Britain ’s biggest retailer , Tesco , has warned John West that it will stop stocking its canned tuna if the company does not change its cruel fishing practices . In Tesco’s own-brand tuna, so-called “Fish Aggregating Devices” (or FADs) are already banned because they harm all kinds of marine life, including sharks. John West , which is owned by tuna giant Thai Union , uses ‘ fish aggregating devices ’ which are harmful to other kinds of marine life , instead of the more sustainable pole - and - line method . Tesco ’s threat could be a damaging one to Thai Union , as the UK is the second biggest commercial fish consumer in the world . The company told Greenpeace in 2011 that it would make the switch to sustainable fishing by the end of 2016 .
Britain ’s biggest retailer , Tesco , has warned John West that it will stop stocking its canned tuna if the company does not change its cruel fishing practices . John West , which is owned by tuna giant Thai Union , uses ‘ fish aggregating devices ’ which are harmful to other kinds of marine life , instead of the more sustainable pole - and - line method . Tesco ’s threat could be a damaging one to Thai Union , as the UK is the second biggest commercial fish consumer in the world . The company told Greenpeace in 2011 that it would make the switch to sustainable fishing by the end of 2016 .