Almost all major UK supermarkets are selling canned tuna that could have been caught using a harmful fishing method, according to campaigners.
The Blue Marine Foundation, alongside environmental groups Bloom and Greenpeace UK, carried out a six-month investigation into fishing practices and policies in supermarket supply chains.
They found huge disparities between the sourcing policies of their own-label canned tuna and the brand-name tuna they sell.
Most supermarkets were found to be selling tuna caught using drifting aggregating devices (FAD) – a type of trackable fishing gear that drifts freely around the ocean, gathering tuna beneath them.
But FADs are controversial as they catch tuna juveniles before they have had the chance to breed, leading to overfishing, as well as endangered, threatened and protected species.
The devices have also been known to drift through marine protected areas and other countries’ exclusive economic zones while the gear is often discarded or lost in the sea, causing plastic pollution and ecological damage.
The environmental groups said Marks and Spencer was the only one of the top 10 supermarkets who could demonstrate that none of the canned tuna sold in its stores was caught using this method.
Several other retailers including the Co-op, Waitrose, Sainsbury’s and Morrisons all have tuna sourcing policies that clearly prohibit the use of drifting FADs.
However, this includes only their own-label products with all four supermarkets also found to be selling brand-name tuna such as John West and Princes.
The groups claim these brands source tuna from fleets that use drifting FADs in the Indian Ocean.
The investigators found Iceland sells only the brand-name tuna.
Meanwhile, several other retailers, including Tesco and Aldi, reference the Marine Stewardship Council (MSC) in their own-label sourcing policy.
However, the group said this does not guarantee that drifting FADS were not used, citing a recent report from Bloom that found more than half of the tuna certified as sustainable by the MSC comes from fisheries that rely on FADs.
The three organisations are calling on UK retailers to stop selling tropical tuna caught around drifting FADs in the Indian Ocean by not entering into any new supply agreements for tuna caught in this way.
They urged the retailers to extend this policy to both own-label tuna and brand-name tuna products.
Jess Rattle, head of investigations at Blue Marine Foundation and the author of the report, said: “Drifting FADs are a scourge that do untold damage to fragile marine habitats and important tuna stocks.
“UK retailers are well aware of this – many of them acknowledge how harmful drifting FADs are in their own-label sourcing policies, but then turn a blind eye to the tins of brand-name, FAD-caught tuna on their shelves.
“UK consumers deserve better, and we call on retailers to stop selling tuna caught using drifting FADs by not entering into any new supply agreements for tuna caught in this way.
“This is especially urgent in the Indian Ocean where governments representing commercial fleets choose to object to drifting FAD management measures put in place to protect overfished stocks”.
A Waitrose spokesperson said: “All our canned own-label tuna is pole-and-line caught and MSC certified, helping preserve fish stocks for future generations. We only stock brands that use the pole-and-line method or are MSC certified.”
A Tesco spokesperson said: “None of our own brand tuna is sourced from the Indian Ocean and we do not source any of the tuna for our own brand products using Fish Aggregating Devices. We continue to advocate for robust management at RMFO level through our industry partnerships.
“We are committed to promoting the sustainable management of marine fisheries and aquaculture, in order to ensure future generations of customers can enjoy seafood in the way we do today. We are members of the Global Tuna Alliance and also work in partnership with NGOs such as WWF, and our suppliers to ensure we are a trusted voice in marine sustainability.”
David McDiarmid, corporate relations director at Princes, said: “Princes sources tuna from purse seine – with and without FADs – and pole and line methods, and supports conservation measures taken by RFMOs to improve FAD management, monitoring and the sustainability of tuna stocks, based on scientific advice.
“Princes has committed to 100% Marine Stewardship Council certified tuna by the end of 2025. The MSC is the only wild-capture fisheries certification and ecolabelling program that meets best practice requirements set by both the United Nations Food and Agriculture Organisation (UNFAO) and ISEAL, the global membership association for sustainability standards.”
The PA news agency has contacted Co-op, Sainsbury’s, Morrisons, Aldi and Thai Group – owner of John West – for comment.