Which Are the Healthiest and Most Sustainable Fish to Eat? Here Are Three Ways to Find Out
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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."
Food and Water Watch took a different approach to the lack of available information consumers have access to about the seafood they eat. Their guide includes a list of questions to ask, like "Where is it from?" and "How is it caught (or farmed)?" For each question, the guide tells what to look for in an answer and what answers should let you know that the fish is a bad choice. "The more people that ask questions, the clearer it will become to vendors that consumers care about the origin and the production of their seafood," said Cufone. "Personally, if a vendor is unable to tell me where a fish is from and how it was caught, I shop elsewhere."
Given the differences between the guides in structure and criteria, do they provide conflicting recommendations for seafood consumption? To compare them, let's look at the top three most popular types of seafood in America: shrimp, canned tuna and salmon.
Shrimp: All three guides say to avoid imported shrimp (both wild and farmed). Monterey Bay Aquarium's guide seems the easiest to understand, with a simple table format listing the many different kinds of shrimp available on the market and their rankings (all forms of domestic wild and farmed shrimp are rated either green or yellow). Monterey Bay Aquarium gives its green ratings to U.S. farmed freshwater prawns, wild-caught pink shrimp from Oregon; U.S. shrimp farmed in closed, inland ponds; and wild-caught spot prawns from British Columbia. Blue Ocean Institute also gives a green light for pink shrimp, but only gives U.S. farmed shrimp a yellow-green rating, noting that "U.S. farm-raised shrimp are a better alternative to imported farm-raised shrimp and to trawl-caught shrimp." They give wild-caught shrimp from the southeastern United States a yellow rating due to the habitat destruction and large amount of bycatch (fish other than the target species caught by accident and tossed overboard, dead and dying) associated with the method of fishing used. Food and Water Watch's guide was difficult to use when searching alphabetically by fish, but their downloadable card recommends "U.S. wild-caught shrimp, especially South Atlantic white, Pacific ("Oregon") pinks and Florida ("Key West" or "Tortugas") pinks; U.S.-farmed shrimp."
Canned Tuna: The guides diverge quite a bit on the canned tuna question. Most canned tuna is albacore (sold as "chunk white") or skipjack ("chunk light"), and both the Monterey Bay Aquarium and Blue Ocean Institute have specific sections for "canned tuna." If you use the Food and Water Watch guide, you'll need to know which species you are eating. Monterey Bay Aquarium gives canned tuna a red rating unless you can ascertain it was troll or pole caught. They give green ratings to troll- or pole-caught skipjack ("chunk light") from anywhere in the world and Pacific albacore from the U.S. or Canada.
Blue Ocean Institute gives canned tuna a rating derived by averaging the ratings of the many fish and fishing methods that may show up in the store as canned tuna. Overall the category rates yellow-green but within that the ratings range from yellow (any tuna that is longline caught) to green (any tuna that is pole or troll caught). One has to actually click on the albacore tuna page to see that it is "heavily fished in the north Atlantic" and that "management for Albacore Tuna is weak overall." Both Monterey Bay Aquarium and Blue Ocean Institute mention that tuna contains mercury (much more prominently for Blue Ocean Institute than Monterey Bay Aquarium).
Food and Water Watch recommends Atlantic skipjack and Pacific albacore tuna, but not Atlantic albacore tuna. They note the mercury issue first in their description of each fish and point out that skipjack has less mercury than other types of tuna. They also add that both Atlantic skipjack and Pacific albacore tuna are not usually caught with longlines ("known to threaten endangered birds and marine mammals"), whereas Atlantic albacore is. Also, Atlantic albacore populations are low due to overfishing whereas the other two types of tuna are not. The only problem with taking their advice is that both Atlantic and Pacific albacore are sold in cans labeled "chunk white."
Salmon: Here, all three guides agree. DO eat wild Alaskan salmon. DO NOT eat farmed Atlantic salmon (it's even made the cut as one of Food and Water Watch's Dirty Dozen). The text from the Food and Water Watch guide sums up the problem with farmed Atlantic salmon quite well: "Farmed salmon may contain levels of PCB contamination that pose a health risk to adults and children. It may also be contaminated with pesticides and antibiotics. Farmed salmon are usually raised in cages in open waters. These cages allow free-flow of anything from the farm into the wild, and promote transfer of diseases, especially sea lice, from caged to wild fish. Fish waste, uneaten food and chemicals like pesticides and antibiotics used to treat for diseases are released directly into the ocean. About three pounds of wild fish is used in feed to grow just one pound of farmed salmon. Further adding to these concerns, when farmed salmon escape, they may interbreed with local populations, reducing the genetic fitness of the wild stock, or, if they are non-native, they can out-compete the native fish for food and habitat."
Monterey Bay Aquarium adds that Coho salmon farmed in tank systems gets a green rating. They address wild-caught salmon from the continental U.S. by giving a yellow rating to anything caught north of Cape Falcon in Oregon and a red rating to anything caught south of there. Blue Ocean Institute gives all wild-caught salmon from California, Oregon and Washington a yellow rating. Food and Water Watch does not address non-Alaskan wild salmon.
All in all, the three guides provide similar information, although sometimes they differ in ways that might impact an eater's decision of what to eat (you might be much more likely to eat canned tuna if you use the Blue Ocean Institute guide compared to Monterey Bay Aquarium). Despite Food and Water Watch's extra criteria in rating fish (looking at human health and socio-economic impact), often their recommendations are the same as the other two guides. In the end, your choice of which guide to use may come down to which guide you find to be the most user-friendly.