Imagine you and your family have relied on a food source for generations - until big foreign companies turn up in your backyard and start plundering it.
This is what’s happened with tuna in coastal communities around the world.
Take the Pacific, which until recently boasted the world's last remaining healthy tuna stocks. This made the region a magnet for foreign fishing companies, who have arrived with their giant boats and foreign crews and devastated local fisheries.
The result? Pacific tuna stocks declining, with some already on the brink of collapse, people without jobs and in some cases, local families having to survive on unhealthy imported food.
The same thing has happened in other parts of the world, where the bulk of tuna fishing is being done by large-scale commercial fleets from wealthy industrialized countries, who don’t care about local food supplies, local jobs or local economies.
Some tuna companies are working with and supporting local communities. To find out which brands are worth buying, check out our tuna ranking guides.