The fall of King Tuna

Captive blue fin tuna inside a transport cage. The cage is being towed by a tug from fishing grounds in Libya to Tuna farms in Sicily.

Photo by Gavin Newman / Greenpeace

Far out to sea in the deep waters of the Pacific, a growing swirl of fish glistens just below the surface, advertising themselves as a tempting catch for a school of yellowfin tuna. With the help of internal body temperature regulators, the tuna crank up an extra spurt of speed, powering through the waves as fast as a galloping horse into the centre of the feast.

But the feeding frenzy quickly ends as a lethal ‘fish aggregating device’ (a floating piece of debris placed to attract feeding fish) ensnares the tuna. Open ocean species like tuna are often drawn to coconuts, logs, seaweed or other objects bobbing around in the sea. When these are topped with identifying flags or GPS units, the hunter quickly becomes the hunted.

So lured, the tuna are snared in the rapidly closing net of a Taiwanese fishing boat and swung out of the water in a suffocating, writhing mass. The prized fish conserve heat, generated by physical exertion, in their circulatory system, which helps them forage in cold water and digest food quickly. But in long struggles this can cause them to risk death from overheating – they literally cook from the inside with the warmth of their own body. Once on deck they are rapidly dispatched and stacked in freezers below.

Half a world away, in the warm waters of the Mediterranean, the tuna’s bluefin cousins are also snared. This time their fate is not sealed in a fast freezer. Instead, these highly migratory fish are caged and dragged through the water in tuna ‘ranches’, to be farmed and fattened until they are old enough for market.

Tuna are often touted as the world’s favourite fish, used in everything from cat food to high-class sashimi. The demand is endless but the supply is clearly finite. The much-publicized health benefits of a low-fat, high-protein diet have resulted in an insatiable global appetite for tuna. In the last 50 years, 90 per cent of big predatory fish like tuna have vanished – wiped out in one generation.

Overfishing is the curse of every ocean and almost all fisheries. According to the UN Food and Agriculture Organization, three-quarters of all fish stocks are in trouble, in decline, or struggling to recover from exploitation. More and bigger boats are chasing fewer, smaller fish – reaching far beyond their home ports and all too often into the waters of other countries less able to compete. The European fleet alone has a catch capacity two to three times greater than its seas and oceans can sustain. Floating factory ships can stay at sea all year round. The Annelies Ilena, newly built and launched just a few months ago, can catch a third of a million tonnes of fish a year – enough to supply double the entire yearly fish demands of Hong Kong.

And then there are the pirate fleets from countries like Thailand and China that take up to 19 per cent of the global catch. In some regions, like West Africa, this figure is substantially higher. Billions of dollars of illegally caught fish are served up on legitimate plates worldwide as pirate boats launder their catch through insufficiently monitored ports or by transferring to so-called legitimate vessels far out to sea. The high price for key species like bluefin tuna and Patagonian toothfish are white gold for the pirates. A single bluefin can fetch as much as $100,000 in Tokyo’s main fish market.

Local fishing communities have no hope of competing. Fisherfolk have little choice but to work the foreign boats in their own waters and watch as vital food is frozen for markets abroad or wasted, thrown back dead or dying as unwanted ‘by-catch’. Industrial fishing nets can be the size of a football pitch, so-called ‘long-lines’ can stretch for more than 100 kilometres, barbed with thousands of hooks. Levels of by-catch can be up to 90 per cent of the haul. Sharks, turtles and dolphins are indiscriminately snared. Other extreme fishing methods, like bottom trawling, literally tear up the ocean floor as vast nets with giant rollers wipe out entire habitats and species.

Where the wild things are no more, fish farming and ranching is becoming more prevalent as a solution to over-fishing. But the lesson of the Mediterranean tuna is testament to the flawed process, regardless of the target species.

Tuna are migratory – a round trip of 18,000 kilometres is the norm for some. In the Mediterranean the juvenile tuna are caught and penned in giant cages, swimming in endless meshed circles as they are dragged across the sea to tuna ranches for artificial fattening.

