The researchers describe illegal fishing as a transnational system sustained by weak governance, opaque ownership structures, harmful government subsidies, and supply chains that make it difficult to determine where seafood comes from. “Illegal fishing is not a fringe activity, but a systemic feature of the global seafood economy,” said lead author Philippe Le Billon, a professor in UBC’s Department of Geography and School of Public Policy and Global Affairs. The study argues that illegality remains profitable because the potential rewards are high, while the probability of detection, prosecution, and meaningful punishment is often low.

The geographic distribution of illegal fishing is highly uneven. Although unlawful activity occurs in waters around the world, roughly two-thirds of the illicit seafood trade by value originates in West Africa, East Asia, and Southeast Asia. These regions often combine rich marine resources with limited enforcement capacity, making them particularly vulnerable to incursions by distant-water fleets. Fishing is also central to local food security, employment, and national economies, so the depletion of fish stocks can produce consequences that extend far beyond environmental damage.

The seafood caught illegally does not remain in the regions where it is harvested. Much of it is eventually consumed in wealthier markets in North America, Europe, and East Asia. This creates a global imbalance in which coastal communities and developing states absorb the ecological and social costs, while profits move through international traders, processors, and retailers. UBC fisheries economist Rashid Sumaila said the pattern illustrates how the benefits of illegal fishing often flow elsewhere, while the losses are experienced by communities that depend directly on the ocean.

A central finding of the analysis is that illegal seafood can be laundered through multiple stages of the supply chain. At-sea transshipment allows fishing vessels to transfer catches to refrigerated cargo ships without returning to port, reducing opportunities for inspection and obscuring the location where fish were caught. Fraudulent catch certificates, species mislabeling, and the mixing of illegal and legal fish can further disguise the origin of seafood. Once the products enter processing facilities, ports, and distribution networks, separating lawful catch from illicit catch becomes technically and legally difficult.

Vessel ownership can be equally difficult to trace. Large fishing operations may use layered corporate structures, shell companies, and flags of convenience to hide the individuals or businesses that ultimately control vessels. Ships can also be re-registered under new flags or moved between corporate entities to evade sanctions and weaken accountability. According to the researchers, these arrangements exploit gaps between national jurisdictions. A vessel may be owned in one country, registered in another, fish under the authority of a third, and land its catch in a fourth before the seafood reaches consumers through several additional markets.

The study identifies fuel and other capacity-enhancing fisheries subsidies as important factors that can make destructive and illegal operations financially viable. Subsidized fuel lowers the cost of traveling to distant fishing grounds and allows industrial fleets to remain at sea for longer periods. This can intensify competition with small-scale and Indigenous fishers, whose vessels generally lack comparable financial support or technological capacity. The researchers argue that reducing illegal fishing will require more than increasing surveillance; it will also require reforming the economic incentives that make overcapacity and unlawful activity profitable.

New technologies are improving the ability to detect suspicious behavior. Satellite-based vessel tracking can reveal fishing activity in restricted areas, while artificial intelligence can identify unusual movement patterns, gaps in tracking data, or possible rendezvous between fishing and transport vessels. Electronic monitoring systems, including onboard cameras and sensors, can provide evidence about catches and fishing practices. However, technology cannot close the enforcement gap on its own. Inconsistent monitoring, weak port inspections, inadequate penalties, and political interference can prevent evidence from leading to prosecution. Powerful commercial or geopolitical interests may also limit how aggressively authorities act.

The consequences reach beyond declining fish populations. Illegal fishing can reduce government revenues, undermine legitimate seafood businesses, increase food and nutritional insecurity, and intensify pressure on coastal livelihoods. The researchers also highlight labor abuses aboard fishing vessels, including unsafe working conditions and a high risk of forced labor for tens of thousands of crew members, particularly on vessels operating far from public oversight. In some contexts, illegal fishing is connected to corruption, smuggling, and maritime insecurity, transforming what may appear to be an environmental offense into a broader governance and human-rights crisis.

The authors say effective reform must combine stronger port-state controls, mandatory electronic vessel identification, transparency about beneficial ownership, and closer international cooperation. Policies should also protect small-scale and Indigenous fisheries and support co-management systems that give local communities a meaningful role in regulating marine resources. Recent developments offer limited grounds for optimism: the World Trade Organization rectified its first fisheries subsidies agreement in 2025 and is working toward a follow-up agreement, while the High Seas Treaty entered into force on January 17, 2026. China has also become a party to the Agreement on Port State Measures. Yet the researchers stress that treaties and surveillance systems will matter only if governments, companies, and consumers push consistently for enforcement. Illegal fishing persists in the darkness created by fragmented responsibility; exposing that system is the first step toward dismantling it.

Subject of Research: Industrial-scale illegal and unreported fishing, illegal seafood markets, fisheries governance, supply-chain laundering, and the environmental and social impacts of illicit fishing.

