A groundbreaking investigation by researchers at the University of North Carolina at Chapel Hill has revealed alarming truths about the origin and labeling of shark meat sold within the United States. Using advanced DNA barcoding techniques, the team meticulously analyzed 29 shark meat samples purchased from various grocery stores, seafood markets, and online vendors. The results expose a disconcerting reality: over 90% of these products were either ambiguously labeled or mislabeled entirely, concealing the true identity of the shark species involved. This revelation underscores significant concerns regarding consumer transparency, conservation efforts, and public health risks associated with shark meat consumption.
The study’s genetic analyses identified an astonishing variety of eleven distinct shark species among the samples tested. Strikingly, several of these species are listed as critically endangered by the International Union for Conservation of Nature (IUCN), including the great hammerhead (Sphyrna mokarran) and the scalloped hammerhead (Sphyrna lewini). Both species are apex predators essential to marine ecosystems, and their precipitous population declines have raised red flags within conservation circles worldwide. Nevertheless, these species’ meat was found being marketed and sold to American consumers, frequently labeled generically simply as “shark” or inaccurately as “mako shark.”
This lack of precise labeling not only obscures critical conservation issues but also exacerbates human health risks. Hammerhead sharks, particularly the great and scalloped varieties, are known to bioaccumulate dangerously high levels of mercury, a potent neurotoxin. The consumption of mercury-laden seafood is especially risky for vulnerable populations such as pregnant women and children, leading to irreversible neurological damage and developmental problems. Unfortunately, the ambiguous labeling identified in this study strips consumers of the vital information they need to make informed choices and avoid these hazardous products.
Savannah Ryburn, Ph.D., the lead author of the study and co-instructor of the seafood forensics course responsible for the research, emphasized the intersection of ecological and health consequences stemming from this mislabeling. “Consumers are not given the clarity necessary to select what they are ingesting,” Dr. Ryburn noted. “Products deriving from scalloped and great hammerhead sharks, which have exceptionally high mercury concentrations, are often sold under vague labels. This prevents individuals from avoiding dangerous exposures.”
Delving deeper into the labeling practices examined, the researchers found that 27 out of the 29 products lacked any specific species designations. Only two samples bore species names, and of these, one was definitively misidentified upon DNA analysis. This pervasive ambiguity reveals a glaring deficiency in regulatory oversight and accountability among U.S. seafood distributors and sellers. Without enforceable mandates on precise species identification, consumers remain vulnerable to deception, inadvertently perpetuating exploitation of endangered marine fauna.
John Bruno, Ph.D., distinguished professor and co-instructor of the seafood forensics course, underscored the urgent need for regulatory reform. According to Dr. Bruno, “The United States must implement stringent requirements compelling seafood distributors to furnish species-specific labeling. Such transparency is foundational to both conservation agendas and consumer safety.” This call aligns with broader global efforts to enforce sustainable seafood practices and combat illegal, unreported, and unregulated (IUU) fishing that contributes to biodiversity loss.
The researchers drew attention to another troubling aspect: the price at which some of these endangered sharks’ meat is sold. Despite their rarity and ecological importance, samples of hammerhead shark meat were found on the market for as low as $2.99 per pound. This disparity suggests a systemic undervaluing of endangered marine species, reflecting lax enforcement of wildlife protection laws and market pressures driving unsustainable exploitation.
The implications of this study extend beyond environmental conservation and public health concerns—they touch on ethics in consumer markets and the responsibilities of industry stakeholders. Without transparent supply chains and verified product information, consumers are rendered powerless to direct demand towards sustainable seafood options. Moreover, the health ramifications of consuming mislabeled, mercury-rich shark meat amplify the urgency for action from both regulators and the seafood industry.
Beyond the United States, this investigation contributes to a growing body of research employing DNA barcoding to evaluate seafood mislabeling worldwide. Molecular identification technologies have increasingly become vital tools in uncovering discrepancies between product labels and genetic identity, illuminating the scale of seafood fraud, especially in species identification of fish and shellfish. This study serves as a clarion call for integrated enforcement of labeling standards, leveraging technological advances to protect fragile marine ecosystems and consumer health alike.
DNA barcoding, the genetic technique central to this research, involves analyzing a short genetic marker in an organism’s DNA to ascertain its species. It is a powerful method for verifying seafood authenticity, overcoming the challenges of species identification that arise when fish are processed and stripped of distinguishing morphological characteristics. In the context of shark meat, which often appears as fillets or minced products, DNA barcoding emerges as the only definitive tool to ensure accurate labeling.
The researchers also highlight the necessity of educating consumers about the risks associated with consuming shark species known to accumulate heavy metals. Public awareness campaigns, combined with enforceable labeling policies, could empower individuals to make safer dietary choices and exert market pressure on vendors to prioritize sustainable, transparent sourcing. This multidimensional approach is vital to addressing the intertwined challenges of public health, conservation, and seafood fraud.
In conclusion, this incisive study shines an essential spotlight on the hidden realities of shark meat trade in the United States. It reveals systemic lapses in labeling regulations that facilitate the sale of endangered species’ meat and expose consumers to significant health risks. Through DNA barcoding and rigorous sampling, the research team has provided indispensable evidence supporting the call for species-specific labeling requirements, enhanced regulatory oversight, and consumer education. This work not only advances scientific understanding but also advocates for ethical and responsible practices in seafood markets, championing both biodiversity conservation and consumer protection.
Subject of Research: Seafood mislabeling and conservation of endangered shark species
Article Title: Sale of critically endangered sharks in the United States
News Publication Date: 10-Sep-2025
Web References: https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2025.1604454/abstract#supplementary-material
References: DOI: 10.3389/fmars.2025.1604454
Image Credits: Savannah Ryburn
Keywords: Public health; Marine fishes; Food safety
