WBC Nutrition Committee: Fish Facts (Part 3)
By Dr. Phillip Goglia
Swordfish contains some of the highest levels of mercury among fish, and keep in mind that mercury levels accumulate over time. The EPA recommends one serving per month for adults (assuming no other contaminated fish are consumed), and swordfish should be avoided by children completely. Additionally, most swordfish are caught using long lines, a method that also catches threatened or endangered creatures, including turtles, sharks and seabirds.
Often sold as “white tuna,” escolar is considered outrageously delicious, however eating too much of it can cause keriorrhea ─ an unpleasant form of diarrhea. Escolar contains an indigestible fatty substance called gempylotoxin, which gives the fish its lusciously buttery taste and texture, but it can cause intestinal problems if a diner overindulges. Keep this in mind when ordering or buying the fish and stick to a serving of 6 ounces or less.
Most types of tuna, including yellowfin, albacore, blackfin, bigeye and light tuna contain moderate to high levels of mercury. Bluefin tuna has elevated levels as well but it also scores poorly in eco-friendliness. Longlines are the most common method of catching and this results in high numbers of bycatch. Also, because of the high demand of bluefin tuna (mostly for sushi), the species has been greatly overfished. These fish grow to an average of 500 pounds and are slower to mature — they’re often caught before they’ve had a chance to reproduce.
RED SNAPPER (WILD, U.S. SOUTH ATLANTIC)
Red snapper makes Seafood Watch’s “Avoid” list because of a persistent overfishing issue resulting in a severe decline in the population since the 1980s. You should also exercise caution if purchasing red snapper because “true” red snapper (which ranges from Massachusetts to Mexico) is often mislabeled in the market. Other fish including tilapia and rockfishes are commonly marketed under the red snapper name. Better alternatives to red snapper include black cod and striped bass.