If you're an environmentally-minded consumer, a walk through the seafood section of your local supermarket probably fills you with angst. After all, the oceans are an integral part of life on Earth. Among other things, they support the existence of 50 percent of the planet's species and they also play an important role in climate and weather systems.
But the aquatic environment is under attack from multiple threats. Human-driven climate change, which is raising ocean temperatures and reducing the water's oxygen content, is wreaking havoc for the ecological balance by forcing fish to abandon old habitats and search for cooler waters. Noise from ships interferes with marine animals' ability to communicate, find mates, and hear and avoid predators.
But perhaps the biggest menace to aquatic biodiversity is overfishing, thanks to the advent of giant "factory" ships that hunt down schools with sonar and drag enormous nets from which there is no escape. According to the environmental organization Greenpeace, since large-scale industrial fishing began in the 1950s, populations of the big tasty fish that we love to cook and eat -- like tuna, swordfish, marlin, cod, halibut, skate and flounder -- have been reduced by 90 percent. At the rate that we're eating our way through the oceans, fish may eventually become a rare and expensive delicacy.
Does that mean that you have to give up seafood and learn to like tofu? Not necessarily. It's possible to keep this valuable source of protein and Omega-3 fatty acids in your diet without doing too much harm to the oceans, if you're careful about what varieties of fish you buy and who you buy it from. Groups like the Environmental Defense Fund not only are pushing the fishing industry to adopt more sustainable practices, but they've created numerous printed guides and Web sites to help you make responsible choices at the fish counter.
What is Environmentally-Friendly Seafood?
Environmental groups say the general idea is to eat only aquatic species that haven't been drastically depleted by overfishing and whose harvesting doesn't disrupt ocean ecosystems. And while environmentalists see sustainable aquaculture as a promising way to provide people with seafood, they also advise people to stay away from certain varieties of farm-raised fish because their cultivation comes with an environmental cost. Farms that raise big predator fish like salmon, for example, feed them massive quantities of smaller wild fish like anchovies and mackerel, which leads to overfishing of those species.
Here are some general guidelines suggested by environmental organizations:
- Stay away from the big, scary predator fish (swordfish, tuna, sharks, salmon). These are the species that have been the most seriously depleted, and from a health standpoint, they're the ones with the highest levels of toxins from pollution. You can make an exception for Alaskan wild salmon and albacore tuna from the Pacific Northwest and British Columbia, where the fisheries are well-managed.
- Small is good. The runts of the food chain -- sardines, anchovies, clams, mussels and oysters -- reproduce readily and aren't in as much danger of depletion. They're also less likely to contain high toxin levels from pollution, since they have shorter lifespans.
- Know which species are at risk. Chilean sea bass might sound tasty (even tastier when you don't call them by their other name, toothfish), but they're in severe decline from overfishing. To make matters worse, the longlines used to catch them often snag endangered albatrosses.
- Look at the place of origin. The U.S. and Canadian fishing and aquaculture industries aren't perfect, but they do face regulatory scrutiny on environmental and health issues, and they're making an effort to adopt more sustainable practices. If the seafood comes from Central or South America or Asia, where environmental regulation and health standards are less stringent, be cautious.
- Look for seals of approval. The Marine Stewardship Council (MSC), a UK-based group, certifies fisheries for using sustainable, environmentally benign methods.
Most Eco-friendly Fish to Eat
Here's a recent edition of the Monterey Bay Aquarium's "Super Green List" of seafood that are both sustainable and safe to eat:
- Albacore tuna (troll- or pole-caught, from the United States or British Columbia)
- Freshwater coho salmon (farmed in tank systems, from the United States)
- Mussels (farmed)
- Oysters (farmed)
- Pacific sardines (wild-caught)
- Pink shrimp (wild-caught, from Oregon)
- Rainbow trout (farmed)
- Salmon (wild-caught, from Alaska)
- Spot prawns (wild-caught, from British Columbia)