The labels on tuna cans are packed with all sorts of specialized vocabulary. Some are desirable things to look for; others may not mean quite what you think. For more information on making sustainable choices, see the Monterey Bay Aquarium Seafood Watch. Here’s what you need to know when you’re shopping.
A species of tuna with the lightest-colored flesh and mildest flavor, also known as bonito del norte or “white” tuna
Yellowfin, skipjack, and bluefin
Different species of tuna with darker flesh than albacore, also known as “light” rather than “white” tuna; they tend to have more fish flavor than albacore (think dark versus white meat on chicken)
A slightly misleading term for albacore tuna, because the actual color of albacore tuna can range from cream to pink to tan
Could be yellowfin, skipjack, or bluefin, or a combination of these; the meat has a darker tan to brownish color than “white” albacore. When the label doesn’t specify which type of tuna it is, it’s probably a mix.
Tuna that is packed mostly in one layer, as a single fillet
Tuna that is in the form of chunks or flakes of varying sizes
A term (the Italian word for "tuna") permitted by the U.S. Food and Drug Administration to appear on cans referring to solid-pack tuna packed in oil
Marine Stewardship Council–certified products must meet rigorous standards for sustainable fishing practices, such as limiting bycatch (unwanted fish), avoiding overfishing, and protecting marine environments
The tuna is harvested using fishing methods that are not harmful to dolphins. This claim frequently appears on cans of tuna, but there are disputes about how meaningful it is and whether it is widely enforced
Pole and Line Caught
Tuna caught one-by-one on traditional fishing lines, each held by a person. This claim often appears on cans of tuna and it is considered one of the most sustainable methods, because it leads to no destructive bycatch of unwanted species.
Not often seen on labels (probably because “troll” doesn’t have quite the same ring to it as “pole” caught), this refers to a system whereby many baited individual fishing lines are attached to a boat and dragged slowly through the water. Similar to pole caught, but without individual fishermen holding the lines
While this looks like a good claim to make, nearly 99 percent of tuna is wild-caught; tuna farming is in its infancy and mostly focuses on bluefin tuna eaten fresh, not canned
A cylindrical net that can be closed at the bottom to trap a school of fish drawn to a spot by bait. This method is criticized for the high amount of destructive bycatch it can yield along with the intended tuna. This common method is not usually mentioned on cans, and where no other method is listed, is a likely way the fish were caught
Fish Aggregating Devices are man-made floating objects that are made to resemble floating seaweed and logs that attract fish, which are then netted. FADs are criticized by environmental groups for a high amount of destructive bycatch; sea turtles and other species that are not tuna are swept up with the tuna and killed. This method is not usually mentioned on cans, and where no other method is listed, is another likely way the fish were caught
An additive to canned tuna that helps prevent color loss and the formation of (harmless) struvite crystals during processing; albacore tuna is the species most prone to forming these crystals