You’re probably already conscious that you have to eat fish twice a week. Fish is a safe, lean source of protein-and fatty forms such as salmon, tuna, and sardines-deliver those heart-and brain-healthy omega-3 fats that you should also get in your diet. But then there’s the worry over selecting sustainable seafood. It isn’t always simple to know what seafood is best for your health and the environment.
Luckily, the Monterey Bay Aquarium’s Seafood Watch programme has merged knowledge from leading health organisations and conservation groups to come up with “Super Green: Best of the Best,” their list of seafood that is good for you and good for the environment. Fish must: have low levels of contaminants-below 216 parts per billion [ppb] mercury and 11 ppb PCBs; be high in health-promoting omega-3 fats; and derive from sustainable fisheries to make the list, last revised in January 2010.
Many other options are on the “Best Choices” list of the programme. The Blue Ocean Institute also has ratings and comprehensive information on sustainability.
6 Most Nutritious Fish to Eat
Here are six fish that are safe for you and the world, according to Seafood Watch.
- Tuna Albacore (troll- or pole-caught, from the US or British Columbia)
Many tuna are high in mercury, but albacore tuna, the commonly canned form of white tuna, gets a Super Green ranking as long as it is “troll or pole-caught” in the US or British Columbia (and this is the clincher). The reason: smaller fish (usually less than 20 pounds) are typically captured this way by younger fish (as opposed to the larger fish caught on longlines). These fish have much lower levels of mercury and toxins and higher omega-3 counts are also found in those caught in colder northern waters. The challenge: To know how your fish was caught or look for the blue eco mark of the Marine Stewardship Council (MSC), you need to do your homework.
- The Salmon (wild-caught, Alaska)
Consider this: Biologists are posted at river mouths to count how many wild fish return to spawn, to give you an idea of how well-managed Alaska’s salmon fishery is. If the numbers continue to decline, the fishery will be closed until it hits its limits, as some Chinook fisheries have recently done. Together with tight quotas and diligent water quality control, this close monitoring ensures that Alaska’s wild-caught salmon are both healthier (packing 1,210 mg of omega-3s per 3 ounce serving and bearing few contaminants) and more sustainable than almost every other salmon fishery.
- The Oysters (farmed)
Oysters that are farmed are fine for you (a 3-ounce serving contains over 300 mg of omega-3s and about a third of the recommended daily values of iron). Better still, they are good for the environment, practically. Oysters feed off the water’s natural nutrients and algae, which increases the quality of the water. They may also act as natural reefs, attracting and supplying other fish with food. One health caveat: bacteria that can cause diseases may be present in raw shellfish, especially those from warm waters.
- Sardines, from the Pacific (wild-caught)
The small, cheap sardine, and with good reason, makes it into several superfood lists. It packs more omega-3s (1,950 mg!) than salmon, tuna, or just about any other food per 3-ounce serving; it is also one of the very, very few foods naturally rich in vitamin D. Many fish are usually called sardines in the herring family. Pacific sardines, easy to reproduce, have recovered from both overfishing and a natural collapse in the 1940s.
- Trout of the Rainbow (farmed)
While lake trout is high in toxins, almost all the trout you’ll find on the market is rainbow trout farmed. Rainbow trout are predominantly farmed in freshwater ponds and ‘raceways’ in the US, where they are more protected from pollutants and fed a fine-tuned fish meal diet to maintain energy.
- Coho Salmon Freshwater (farmed in tank systems, from the US)
The first, and only, farmed salmon to get a Super Green ranking is freshwater coho salmon. For a few reasons, all other farmed salmon also falls on the Seafood Watch ‘stop’ list of the Monterey Bay Aquarium. Many farms use crowded pens that can quickly infect salmon with parasites, treat them with antibiotics, and spread disease to wild fish (one reason Alaska has banned salmon farms). Even, raising one pound of salmon can require as many as three pounds of wild fish. However, in closed freshwater pens, coho is raised and needs less feed, so the environmental effects are minimised. They’re also a good source of omega-3s, offering 1,025 mg for one 3-ounce serving.
6 Fish for Avoidance
A variety of environmental organisations have championed the elimination of certain fish from the menu. The big fish mentioned below are only six examples of common fish that are both depleted and bear higher levels of mercury and PCBs in many instances. Health advisories were also posted by the Environmental Protection Fund (EDF) on some of these fish at edf.org.
- Tuna Bluefin
In December 2009, alongside the giant panda, tigers, and leatherback turtles, the World Wildlife Fund placed bluefin tuna on its ’10 for 2010′ list of endangered species. While protected status is favoured by environmental groups, the bluefin continues to command as much as $177,000 a fish. Bluefin has high mercury levels and its PCBs are so high that it is advised by EDF not to eat this fish at all.
- Sea Bass of Chile (aka Patagonian Toothfish)
The Chilean sea bass, slow-growing and coveted for its buttery meat, has been fished in its native cold Antarctic waters to near extinction. The techniques used to capture them have also destroyed the ocean floor and hooked albatross and other seabirds-trawlers and longlines. There is one well-managed fishery at present that is MSC-certified. Due to elevated mercury levels, EDF has issued a consumption warning for Chilean sea bass: adults should consume no more than two meals a month and children 12 and younger should eat no more than once a month.
- The Grouper
In these giant fish, high mercury levels have prompted EDF to issue a consumption advisory. Groupers can live to be 40 but multiply over a limited period of time, rendering them susceptible to overfishing.
- Among Monkfish
This strange fish is like a catfish because it has whiskers and is a bottom-dweller, but its light, fresh flavour has made it a gourmet staple. After being depleted, the fish recovers some, but the trawlers dragging for it still threaten the habitat where it lives.
- Roughy Orange
This fish, like grouper, lives a long life but is slow to reproduce, rendering it susceptible to overfishing. As Seafood Watch puts it: “Orange rough lives 100 years or more, so that a fish older than your grandmother could be the fillet in your freezer!” “This also means that it has elevated levels of mercury, prompting a health warning to be released by EDF.
- The Salmon (farmed)
Most farmed salmon (and all farmed salmon called ‘Atlantic salmon’) are raised in tightly packed, open-net pens that are often fraught with parasites and diseases that threaten wild salmon attempting to migrate through their ancestral spawning waters. Farmed salmon are fed fish meal, are given antibiotics to battle diseases and have sufficiently high levels of PCBs to rate an EDF health advice. However, recently, freshwater-farmed coho salmon has won Seafood Watch’s Best Choice status. In order to implement better practises, market pressure can encourage more farms.