A new study has, for the first time, identified the ownership and operations of refrigerated cargo vessels, known as reefers, that serve as floating ports for fishing vessels.

This new insight, published in Science Advances, addresses a critical gap in the traceability of the seafood value chain, long viewed as "a murky area" prone to illegal, unreported, and unregulated (IUU) fishing.

The study, led by Frida Bengtsson from the Stockholm Resilience Centre at Stockholm University, reveals that only 324 companies are responsible for all fish transshipment activities worldwide. Key players in this industry include China, Russia, and Greece, which play pivotal roles in managing these operations.

"It is a major step for more transparency," Bengtsson stated.

Reefers are integral to the seafood industry, facilitating the transfer of nearly a third of the global tuna catch, valued at approximately $10.4 billion annually. Beyond just transferring fish, these vessels also carry people, spare parts, and fuel between fishing boats and reefers.

Historically, the transshipment process has been criticized for its opacity, often obscuring the origin of seafood and enabling illicit activities. However, advancements in satellite data collection have allowed researchers to monitor vessel movements more effectively, though ownership information has remained elusive.

"Understanding who the beneficial owner of a vessel is provides new leverage and opportunity for improved governance and oversight of this practice," Bengtsson also explained. 

The collaborative research effort involved the Stockholm Resilience Centre, the Stanford Center for Ocean Solutions, and the University of British Columbia. It identified 569 operational reefers and traced them back to their 324 beneficial owners.

Remarkably, just 10 owners are accountable for nearly a quarter of all global transshipment events."We work with these key actors and get them to improve their operations, we could quickly enhance seafood's traceability and sustainability," said Bengtsson.

The study also maps reefer owners' operational zones, the gear used by fishing vessels they engage with, and the flags under which these vessels operate.