Article Title: Casting light on the workings of illegal fishing markets

Web References: https://doi.org/10.1073/pnas.2512081123

References: Proceedings of the National Academy of Sciences; DOI: 10.1073/pnas.2512081123

Keywords: Illegal fishing, unreported fishing, overfishing, seafood markets, fisheries subsidies, marine conservation, ocean governance, supply-chain transparency, transshipment, forced labor, food security, port-state controls, sustainable fisheries, maritime law, international cooperation

The answer, researchers say, is unexpectedly unclear. Shark-finning regulations showed no statistically significant effect on international exports, imports, domestic consumption or the number of trading partners involved in shark-product commerce. The findings do not prove that finning regulations are ineffective, but they suggest that the policies have not produced a detectable transformation in global trade flows. Published in Nature Communications, the study is the first to examine the relationship between shark-finning rules and international trade using a dataset capable of linking what fisheries catch with what countries buy and sell.

“ We evaluated a lot of different things and found that there’s really no clear-cut answer to our research question,” said co-lead author Echelle Burns, a project scientist at the University of California, Santa Barbara’s Environmental Markets Lab. The research team included scientists from UC Santa Barbara, The Nature Conservancy and Renmin University of China. Their analysis addresses a longstanding problem in conservation science: fishing activity and commercial trade are typically recorded in separate systems, measured in different units and rarely connected in a way that allows researchers to follow a product from ocean capture to final market.

Shark-finning rules are designed to stop a particularly wasteful practice. In conventional finning operations, fishermen remove a shark’s valuable fins and discard the remaining carcass, often while the animal is still alive. Since fins are more valuable by weight and take up less space than whole sharks, retaining carcasses can alter the economics of fishing. Regulations therefore commonly require vessels to keep fins attached to the body or to land fins and carcasses in specified ratios. In theory, these requirements should make shark targeting less profitable and reduce the number of sharks entering the supply chain.

The economic reality, however, is more complicated. A rule that requires sharks to be landed whole may increase the supply of shark meat, liver or oil even as it reduces the incentive to collect fins alone. That additional meat could stimulate new demand or encourage markets to expand into products that were previously less important. “If a country requires that fishing vessels must land sharks with their fins still attached, the influx of shark meat supply could stimulate a market expansion for shark products,” said co-lead author Kaiwen Wang, an economist at Renmin University of China. Such effects could offset, or even obscure, the intended impact of a regulation.

To analyze these possibilities, the researchers used the Aquatic Resource Trade in Species dataset, known as ARTIS, maintained by the University of Washington and released in 2024. The database tracks aquatic products through international trade networks and supply chains, allowing scientists to connect fisheries data with commercial records. The team combined ARTIS with econometric methods, which are statistical tools used to estimate the effects of policies while accounting for differences between countries and changes over time.

The researchers compared trade and domestic-consumption data from countries before and after they adopted shark-finning regulations. They then compared those changes with countries that had not introduced such rules, creating a control group. This approach, often used in policy evaluation, helps distinguish the potential effect of a regulation from broader forces such as changing consumer preferences, shifts in fishing capacity, economic growth or disruptions in international commerce. The analysis examined several outcomes, including imports, exports, domestic use and the number of trading relationships maintained by each country.

Across those measures, the results did not reveal a statistically significant change associated with the adoption of finning regulations. In scientific terms, the observed differences were not large or consistent enough to rule out the possibility that they arose from normal variation or other factors unrelated to the policies. The finding does not mean that every regulation failed, nor does it show that finning bans have no local benefits. Instead, it indicates that their overall influence was not clearly visible in the global trade data examined by the study.

The researchers emphasize that a null result is itself important. “This sort of null result can initially be disappointing for us as researchers,” said senior author Gavin McDonald, a senior project scientist at UC Santa Barbara’s Environmental Markets Lab. “But it is still incredibly important to share these types of findings.” A lack of measurable change can expose weaknesses in assumptions about how conservation policies work and prevent governments from relying on simplified narratives. The result also raises practical questions about enforcement, illegal fishing, reporting accuracy and whether traders can redirect products through alternative markets or trading partners.

Shark conservation is further complicated by differences among species and by the interaction of multiple policies. A finning restriction may operate alongside retention bans, import prohibitions, fishing-gear rules, catch limits and international trade controls, making it difficult to isolate the effect of any single measure. Some species may be retained for meat after capture, while others may be discarded or landed under entirely different rules. The study’s authors say that connecting regulation, fishing behavior and trade is essential for designing more effective interventions. For consumers and policymakers, the central message is striking: protecting sharks may require more than banning the most visible form of waste. It may require monitoring the entire supply chain, from the moment a shark encounters fishing gear to the point where its fins, meat or other products reach a market.

Subject of Research: The relationship between shark-finning regulations and global trade, domestic consumption, and supply-chain dynamics for shark products.

Web References: https://news.ucsb.edu/people/echelle-burns ; https://news.ucsb.edu/people/gavin-mcdonald ; https://news.ucsb.edu/2025/021801/sharks-are-dying-alarming-rates-mostly-due-fishing-retention-bans-may-help

References: Nature Communications, DOI: 10.1038/s41467-026-75625-1

Keywords: shark finning, shark conservation, fisheries management, international trade, marine conservation, regulatory policy, shark products, fisheries, conservation science, supply chains, ARTIS dataset, ocean policy