Stanford
Center for Ocean Solutions

Study reveals owners of ‘fish taxis’ and the vessels they support

Fewer than 400 companies own the refrigerated cargo ships that act as mobile ports for fishing boats. Understanding who owns these vessels could help combat seafood fraud.
|
Johannes Ernstberger, Stockholm Resilience Centre
Krill are transferred from a fishing vessel to the Pamyat Kirova – a reefer that's registered to Russia yet owned and operated by two companies in Greece – at the South Orkney Islands, Antarctica, in 2022. Image credit: Andrew McConnell/Greenpeace

Refrigerated cargo ships known as “fish taxis” or “reefers” function as mobile ports for fishing boats and can obscure the origin of seafood. For the first time, new research has identified the owners of all globally used reefers, the countries where they’re registered, and the fishing vessels they meet. 

The new article, published October 11 in Science Advances, shows that only 324 owners are responsible for all transfers of fish catch worldwide, with China, Russia, and Greece playing a significant role. 

“Fishing vessels do not act alone,” said study co-author Jean-Baptiste Jouffray, a Wallenberg Postdoctoral Fellow at the Stanford Center for Ocean Solutions. “Our study illuminates an often-overlooked side of the seafood sustainability discourse – that is, the ownership of support vessels indispensable to fishing operations."

Lead author Frida Bengtsson of the Stockholm Resilience Centre at Stockholm University called the work “a major step for more transparency.”

The transfer of catches, people, spare parts, and fuel between a fishing vessel and a reefer – known as transshipment – has been repeatedly described as opaque and associated with illegal activities, as it can enable the transfer of illegally caught species or obscure the origin of seafood. 

These transfers play a significant role in the seafood industry. For instance, nearly a third of global tuna catch (worth US $10.4 billion) is transhipped annually. 

Mapping vessel activity

The new study includes an interactive, online tool that combines satellite and other public data sources to pinpoint at-sea encounters between reefers and fishing vessels from 2017 to 2022. Data include a given vessel’s location, ownership, and the country that it’s registered to, also known as its “flag state.” Stanford Center for Ocean Solutions senior data research scientist Shinnosuke Nakayama led development of the tool. 

“These types of data can be hard to capture effectively with static figures in print,” said Nakayama. “By offering an interactive format, we give readers a more dynamic way to engage with the research findings and think about how these data might inform next steps for improving the transparency of seafood supply chains,” said Nakayama.

Explore the tool


Fishing practices at sea used to be out of sight and out of mind, but recent advancements in the collection and sharing of satellite data at the vessel level mean that researchers and the public can now see where vessels operate. A missing piece, however, has been knowing who owns the reefer vessels used in the transshipment of seafood.

“Understanding who the beneficial owner of a vessel is provides new leverage and opportunity for improved governance and oversight of this practice,” explains Bengtsson.

In this study, researchers from the Stockholm Resilience Centre, the Stanford Center for Ocean Solutions, and the University of British Columbia have identified 569 reefers currently in use in the fishing industry and their 324 beneficial owners. Just ten of these owners account for almost a quarter of all transshipment events globally. Considering the volumes of seafood that are transshipped, this is a surprisingly low and very manageable number of actors.

“If we work with these key actors and get them to improve their operations, we could quickly improve the traceability and sustainability of seafood,” said Bengtsson.

The new research has also mapped where reefer owners operate their vessels, the gear used by the fishing vessels they meet, and the flags involved. All this data can now be freely accessed and visualized using an online tool. This improved transparency can help NGOs, insurance companies, and financial actors interested in creating stronger incentives for sustainable behaviors at sea. 

This story was adapted from an article originally published by the Stockholm Resilience Centre.

Other co-authors from the Stanford Center for Ocean Solutions include Deputy Director Elizabeth Selig and Lead Scientist Colette Wabnitz, who is also associated with The University of British Columbia. Other co-authors are affiliated with the Stockholm Resilience Centre at Stockholm University and the Anthropocene Laboratory at the Royal Swedish Academy of Sciences.

The research was supported by the Marianne and Marcus Wallenberg Foundation, Knut and Alice Wallenberg Foundation, FORMAS, The David & Lucile Packard Foundation, and The Walton Family Foundation.  

Media Contacts

More News Topics

News story Curbing Illegal Fishing

More News