For decades, the European fishing industry has held unmatched dominance in Indian Ocean tropical tuna harvesting, centered around a fleet of large purse seiners—massive vessels with the capacity to hold up to 1.8 million kilograms of tuna in a single trip. Dozens of these ships patrol the Indian Ocean’s waters, catching skipjack, yellowfin and bigeye tuna that eventually end up as canned products on grocery store shelves across the globe. But when Jess Rattle, head of investigations at the London-based environmental non-profit Blue Marine Foundation, spotted numerous purse seiners operating under the flags of Mauritius, Tanzania and Oman, she began questioning the true ownership of these vessels.
“Our core goal was to unpack who actually holds ownership of these vessels,” Rattle explained. “Were they the property of the coastal states whose fishing quotas they were using, or did the true ownership trace back to European Union entities?”
A groundbreaking joint investigation released Thursday by Blue Marine Foundation and global corporate investigations firm Kroll, shared exclusively with The Associated Press ahead of publication, now lays bare the full scale of European access to Indian Ocean tuna stocks. The probe finds that European companies currently take one-third of all tropical tuna caught in the region—a revelation that comes as yellowfin and bigeye tuna populations remain strained, still working to recover from historic overfishing.
Rattle’s investigation confirms that European firms access these extra quotas by reflagging their vessels to five coastal Indian Ocean nations: the Seychelles, Mauritius, Kenya, Tanzania and Oman. This common, though not illegal, practice has allowed the European-controlled fleet to expand to more than 50 purse seiners and support vessels, and maintain high catch levels even as the EU made public commitments to reduce overall tuna harvesting to support stock recovery.
The findings arrive on the eve of the annual gathering of the Indian Ocean Tuna Commission (IOTC) in the Maldives, a summit that brings together the EU and 20 member nations with commercial stakes in the region’s tuna industry. While reflagging is widespread across the global fishing sector, it creates significant barriers for regulators and independent observers seeking to accurately measure European firms’ impact on vulnerable tuna stocks. True parent company ownership is often hidden behind complex layers of shell companies and opaque foreign registry systems, which Rattle and Kroll’s team spent months untangling to map the full extent of hidden European control.
While European firms have operated under the Seychelles’ flag for decades, Rattle notes that growing reflagging to Oman and Kenya is a new, unreported trend. In response to the investigation’s findings, Europeche Tuna Group, the trade body representing the European tuna industry, framed its cross-border partnerships as a net positive for regional economies. “Our industry’s relationships with coastal African and Indian Ocean nations are built on decades of long-term investment and deep local collaboration,” said group spokesperson Anne-France Mattlet. She added that European operators contribute to local economies through tax and fishing license payments, investment in local infrastructure, and offloading catches at regional ports and canneries. Mattlet also confirmed the investigation’s count of more than 50 European-linked purse seine and support vessels operating in the Indian Ocean, including those flying non-EU flags.
A spokesperson for the European Commission, Maciej Berestecki, noted that reflagging is a private commercial decision made independent of EU public authorities, and that the bloc does not advocate for or represent the interests of vessels registered to non-EU countries. “The EU has worked, and continues to work, to the fullest extent to promote and enforce binding catch limits that support sustainable tuna management,” Berestecki said in a statement.
European dominance in the Indian Ocean tuna trade is not new: Spanish and French tuna companies first introduced large purse seine technology to the region in the 1980s, allowing the fleet to rapidly scale annual catches and establish a dominant market position. But this outsized influence has repeatedly brought the EU into conflict with coastal nations seeking greater control over fishing activities in their adjacent waters. Five years ago, as yellowfin populations plummeted, the Maldives publicly accused the EU of refusing to table meaningful proposals to cut catch quotas during a heated IOTC meeting. In 2023, the bloc opposed an Indonesian proposal for targeted restrictions on purse seine fishing that passed with support from 15 other IOTC member states.
In recent years, the IOTC has implemented new binding management rules designed to rebuild vulnerable yellowfin and bigeye tuna populations, which have started to show early signs of recovery. As part of these measures, the EU agreed to cut yellowfin tuna catches for EU-flagged vessels by 21%. Glen Holmes, a senior officer with the Pew Charitable Trusts, says these mandatory cuts are likely pushing European firms to turn to reflagging to tap into other nations’ quotas and maintain their historic catch volumes. Holmes, alongside partners from Pew, Global Fishing Watch and other conservation groups, is pushing for stricter ownership transparency requirements for all fishing fleets operating in the Indian Ocean.
Foreign reflagging has long been a point of contention for transparency advocates, who argue the practice enables weak oversight of vessel activities. The phenomenon mirrors trends seen in the “shadow fleet” of sanctioned oil tankers, which frequently change names and flags to hide true ownership and evade international sanctions. Certain coastal states have become known as “flags of convenience,” offering low registration fees and lax enforcement of international fishing and trade rules, in many cases due to limited resources to patrol and regulate distant fleets.
A January 2024 investigation by environmental group Oceana already documented widespread reflagging of European-owned fishing vessels to non-EU nations, including some the EU itself has accused of ignoring illegal fishing activity. Oceana is calling on EU member states to mandate collection and public publication of full beneficial ownership data for all European-controlled fishing vessels, regardless of the flag they fly. Vanya Vulperhorst, Oceana’s Europe director for illegal fishing campaigns, says this change would help the EU enforce its own existing laws, which bar European individuals and companies from profiting from illegal fishing activity. It would also reveal the true size of the European fishing footprint: “What our investigation found last year is that the actual size of the European fleet, when you add all the non-EU flagged vessels controlled by European firms, doubles the official count,” Vulperhorst said.
This reporting was supported by funding from the Walton Family Foundation, with The Associated Press holding sole editorial responsibility for all content.









