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Tigers of the sea
BRIAN J. SKERRY/NGS/GETTY
Tigers of the sea Beautiful, predatory and endangered, tuna are rapidly being hunted to extinction. Graham Lawton joins the people trying to save them 44 | NewScientist | 14 November 2009
EDWARD PARKER/WWF-CANON
Pablo Cermeño (with harpoon) prepares to tag another tuna
P
ABLO CERMEÑO balances at the back of the small boat, legs braced, harpoon at the ready. Beneath him in the crystal waters his target is clearly visible: a shimmer of metallic turquoise that tacks left, right, left again as it is hauled inexorably towards the surface. The fisherman grunts and sweats as he does battle with the giant fish, reeling, pulling and reeling again. The fish breaks the surface; it is at least a metre long. Its cold black eye stares at us and its razor mouth gapes, exhausted from the fight. As it thrashes back and forth in the water Cermeño strikes, plunging the harpoon into
its back to deposit an electronic tagging device. Everybody cheers, and Cermeño kneels to cut the line. The fish sinks back into the water, pauses, then dives for freedom. With three strokes of its powerful muscular tail it has barrelled out of sight into the depths of the Mediterranean sea. I’ve just come face to face with what is quickly becoming one of the most endangered animals in the world: a Mediterranean bluefin tuna. Twenty years ago, these waters were thick with the mighty ocean-going predators, which can accelerate to up to 80 kilometres per hour in pursuit of prey. Today the population is close to collapse, pushed to the brink by remorseless overfishing. As is so often the case, nobody disputes that the stock is in serious trouble, but nobody seems able to do anything about it. That is why Cermeño, a fisheries scientist with the environmental group WWF, is tagging tuna. WWF is one of several organisations fighting a rearguard action to stop the highspeed destruction of a fishery that has been harvested for more than 3000 years. They are pressing for immediate action, including a temporary ban on fishing. But first they need scientific data to strengthen their case, and time is running out. “We estimate that the stock will collapse in 2012,” says Cermeño. Tuna are big business. The fish we just tagged weighed about 70 kilograms. Though small by bluefin standards, that torpedo of pure muscle would have fetched around $15,000 at market. And that is the root of the problem. With its dark, fatty meat, bluefin is considered the king of sushi. Prices are high: a single piece of bluefin sashimi in London’s upmarket Nobu restaurant will set you back £8. Even so, fishermen cannot keep up with demand, and the bluefin tuna is being rapidly hunted to extinction. The vast majority of legally caught Mediterranean tuna ends up in Japan, a trade worth around $7 billion a year. The black market is, if anything, even bigger. According to WWF, registered tuna boats routinely under-report catches in order to maximise profits. Matters are made even worse by pirate
boats, which are run largely by criminal gangs and often use spotter planes – an illegal method of locating fish. The scale of illegal fishing is staggering. In 2007, the official tuna catch in the Mediterranean was 23,154 tonnes. But the organisation that manages the fishery, the International Commission for the Conservation of Atlantic Tunas (ICCAT), estimates the true figure was more than twice that at close to 47,500 tonnes. That is not a sustainable amount. WWF claims that over the past 10 years, the average size of a tuna caught in the Mediterranean has almost halved, from 125 kilograms to about 65 kg – a sure sign of overfishing. At present rates of exploitation, WWF estimates bluefin will be commercially extinct within three years, meaning that the population is so small that it is no longer worth trying to catch fish.
Tough choices ICCAT accepts that stocks are facing “possible collapse in the near future”, with a breeding population around a third of what is needed to keep numbers steady, and three times as many fish being caught as the population can sustain. For several years now, ICCAT’s scientific advisers have been lobbying for the catch to be slashed to 15,000 tonnes or less. Last year they said that fishing should be temporarily banned to allow the stock to recover. Yet the commission’s decision-makers seem chronically unable to make the tough choices that even its own scientists say are needed. This year’s quota was 22,000 tonnes; next year it will be 19,950 tonnes. No wonder the bluefin is in trouble. That is why I have joined a research vessel off the coast of north-east Spain, to see the conservation efforts for myself. The boat is a former racing yacht retrofitted for tuna tagging by the fish’s most famous ally, Prince Albert II of Monaco. His charitable foundation is funding WWF’s research programme and his tiny principality is leading the international fight to save the bluefin. > 14 November 2009 | NewScientist | 45
”Next year, one of the smallest nations in the world will ask 175 CITES member states to make trade in tuna illegal” are a highly migratory species, he says. Those in the Mediterranean are northern bluefin (Thunnus thynnus), a species that ranges 8000 kilometres across the northern Atlantic, from Mexico to the Black Sea. It is divided into two sub-populations. The western one spawns in the Gulf of Mexico, while the eastern one spawns in the Mediterranean from April to June. That much we know. Their movements at other times of the year are a mystery. There is some suggestion that the Mediterranean population is split into several small, genetically isolated groups, which would make conserving them even more of a challenge. Nobody really knows, though. “The Mediterranean is a black hole for tuna,” says Cermeño. With most of the world’s Atlantic bluefin catch now originating in these waters, it is important to fill in these gaps to manage the stock sustainably. The tools of the trade are electronic tags that
