimanus)11, although no species-specific survey has ever been conducted in this market, hampering a direct comparison with other shark fin markets.

The objectives of this study were to (i) investigate for the first time the species composition of the Guangzhou dried fin market and (ii) compare the species composition of the Guangzhou and neighboring Hong Kong retail markets in terms of species diversity and most commonly traded species. From 2014 onwards, fin market surveys in Hong Kong have used fin-trimmings, an inexpensively sold byproduct of fin processing that is composed of pieces of fin with cartilage that have been cut away from the ceratotrichia, as an affordable market proxy7,9. This same proxy was used in Guangzhou.


Conclusions

The proportion of species or species groups in IUCN threatened categories was similar for the parallel sampling efforts: 37.9% (Hong Kong) and 41.8% (Guangzhou). The present study thus extends the previous work in Hong Kong7,9 by revealing that Guangzhou is trading fins from a similar diversity of sharks, rays, and chimaeras, and more than a third of the traded species exhibit high extinction risk. We also found that CITES-listed species were prevalent in Guangzhou, although potential latency of products imported prior to implementation in late 2014 (hammerheads, oceanic whitetips) or 2016 (silky, threshers) makes it difficult to pinpoint how much of this represents illicit trade (i.e., specimens imported into China without appropriate CITES documentation). It is also unclear how much of this originates from whole fins initially imported (and perhaps reported to CITES) into Hong Kong and then reexported and processed near Guangzhou.

Guangzhou exhibits a strong skew in species composition, being dominated by a small subset of the total species diversity (e.g., only 13 species represented by > 20 fin trimmings). Most of these were oceanic sharks that represented the largest proportions overall (71.6%)7,9. Skewed species composition was also characteristic of Hong Kong, with skews to many of the same species that dominated Guangzhou7,9.

The only substantial difference in composition between the two sampling locations was that the shortfin mako was almost twice as common in the Guangzhou than in Hong Kong trimmings (i.e., 4.16% vs. 2.37%) and had a higher incidence (i.e., higher proportion of bags with identified shortfin mako shark trimmings). As a result, it modeled as the fifth most common species in Guangzhou where it was ninth behind several coastal species (e.g., spinner [C. brevipinna], bull [C. leucas], Java [C. amboinensis]) that were more common in Hong Kong7. This could potentially mean there are different and direct supply chains for this species into Mainland China, possibly their own high seas longline fleet, which may increase its presence in trimmings in Guangzhou relative to Hong Kong. This potential input into China is an important issue since the shortfin mako was recently listed on CITES Appendix II. The distant water fleet is now required to report landings of this species to CITES under “Introduction from the Sea” rules8.

The similarity between the species composition of fin trimmings in the shark fin markets of Hong Kong and Guangzhou extends previous studies that suggest these two markets are connected10 and is not surprising considering the proximity (129 km) and overland connections (road, rail) between these cities. Hong Kong has historically been the trading port of entry to mainland China, where fins arrive and are sent to the Guangdong Province for processing and processed fins are sent back to Hong Kong and other major cities in mainland China for consumption10.

We suggest that some of the similarity we observed is driven by a similar supply chain for the trimmings: fins from Mainland China and Hong Kong are largely processed in Guangdong and resulting trimmings are then returned to these hubs for sale in their local retail markets. Although the border separating Hong Kong and Guangzhou is not international, CITES permits for listed species are required for transit (Hong Kong Agriculture Fisheries and Conservation Department [AFCD], pers comm). Given the prevalence of CITES listed species in both markets during our survey we suggest some surveillance investments for CITES listed shark products at the Hong Kong-China border is likely warranted20,21.

Despite the contemporary similarity found between the species composition of a fin market proxy in Hong Kong and Guangzhou, we suggest that capacity building and systematic studies of other fin trade hubs within Mainland China, Viet Nam, Singapore, Japan, Thailand, Taiwan, and Malaysia, are needed. Shark fin imports have declined sharply in both Hong Kong and especially China since 20112 for a variety of potential reasons (e.g., changes in reporting and sourcing, new policies prohibiting extravagant spending by the governmental sector, reduced public demand), while imports have increased in some of these other hubs2. Since these hubs are less culturally and geographically connected to Hong Kong and Guangzhou, they are likely to have different inputs and preferences that could affect species composition.

Indeed, some appear to focus on small, low value fins as opposed to the large valuable ones mainly traded in Hong Kong and China2. We therefore recommend investments in approaches to monitor the species composition of these hubs as well, in order to gain a clearer understanding of the species-specific dynamics of the international shark fin trade. Nonetheless, continued monitoring of the Hong Kong-Guangzhou hubs is necessary given the relatively high proportion of species threatened with extinction and/or listed under Appendix II of CITES in our surveys.

https://www.nature.com/articles/s41598-020-69555-1

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