How to Buy the Best Fish
Check this expert guide to nutrition, environmental issues, and selection before you head to the fish counter.
It’s easy to feel overwhelmed at the fish counter. Which is tastiest? Which is healthiest? Which is the most sustainable choice? Partly because of all the confusion, more than half of Americans seldom, if ever, eat fish, and if they do, it’s usually at a restaurant. That’s unfortunate because fish, particularly those high in a type of healthful fat called omega-3 fatty acids, can confer substantial health benefits. Moreover, fish is easy to cook at home. Here you’ll learn the essentials so you can choose the tastiest, healthiest, and most sustainable fish at the market and enjoy it at your table.
Fish accounts for 42 percent of supermarket seafood sales, with pollock (used for such items as fish sticks), canned tuna, fresh salmon, flounder, cod, tilapia, and catfish the most popular.
Top chefs often feature “day-boat” fish caught locally on restaurant menus, but unless you live near water, it can be challenging to find the freshest fish. Often the fresh fish you buy to prepare at home has been frozen. Fish sold as fresh can be anywhere from one day to two weeks out of the water. Large fishing vessels may stay at sea for two weeks, keeping their catch on ice to sell fresh. Even locally caught fish may take days traveling from boat to truck to wholesaler to retailer to your kitchen.
For top quality, look for “Frozen-at-Sea” (FAS)―fish that has been flash-frozen at extremely low temperatures in as little as three seconds onboard the ship. When thawed, sea-frozen fish are almost indistinguishable from fresh fish, according to the United Nations Food and Agriculture Organization.
The USDA requires all fish to carry a label stating if it’s wild-caught or farm-raised and identifying its country of origin.
• Line- and net-caught fish: Line-catching includes hook and lines used for recreational fishing, longlining (a main line carrying several thousand short lines), and trolling (several unconnected lines slowly dragged behind the vessel). Line-caught fish are generally higher in quality than those caught in a net.
• Farmed fish: Aquaculture―the practice of raising fish in enclosed ocean pens or freshwater ponds or tanks―has expanded dramatically in the last 30 years and now supplies about half of our seafood.
• Aquaculture: Farmed fish help ease strain on over-fished species, but when raised in open-water pens, harmful organisms can migrate from pens to wild fish. Also, carnivorous fish, like salmon, eat fishmeal produced from decreasing stocks of smaller fish. Farmed salmon is generally higher in contaminants like PCBs, a reason why many environmental organizations place it on their lists of fish not to buy. But in a study published by the Journal of the American Medical Association, scientists calculated that if 100,000 people ate farmed salmon twice a week for 70 years, the extra PCBs could potentially cause 24 extra deaths from cancer―but the salmon consumption would prevent at least 7,000 deaths from heart disease. Also, farmed salmon is widely available, high in omega-3s, and reasonably priced―all attractive qualities. And you can minimize contaminants by removing the skin and trimming any visible fat.
• Mercury: Carnivorous fish contain higher levels of mercury, which they absorb from prey. Mercury interferes with brain development in fetuses and children. The Harvard School of Public Health advises women who are or may become pregnant, nursing mothers, and children to eat two servings per week of fish and avoid the following: shark, swordfish, tilefish, and king mackerel.