Much Ado About Tuna
Tuna sandwich, tuna melt, tuna casserole, tuna and corn chowder, tuna dip, tuna and white bean salad, tuna pasta. If you’re like most ordinary consumers, chances are you have at least one can of tuna in your pantry, ready to be transformed into a quick meal such as these. But have you taken a close look at the can? If so, you’d notice the ubiquitous “dolphin-safe” label prominently featured on 98% of canned tuna sold in the United States. Even your cat is Flipper’s friend, as numerous cat foods also market themselves as dolphin-safe. Cute, intelligent, and playful, everyone loves dolphins so this is a good thing right? Well, what does dolphin-safe tuna even mean?

Purse seining, the primary method of catching tuna for canning, involves using nets a mile long and 800 feet deep. When fishermen locate a school of tuna, they release skiffs that encircle the school and then “purse” or draw the bottom of the net together, hauling the frantic fish onto the boat in a Gulliver-sized knapsack. Locating the schools is undoubtedly the most challenging aspect of tuna fishing. In the Eastern Tropical Pacific Ocean, fishermen discovered some 60 years ago that adult yellowfin tuna tend to travel below pods of dolphins. Scientists are still unsure why this phenomenon occurs, but this behavior has only been documented in the Eastern Tropical Pacific. Because dolphins need to resurface for air, pods of dolphins make for exceptional “tuna beacons” and fishermen began tracking herds of dolphins in the 1950s in search for their valuable travel buddies. Once dolphins are sighted, fishermen chase the herd and then encircle them with their stadium-sized nets. The nets are then pursed and hauled into the boat, tuna and dolphins alike. An estimated 6 million dolphins have been killed by this fishing method over the past 50 years, the largest marine mammal kill in history. By comparison, the total number of all whales killed during commercial whaling in the 20th century was around 2 million.
In 1986 the Earth Island Institute set to end this slaughter through the International Marine Mammal Project (IMMP). Through a series of consumer boycotts and PR campaigns, the Earth Island Institute eventually pressured the tuna industry to adopt “dolphin-safe” practices. In 1990, StarKist, Bumble Bee, and Chicken of the Sea, the largest tuna companies in the world, voluntarily agreed to only sell dolphin-safe tuna. To be considered dolphin-safe, fishermen cannot chase, encircle or net dolphins and ships greater than 400 tons must have an observer onboard at all times. By the mid 1990s, the dolphin-safe fever had caught on, and today canned tuna in the world’s largest tuna markets - U.S., Europe, Canada and Australia - is almost exclusively dolphin-safe. At first glance, these dolphin-safe standards seem to be quite successful – since their inception, dolphin deaths in the Eastern Pacific have fallen from 130,000 per year to around 1,000.
Unfortunately, there isn’t a fairy tale ending to the dolphin-safe story. Instead, it appears that the conservation efforts opened an entirely different can of worms (and tuna). Without their chosen method of fishing, fishermen in the Eastern Tropical Pacific began to exploit another inexplicable behavior of tuna and other pelagic fish – open-ocean animals tend to aggregate around any floating solid object. These floating objects are so effective at aggregating tuna that fishermen create their own floating objects, coined fish aggregating devices (FADs). Often crude constructions of no more than a wood frame with tentacles of mesh dangling below, FADs can aggregate up to 250 tons of fish beneath them. Using this method, fishermen deploy their sonar and GPS-equipped contraptions at sea and monitor the incoming data for location and volume of fish underneath. Once the FAD aggregates sufficient fish, fishermen move in with their nets, indiscriminately capturing any creature swimming beneath their rudimentary open-ocean resort. As a result, setting on FADs creates catastrophic by-catch, including endangered sharks and turtles, juvenile tuna and other predatory fish like mahi-mahi – but no dolphins. In fact, for every dolphin saved, the Environmental Justice Foundation calculated that close to 26,000 juvenile tuna, 27 sharks and rays, and hundreds of other fish are killed and often discarded as by-catch. As outlined in Charles Clover’s The End of the Line
, “They’re catching fish that haven’t had time to reproduce. From a disaster for dolphins, we have progressed to a whole ecosystem disaster.”
But the deeper we go into the dolphin-safe matter, the fishier it becomes. Ever wonder why most canned tuna doesn’t name the species of tuna involved and instead uses ambiguous phrases like “light” tuna? Most tuna caught with FADs are skipjack tuna, small tuna with incredibly high reproductive rates and are generally not considered exploited, at times even referred to as the cockroaches of the sea. However, the less fecund yellowfin and the threatened bigeye (especially juveniles) are also found beneath these devices, and as a result often find their way into a can of light tuna. And you thought you could only satisfy your bigeye cravings at trendy sushi restaurants.
Moreover, the extensive dolphin-safe greenwashing sends consumers a mixed message. Approximately 90% of tuna caught annually is already dolphin-safe, because the tuna-dolphin relationship only occurs in the Eastern Tropical Pacific. So tuna from the Indian Ocean, for example, is labeled as dolphin-safe, giving consumers the warm fuzzy feeling that they’re saving Flipper. However, the reality is that dolphin by-catch has never been an issue in the Indian Ocean and instead the dolphin-safe label diverts attention from the valid concerns surrounding fishing methods like setting on FADs.
So should you stop eating tuna sandwiches? Many scientists argue that shutting down the industry would only move it elsewhere, and instead the more effective agent is your pockets. Spurring change by supporting sustainably-sourced tuna proves a bit idealistic however. Pole-and-line fishing, the least-bad method, has negligible by-catch but this method is prohibitively expensive and cannot supplant more scalable methods like purse seining. Some in the industry now profess “dolphin-safe” dolphin fishing methods, whereby fishermen surround herds of dolphins but then “back down” on the nets before hauling them in, creating a funnel for the dolphins to escape. This method has proven effective in minimizing dolphin collateral damage, but the process still unsettles many environmentalists because of the stress-related risks involved to the dolphins.
Perhaps market forces have rung true that “in time the savage bull doth bear the yoke”, evidenced by Princes’s recent news that it will only purchase its tuna from sustainable sources. Princes, the largest canned tuna supplier in the UK, succumbed to advocacy campaigns and announced that by 2014 it will source tuna exclusively from pole-and-line fisheries and fleets that do not use FADs. This means that over half of the tuna sold in the world’s second largest canned tuna market will now be sustainably sourced, marking a significant step in the right direction for the tuna industry. Who knows, maybe tuna-safe tuna labels will even start popping up.
Resources:
Dolphin-safe cat food: http://www.tallahasseepetstore.com/index.php/products?page=shop.product_details&flypage=flypage_new.tpl&product_id=129&category_id=5&manufacturer_id=27
http://www.southernfriedscience.com/?p=6539
http://www.earthisland.org/dolphinSafeTuna/consumer/
http://www.allaboutwildlife.com/dolphins-whales/the-disturbing-facts-about-dolphin-safe-tuna/4298
http://www.eurocbc.org/page322.html
http://www.brighthub.com/environment/science-environmental/articles/36792.aspx
http://swfsc.noaa.gov/textblock.aspx?Division=PRD&ParentMenuId=228&id=1408
http://www.bbc.co.uk/blogs/thereporters/richardblack/2011/03/tuna_moving_to_end_of_the_pole.html










