Which Are the Healthiest and Most Sustainable Fish to Eat? Here Are Three Ways to Find Out

Choosing a fish was not always this difficult. Once upon a time, all an eater had to do was see what was available in the fish market or on the menu and compare the choices based on taste and price. Nowadays, a conscientious seafood eater must begin by consulting one of the various guides put out by marine conservation groups such as the Monterey Bay Aquarium's Seafood Watch or Blue Ocean Institute to see which species aren't overfished or contain high levels of mercury or any other of a number of hazards. Sustainable seafood guides have been around for a while, but recently, a new one appeared, created by the organization Food and Water Watch. Given the vast amount of information and effort required to make a comprehensive seafood guide, why did they decide to make a new one when several others already exist?

As it turns out, Food and Water Watch's guide is a little bit different from the others already in existence. Monterey Bay Aquarium's communications director Ken Peterson says, "Our starting point is healthy ocean ecosystems. What is the impact of each type of fish whether wild or farmed? Based on the best science available, we look at a number of factors that we think are the most important to healthy oceans to produce our guide."

A look at Monterey Bay Aquarium's guide shows that it also includes important human health information (such as high mercury levels in fish) when applicable. Food and Water Watch, on the other hand, asks which seafood choices are best for health, the environment and the community. Its guide examines human health implications and socio-economic implications of each seafood as well as environmental impact.

The structures of the various guides differ as well. Both Monterey Bay Aquarium and Blue Ocean Institute rate seafood as Red, Yellow and Green. For Monterey Bay Aquarium, green means "Best Choice," yellow means "Good Alternative," and red means "Avoid."

Blue Ocean Institute's guide offers five different color rankings, with yellow-green and orange as intermediate rankings in between the standard traffic light colors.

Food and Water Watch does not provide traffic light ratings at all. Marianne Cufone of Food and Water Watch said, "We wanted to allow people to understand the issues and make decisions based on their own values so we provided the information on each fish but we did not rank them as red, yellow, or green." However, eaters are provided with a "Dirty Dozen" list of the worst seafood choices, as well as better alternatives to each, and the guide makes clear recommendations. Uniquely, Food and Water Watch provides one guide based on flavor, helping to guide eaters to better choices based on the types of seafood they like best. Cufone says, "Our guide lists potential substitutions for popular items that may be associated with contaminants, overfishing, and other concerns. We list the fish by taste and texture, so people who know their preferences, but not the exact types of fish, are still able to consider alternatives easily."

Both Food and Water Watch and Monterey Bay Aquarium offer regional guides. Food and Water Watch's regional guides are for New England, the Gulf of Mexico, Pacific, and Mid/South Atlantic regions, each enumerating the best choices in each region. Monterey Bay Aquarium's regions are similar, but they also include the Central U.S., the Southwest and Hawaii as regions. Blue Ocean Institute does not offer regional guides; its unique offering is a sushi guide.

Another issue to a seafood eater can be lack of information. Each of the guides sometimes specifies fishing methods. For fish like mahi-mahi, Alaskan salmon, Atlantic skipjack tuna, and Pacific albacore tuna, Food and Water Watch says, "Choose pole- or troll-caught fish." If you are not buying directly from a fisherman, how will you know how your fish was caught? For that reason, Monterey Bay Aquarium wrote its guide assuming a lack of information and the worst-case scenario. "Very little canned tuna, for example, has information on the label telling consumers how it was caught," said Peterson, "We ranked canned tuna as red because it is often caught with longlines that kill endangered albatrosses and sea turtles. But major seafood buyers like food service companies are sometimes able to get more information from their suppliers, allowing them to serve sustainable canned tuna in their cafes."