Yesica Fabiana Levianco steers her small wooden boat while her partner, Paulo Vera Perez, dives into the cold ocean waters off the coast of southern Chile.

Within a few hours the couple, both in their mid-40s, has filled the boat with shellfish, sea urchins, mussels and crabs that Levianco will sell at the market in Melinka, the main island in the Guaitecas Archipelago.

Even a few years ago, such a haul would have been unthinkable.