Dolphin-Free Tuna: Where Are We Today?

We just received a deceptively difficult question at “How can people be assured that tuna are caught in ways that don’t harm dolphins?” The simple answer is to buy tuna with the dolphin-free label which, in the U.S., you will see on cans of Starkist, Bumble Bee, and Chicken of the Sea. But, how free of dolphins is “dolphin-free”? Read on for more about this issue as we piece together a twisted history of the issue.
Tuna and dolphin have a unique relationship that scientists still don’t fully understand. The creatures tend to swim together: dolphins at the water’s surface, tuna (particularly yellowfin, marketed as “ahi”) below the surface. In the 1950s, fishermen in the Eastern Tropical Pacific—origin of much of the tuna consumed in the U.S.—began to take advantage of this natural behavior. They developed the purse seine net fishing method and relied less on individual hook-and-line or harpoon capture. (The purse seine is a net that surrounds schooling fish and then is drawn together by a rope around its lower edge into a purse.) By being on the look-out for dolphin herds, fishermen were able to find and encircle tuna. Dolphin were killed or injured in the process. The numbers of dolphins that died tended to be few because the gear was relatively small and lightweight.
Larger and heavier equipment increased the efficiency of catching tuna but dolphin mortality escalated. U.S. tuna fishermen realized that their livelihood was linked to the survival of dolphins. They began to develop less lethal gear and techniques. One such practice was named the “backdown method.” Vessels would reverse when one-half to two-thirds of the net was retrieved, pulling a section of the net underwater and allowing the dolphins to escape. Manned rafts were also introduced to help guide the dolphin’s escape. However, despite these efforts, dolphin mortality rates remained troublingly high.
Rising public concern prompted Congress to pass the Marine Mammal Protection Act (MMPA) in 1972 to reduce the dolphin kills “to levels approaching zero.” Although the MMPA greatly reduced the number of dolphins killed by U.S. vessels, it did not affect vessels registered under foreign flags. In time, the U.S. fleet dwindled while the overseas fleet mushroomed. As a result, the total number of dolphin deaths did not decline. Congress enacted various legislation attempting to redress the problem of a global tuna market. These prohibited the importation of yellowfin tuna from nations lacking regulatory programs and mortality reductions comparable to the United States. The US Departments of State and Commerce opposed these embargoes in the interests of good foreign relations and, so, did not enforce them.
The environmental nonprofit Earth Island Institute (EII) filed suit in the Federal District Court in San Francisco against the US Department of Commerce and won. In 1991, the U.S. enacted an embargo against Mexico and any other country that violated the MMPA. The government-regulated “dolphin-free” canned tuna label was instituted, promoted by EII and a coalition of non-governmental organizations.
Mexico sued in international court and won a partial decision. Rather than wrangle in court, the US and Mexico adopted a less stringent definition of “dolphin-free.” This term would no longer mandate essentially zero dolphin deaths but instead allowed a mutually acceptable mortality rate.
Despite these and other restrictions, dolpin populations failed to rebound. Commercial tuna fleets then began to set their nets *not* on dolphin but on floating debris at sea—beneath which juvenile tuna congregate—euphemistically called Fish Aggregating Devices (FAD). While dolphin mortality decreased on FADs, bycatch of juvenile tuna and species associated with debris rafts increased dramatically (e.g. sea turtles, ocean sunfish, etc.).
So, government and industry have made the ocean safer for dolphins…but “improved” fishing techniques may be harming less popular species. Therefore, the success and significance of the dolphin-free campaign and its label are still debated by various groups and countries.
Here’s another option: buy troll- or pole-caught albacore tuna which are hooked one at a time.
Question for you: Do you look for the dolphin-free label on cans of tuna that you purchase?
This blog on dolphin-free tuna is one of many to come. We don’t pretend to have all the answers but we’ll keep digging in order to provide context, accuracy, and updates on such important issues.
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2 comments so far

All this background is great. I am looking for the answer to
if I wish to buy canned tuna or fresh yellowtail tuna,
what brand can I buy?

I hope you can give me an answer or direct me to a site that you can vouch for.


June 14th, 2008 at 3:43 pm

Hi Wendy, thanks for writing to us.

All fish hold fascination with us, but tuna are unmistakably amazing animals. Their speed, range, biology, and appearance set them apart from most other fish. They also taste great.

Two separate but related considerations deserve special attention when it come to selecting which tuna to eat: means of catch and mercury burden. Choosing fish that are caught using techniques that minimize capture of other species is important. With tuna, this means trolling or pole-and-line gear–not longlines, which also hook sea turtles, seabirds, and sharks.

And although tuna don’t live very long, they are fish with big appetites. Their fast lifestyle and an elevated core temperature are fueled by eating lots of other fish. This translates to a susceptibility to accumulate toxins from all that they’ve eaten– a process termed bioaccumulation.

The bottom line:

1. For tuna steaks, albacore caught in the U.S. and British Columbia by troll or pole is preferable. Their fisheries are well-managed, bycatch is nil, and their relative mercury levels are low.

2. For canned tuna, chunk light is best. Canned tuna tends to contain skipjack, which possess lower levels of mercury and tend to be responsibly fished.

To learn more–and there’s loads more to these issues–here are a few
good sources:

Environmental Defense Fund (EDF): “Seafood Selector”

EDF: “Health Advisory”

CONSUMER REPORTS: “Mercury in Tuna”

TreeHugger: On Marine Stewardship Council (MSC) certification of a U.S.
albacore fishery

Monterey Bay Aquarium: “Seafood Watch”

Wikipedia: Tuna

Patricia Parisi
June 16th, 2008 at 10:21 am

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