Slavery at sea: Indian Ocean tuna fisheries face rising pressure over forced labor in supply chains

The global tuna industry has been long tainted by human rights abuses on the high seas, where as many as 128,000 fishers are ensnared in forced labor aboard vessels. Economic giants like the EU, the US, Australia, and Japan are leading consumers of the US$42 billion industry. But with complex and opaque supply chains in places hard to get to, modern slavery is rife. 

The Global Tuna Alliance’s (GTA) new campaign, Lives On The Line: Protect Fishers, urges the development of crew welfare standards to address documented human rights abuses in Indian Ocean tuna fisheries, where a larger chunk of catches come from areas beyond national jurisdiction compared to the Pacific region. Over 90% of tuna sold in the EU comes from the Indian Ocean, according to the Indian Ocean Tuna Commission (IOTC).

The typical demographics of fishers and vessel operators are telling of how socioeconomic disparities contribute to exploitation at sea.

“Many tuna crew members in the Indian Ocean region are migrant workers, often from countries such as Indonesia, the Philippines, and Sri Lanka. These individuals are frequently recruited through opaque labor networks, often lacking adequate contracts or legal protections. Vessel operators may be based in distant flag states, creating enforcement challenges and contributing to power imbalances,” Daniel Suddaby, executive director of GTA, tells Food Ingredients First.

“The combination of socioeconomic vulnerability, language barriers, and isolation at sea makes these workers at high risk to exploitation — including physical abuse, wage withholding, and excessive working hours without recourse.”

Human rights oversight

GTA comprises retailers and supply chain companies, which are now campaigning for the IOTC to develop comprehensive labor standards based on the International Labour Organization’s Work in Fishing Convention (ILO 188) at its 29th session.

The convention entitles all fishers to written terms and conditions of employment, decent accommodation and food, medical care, fixed working hours, repatriation, social protection, and safety on board. This is crucial as the human aspect of fisheries sustainability is often overlooked, according to GTA.

“Environmental issues in fisheries have traditionally been easier to quantify and regulate — like stock assessments or bycatch rates. In contrast, human rights abuses often occur out of sight, at sea, with limited visibility and legal oversight,” says Suddaby.

“This invisibility, coupled with fragmented regulatory responsibility across jurisdictions, means social issues have lagged in sustainability discussions.”

Links between forced labor and illegal fishing

Research has shown links between forced labor and illegal, unreported, and unregulated (IUU) fishing practices, as such vessels prioritize lowering costs, even if that involves engaging in human trafficking and modern-day slavery.

Therefore, the reputational fallout of ignoring these linkages is “significant” for retailers, especially as consumer interest in ethical consumption increases.

The typical demographics of fishers and vessel operators are telling of how socioeconomic disparities contribute to exploitation at sea.“Our understanding is that consumer demand for ethically sourced tuna is growing. Shoppers in markets across Europe, the US, and Asia are increasingly aware of the ethical dimensions of food. Some GTA partners are responding by embedding social responsibility into procurement policies,” reveals Suddaby.

“Some require transparency around recruitment practices, working conditions, and grievance mechanisms onboard vessels, adding to their existing ecological criteria for responsible sourcing.”

According to the Paris-based independent Institute for Sustainable Development and International Relations, the Indian Ocean industries are among the main suppliers to the world’s tuna can, steak, and sashimi markets. Moreover, nearly half of the catch is from overexploited or overfished stocks, posing risks for businesses interested in sustainable sourcing practices.

“Retailers risk losing consumer trust, and companies may face regulatory consequences, supply chain disruptions, or exclusion from ethical sourcing lists. Proactive steps are ethical imperatives and vital to maintaining brand trust.”

Overfishing and IUU fishing have lowered fish stocks and decreased the ROI for fishing companies and vessel captains, according to non-profit seafood sustainability consultancy Fishwise’s Roadmap for Improving Seafood Ethics.

Suddaby says the F&B industry is beginning to take steps to ensure that forced labor and other forms of exploitation do not go undetected in the tuna supply chain, but gaps remain.

“Current auditing systems often fail to detect forced labor, especially when self-reporting or dockside inspections are relied upon. More robust, on-the-water monitoring and legally binding regulations are urgently needed.”

GTA is not involved in individual supplier contracts as a pre-competitive collaboration. Therefore, it cannot predict whether major food retailers will require labor audits as standard in seafood contracts in the future.

“It is one of the reasons that we are advocating for regional fisheries management bodies like the IOTC to adopt binding crew welfare standards — to level the playing field and protect workers wherever they are,” says Suddaby.