One of my favorite places when I lived in Tokyo was my neighborhood sushi bar. I'd take a seat, and the chef would prepare fish fresh from the Tsukiji market in central Tokyo. A specialty was the raw octopus, delivered on a bed of lightly vinegared rice. I liked sushi before I moved to Japan; now I love it.
I'm hardly alone, which is bad news for the world's oceans. Partly because of the rising global demand for sushi, we're fast fishing out our seas, with some researchers estimating that if we don't change the way we harvest the oceans, all the commercial fisheries in the world could collapse as early as 2048. That could mean no more California rolls in your local supermarket.
Fortunately, scientists are figuring out ways to fish sustainably. One method is a quota system that guarantees individual fishermen or cooperatives a prearranged share of the total catch for, say, Alaskan halibut. These catch shares eliminate the incentive to overfish. And a recent study in Science found that catch shares can halt fishery collapses--defined as fish populations falling to 10% of historic highs--and even reverse the trend over time. "It's truly a win-win situation," says Steven Gaines, a marine biologist at the University of California at Santa Barbara and one of the study's co-authors.
Consumers also can help save the seas--through the fish they buy. To that end, California's Monterey Bay Aquarium, along with the Blue Ocean Institute and the Environmental Defense Fund, is coming out with pocket guides to sustainable sushi. The groups base their ratings on the health of a wild fish's population (the popular bluefin tuna is restricted), along with the impacts of fish-farming operations. (Fast-growing oysters can be farmed sustainably, but salmon can't.) They also take into account fishing practices: catching bigeye tuna with thousand-hooked longlines can result in the unintended death of nearby fish. The hope is that by voting with their chopsticks, consumers can motivate businesses to act more sustainably. Unfortunately, my beloved octopus is now a no-go--but at least I'll always have Tokyo.