Though most of humanity doesn’t realize it, our survival depends on our oceans. During the past couple of centuries we’ve overfished and polluted oceans to the point where many aquatic species are on the verge of collapse. But most of us love wild seafood and have no intention of curtailing our appetite. That’s why the sustainable seafood movement is essential. In the U.S. it’s been led by the Monterey Bay Aquarium; the Canadian counterpart is the Vancouver-based Seafood Watch but the true stars of the movement there are the top chefs who insist on serving fish whose stocks are not depleted. Last fall I spent a few days in Vancouver tracing sustainable seafood from fishing boats to markets to the city’s finest restaurants.