Dolphins and Canned Tuna

Most canned tuna sold in the U.S. displays the "dolphin-safe" stamp on the label. The complex and controversial designation arose from the changing laws and regulations around the tuna fishing industry and the debate regarding its impact on dolphins.

Contents of Canned Tuna

Canned tuna does not contain dolphin meat. The only protein in cans of tuna comes from various kinds of tuna. While some fishing practices result in unintended dolphin mortality, the dolphins have never been the target or a product.

The dolphin-safe label in the U.S. includes a graphic image of a dolphin and the words "Dolphin Safe" and "U.S. Department of Commerce." The dolphin-safe label indicates the use of fishing methods intended to reduce dolphin deaths. Requiring dolphin-safe fishing practices for tuna sold in the U.S. has greatly reduced the impact of the tuna industry on dolphins. The population of dolphins associated with tuna fishing has stabilized, although they have yet to rebound to their former numbers.

Tuna Harvesting: The Danger for Dolphins

As the popularity of tuna increased in the 1950s, particularly canned tuna, commercial fishermen felt pressure to increase supplies. From experience, they learned that in eastern tropical Pacific waters, yellowfin tuna often ran with dolphins. Dolphins were easy to spot, so fishermen would target dolphins with their nets to catch schools of yellowfin swimming beneath. As a result, millions of dolphins have perished in tuna fishing nets.

The Marine Mammal Protection Act of 1972 was modified several times in the 1980s in an attempt to curb the mortality rate of dolphins. The 1990 Dolphin Protection Consumer Information Act resulted in the "dolphin-safe" labeling campaign. It received enthusiastic public approval, yet the requirements for such labeling still left loopholes for imported tuna.

Earning the dolphin-safe label requires allowing an independent observer on each fishing vessel to confirm that dolphins were not viewed, chased, encircled, killed, or seriously injured during the tuna harvest. Mexico challenged the U.S. standards as discriminatory and succeeded in getting the World Trade Organization to order the U.S. to make changes. The U.S. responded in 2016 by expanding even tougher rules for tuna caught worldwide. While previously Mexico was the only nation the U.S. required to have observers aboard, now tuna boat operators from Ecuador, Panama, and other nations also must be trained in dolphin-safe practices and may be required to have onboard observers.

U.S. consumers purchase about 50 percent of the canned tuna produced worldwide. Many international tuna companies comply with the policies set by the International Marine Mammal Project of the Earth Island Institute, on which the U.S. Dolphin Safe label is based.

The three most popular commercial canners, Star-Kist, Chicken of the Sea, and BumbleBee, have all pledged to remain "dolphin-safe" regardless of any future changes in the law. Many large grocery chains and warehouse stores selling generic canned tuna also require certification of dolphin-safe practices. You can be reassured by looking for the dolphin-safe emblem on any canned tuna you purchase.

Stabilizing Dolphin Populations

Advocacy groups continue to lobby for more studies and stricter laws to protect dolphins from net fishermen. The good news is that dolphin mortality has fallen to about 1,000 deaths per year, down from over 100,000 per year in 1986 and the 500,000 in 1980.

Despite the reduction in deaths, the populations of dolphins in the eastern tropical Pacific purse-seine fishery have stabilized but not rebounded. Many theories exist as to why this may be, including that the fishing practices still place stress on dolphins or may cause such an impact on the ecosystem that dolphins suffer. When purse-seine nets are set around schools of tuna, dolphin calves may be separated from their mothers and they may be unable to locate each other when released.

Dolphins are not the only marine animals that are killed in tuna fishing. The practices deemed dolphin-safe include using fish aggregation devices such as tethered rafts or logs. However, these fishing practices can kill sharks, sea turtles, marlins, and other kinds of fish. The amount of by-catch in using these methods can affect an entire ecosystem.

Varieties of Canned Tuna

Cans labeled "light tuna" usually contain skipjack tuna, but they may also include yellowfin, tongol, or big-eye tuna. The smaller skipjack tuna generally don't associate with dolphins, reducing the potential for collateral damage during the tuna harvest. Light tuna has the strongest taste and is the least expensive.

"White tuna" refers to albacore tuna; often cans will be labeled as albacore. This fish is larger than skipjack but smaller than yellowfin tuna. It has a milder flavor and is more expensive. It is considered to be more sustainable.