In the vibrant streets of Southeast Asia’s culinary landscape, amidst the bustling seafood markets where the aroma of exotic delicacies fills the air, an undercover investigation into the shark fin trading world here has unveiled shocking revelations.
Long hailed as a delicacy, shark fins have woven themselves into the cultural fabric of celebratory feasts and health tonics in many Asian regions, like Singapore. A sovereign city-state and island country located in Southeast Asia, it is situated at the southern tip of the Malay Peninsula, just north of the equator. Singapore plays a pivotal role in the intricate network of the shark fin trade. Here, the fins are frequently exported in dried forms and marketed using generic terms such as “shark fin” or “dried seafood,” rather than specifying the species of origin. This lack of specificity in labeling creates challenges for enforcing and monitoring the trade, as it can be ambiguous or intentionally vague. And that’s a huge problem, as two-thirds of the sharks involved in the global fin trade are at risk of extinction or come from populations that are in decline. Despite growing awareness of the need for shark conservation, the consumption of shark fin products remains rampant in Asia, contributing to a staggering USD 1 billion industry. The slow growth rates, late sexual maturity, and low reproductive output of sharks make them uniquely vulnerable to overfishing, disrupting entire marine ecosystems and triggering trophic cascades.
Led by YALE-NUS College scientist Kai-Lin Selena Shen, an international team collected 505 shark fin samples from 25 different local seafood and Traditional Chinese Medicine shops across Singapore. “Each species has a unique DNA sequence. Using this sequence we then compare it against known species IDs and their associated DNA sequence – these are available in public databases such as BOLD or GenBank,” comments co-author Benjamin John Wainwright. Employing cutting-edge DNA barcoding techniques, what they discovered was both astonishing and alarming — a staggering 27 different shark species, with three classified as Critically Endangered, four as Endangered, and ten as Vulnerable by the International Union for Conservation of Nature. The top five frequently encountered species in this investigation were the milk shark (Rhizoprionodon acutus; the most prevalent), the silky shark (Carcharhinus falciformis), school shark (Galeorhinus galeus), scalloped hammerhead (Sphyrna lewini) and the smooth hammerhead (Sphyrna zygaena).
Do consumers know they’re buying animals on the brink of extinction? It’s hard to know. But the scientists aren’t too surprised: “Unfortunately, this is not particularly surprising and is pattern seen all over the world.”
“The entire seafood supply chain is rife with opportunities for mislabelling and product substitution – more accountability throughout global supply chains would help, but, much of this fishing takes place far out at sea, or in counties were resources are limited so it is very easy to mislabel and any rules/regulations are easily flouted,” explains Wainwright. As a signatory to CITES, Singapore is obligated to prevent and monitor the trade of regulated species that pass through its borders. However, this task is challenging. Once a shark’s fin is removed and processed, identifying its species through visual methods alone becomes nearly impossible. This is the core issue: fins are imported under generic terms like “dried seafood,” without specifying the species. Customs officers would need to visually inspect each fin and potentially resort to genetic techniques for identification, which is time-consuming and may not always be feasible. “How can you create policy and regulations designed to protect sharks if you have no idea of the species that are involved in the trade? In one box/bag/shipment you could have hundreds of species of sharks that have been aggregated from markets all over the world – it is a really big challenge to make sure products are labelled correctly.”
This lack of accurate labeling not only hampers monitoring efforts but also poses a grave risk to consumers, potentially exposing them to unsafe concentrations of toxic metals. Sharks accumulate toxins at different rates, with pelagic species expected to have elevated levels of mercury. The indiscriminate consumption of shark fins poses health risks to consumers, with reports of toxic metal concentrations above established safe limits. “Work we published last year shows significant differences in toxic metal concentrations between species and whether or not that species is found in pelagic or coastal environments. Given this, accurate labelling/better supply chain accountability could help prevent the sale of species that are known to contain toxic metals above safe human consumption limits,” Wainright says.
With traditional methods of species identification proving inadequate, DNA barcoding emerges as a beacon of hope: “We are hoping to use advances in DNA sequencing technology and capacity to determine where a shark fin came from/was caught, this work will use techniques very similar to those used in human ancestry testing (e.g., 23andME, ancestry.com),” concludes Wainright. “We work locally with other shark researchers in Singapore/Southeast Asia and have ongoing/upcoming projects that will examine the toxic metal concentrations of shark meat from sharks caught in the region. The shark meat trade is actually larger than the fin trade now, so understanding this trade is becoming increasingly important, we will also DNA barcode this trade to see what species are involved.”
As science advances, so too do the prospects for change. With enhanced sequencing technologies and improved regulatory frameworks, the journey towards sustainable shark conservation gains momentum. By empowering consumers with knowledge of species origins, governments can pave the way for informed choices, safeguarding both marine biodiversity and public health. The fate of sharks hangs in the balance, and only through informed choices, robust regulations, and international cooperation can we hope to preserve the oceans’ apex predators for generations to come.