In order to feed the once-wild fish, more fish need to be caught. The irony of fish farming worldwide is the amount of fish it takes to grow a fish. Depending on the species, up to 20 kilos of wild fish may be needed to raise 1 kilo of farmed fish. Species like salmon require diets heavy with fishmeal and fish oil: it can take four and eight tonnes of wild fish to make one tonne of each respectively. The system is the epitome of ‘robbing Peter to pay Paul’.

A huge proportion of industrial fishing is for feed, not food. Intensively farmed cows, chickens and fish are all at least partly fed on fishmeal. However, the so-called ‘trash fish’ used for fishmeal are also often the staple diet for local communities. But instead of feeding families the stocks are scooped up, then ground and dumped as pellets into feeding ponds and troughs. Where farms are close to wild stocks, the farming process can also have devastating impacts on natural fish populations – spreading parasites and disease. At the same time, farming releases various toxins into the water. A wide variety of chemicals and drugs may be added to aquaculture cages and ponds in order  to control viruses, bacteria, fungi and other pathogens. The use of antibiotics also brings a potential risk to public health as over-use of these drugs can result in the development of antibiotic-resistant bacteria that cause disease in humans.

Fish farming also consumes a vast amount of space, resulting in the destruction of mangrove forests and other important coastal ecosystems. Elsewhere, coastal communities have been forced to relocate to make way for industrialized shrimp ponds.

Often farmed fish suffer from skin lesions, parasites and other diseases associated with being kept confined. Pollutants in the ocean mean that wild stocks also carry contaminants back into the food chain. Scares about mercury levels in tuna and other oily fish in northern latitudes have caused some countries to recommend that pregnant or nursing women avoid eating them altogether. Worldwide, ocean pollution is a growing problem. Plastic that does not degrade is often ingested by fish or marine animals, while oil spills and general garbage contaminate fisheries – we dump three times more rubbish into our oceans than we take out as fish.

In the Pacific, where 50 per cent of the world tuna catch is netted, a trash vortex of plastic that can stretch for thousands of kilometres endlessly circles between ocean currents.

The facts of ocean degradation are no longer in dispute. The tragedy is that the regional government bodies put in place to ‘manage’ fish stocks have comprehensively failed to do so. The proposal to have Atlantic bluefin tuna protected under the Convention on International Trade in Endangered Species is not a sign of good management – it is a desperate intervention to save a species.

Activists on an inflatable boat next to the world’s biggest tuna fishing vessel, the Albatun Tres. The ship can take 3,000 tonnes of tuna in a single trip, almost double the annual catch of some Pacific island countries.

Photo by Paul Hilton / Greenpeace

The oceans are carved up into management regions. Each regional fisheries management organization (RFMO) is made up of nations with a vested interest in the region or the stocks. The International Commission for the Conservation of Atlantic Tuna (ICCAT) has overseen a decline in tuna stocks year after year, despite annual advice from their own government scientists to reduce the catch and close spawning grounds. But the governments in ICCAT are not unusual. Almost every fish stock in every ocean is a lesson in fishing to the edge, not investing in the future.

Our oceans house more than 80 per cent of life on Earth – the UN has declared 2010 as the Year of Biodiversity. But the declaration will be hollow unless there is significant change.

The story of tuna is the story of the oceans and at the moment it makes grim reading. But we can take hope in the knowledge that the oceans are highly resilient – if we give them space. With the right protection and strong international agreements, almost all the troubled waters can be calmed. We need a global network of marine reserves covering 40 per cent of the world’s oceans, combined with international and regional agreements to ensure the remaining 60 per cent is used sustainably and fairly. 

It is possible to turn the tide on the destruction of the oceans.   But we need to start moving on it now.

Sara Holden worked as a television journalist before joining Greenpeace in 2000, where she combines journalism and activism. With parents who met while sailing, she is equally at home on the deck of one of the Greenpeace ships out in the ocean, or behind a laptop screen. Frequently she does both at the same time.

Formerly a freelance technology journalist, Greg McNevin now works in communications for Greenpeace international. He is currently focused on ending whaling in the Southern Ocean, by helping Greenpeace Japan activists Junichi Sato and Toru Suzuki fight a landmark court case after being arrested for exposing large-scale corruption in the whaling industry.