EDWARD PARKER/WWF-CANON
Appropriately, we leave the port of Roses in the rosy light of dawn and head north towards Cap de Creus, a rugged peninsula jutting out where the rump of the Pyrenees spills into the sea. Today we are in search of adult tuna – fish weighing over 35 kilograms. These are big enough to be legally caught for market. To locate them, WWF works with sportsfishing companies that transport anglers who want a crack at the big game of the sea: shark, marlin, swordfish and tuna. Their boats are fitted with satellite equipment to track the currents, water temperature and the shoals of fish that their quarry feed on. That might make sports fishermen sound like cheating baddies, but they are not. Everything they catch is thrown back and the boat operators are happy to work with WWF because if the fish disappear, so does their livelihood. On the way to the fishing grounds, Cermeño explains the project. We know that bluefin
The trouble with putting electronic tags in young fish is that fishing boats have little financial incentive to send the tags back 46 | NewScientist | 14 November 2009
record the temperature, depth and light level, allowing researchers to reconstruct an individual tuna’s wanderings. There are two types. The most informative are “archival tags”, about the size and shape of a large test tube, which are surgically implanted into the bellies of juvenile tuna caught by the crew and hauled on board. The operation – carried out without anaesthetic – takes about 3 minutes, after which the fish are returned to the water. These tags record for up to seven years. To retrieve the data, however, you have to retrieve the tag. That means relying on fishing boats to find and return the tags once the tuna is caught. Anyone returning a tag receives a €300 reward, but so far nobody has returned a single one of the 21 tags implanted by WWF, and they fear nobody ever will. The problem is that with a reasonable-sized tuna fetching more than the price of a car, the reward is small fry, and with so many tuna taken illegally, many fishermen are suspicious of the tags. “They see us as the enemy,” says Cermeño. Tags are occasionally found discarded, he adds. The other kind of tags – the ones we will be using today – are called pop-ups. These are external tags that are implanted by harpoon into the tuna’s back just behind the second dorsal fin. They record for a year or so before breaking off and floating up to the surface, where they blink into life and beam their data home. These tags are much more likely to come good – Cermeño has retrieved information from four already – but their large size (they look like a microphone with a foot or so of cable attached) means they are only suitable for those increasingly scarce tuna that weigh over 50 kilograms. They also cost a fortune, around €3500 apiece, compared with €600 for an archival tag. Tuna tagging is laborious, often tedious work. During the summer season the crew spend day after day out at sea, often without firing a single tag. We are halfway into Cermeño’s second season; up to now he has tagged just 30 fish. Yesterday was one of the bad days. It was windy and overcast, so the team headed out into the open sea in search of juveniles. These feed in large schools near the surface and are best caught in choppy seas when they cannot see the boat. Despite the ideal conditions the team didn’t catch anything. Today the sea is calm and the sun is shining, so we are staying in sight of shore, where the adult tuna feed. The most likely spot, Cermeño tells me over a cup of coffee and a maritime chart, is a deep underwater trench north of Cap de Creus. It’s a known bluefin hang-out.
Out of tuna Over the past 20 years, bluefin tuna stocks have been fished to near collapse in the Mediterranean. By some estimates, stocks will be commercially extinct by 2012
60,000
BLUEFIN CATCH Mediterranean
50,000
FRANCE
Perpignan
Yield (tonnes)
After about 2 hours hugging the coastline we see a cluster of small boats bobbing on the glittering sea. These are the sports fishermen parked over what we hope will be a school of tuna. We chug a little closer, cut the engine, pull our trailing speedboat close, and wait. Half an hour later we are suddenly called into action. Cermeño’s walkie-talkie crackles into life with a call from one of the boats. He shouts something in Spanish, grabs his gear and motions us into the speedboat. Seconds later we are scudding across the sea towards one of the fishing boats. We pull up alongside and jump on board, where a burly, sweating man strapped into a swivel chair is straining like a bull over a fishing rod bent almost double. Cermeño talks to the captain in hushed tones. “They think it is a shark,” he tells me, disappointed. But then we see the telltale aquamarine shimmer. It’s a bluefin, our first tag of the day.
East Atlantic Unreported (estimate)
40,000
30,000
20,000
10,000
0
1955
Feeling lucky? In celebration, we go for a swim. I try to stop myself thinking about what might be lurking in the deep water beneath but as it turns out, I don’t have time to worry. Almost as soon as we dive in, the radio crackles once more, and we’re off again. The second tuna is smaller, probably 65 kilograms, but if anything it puts up even more of a fight. Cermeño skilfully tags it, and I ask him who taught him how to do this. “Myself,” he replies. Today is shaping up to be a good day. We have tagged two tuna in the space of an hour, the sun is out and the fish are biting. As the crew busy themselves preparing lunch we get a call from a boat about a kilometre away. We jump into the speedboat, but halfway there we get another call: it was a false alarm. There are no tuna. Our luck is changing and so is the weather. As the sky darkens and the wind starts whipping up the waves, we receive reports that a storm with 110-kilometre-perhour gusts is moving in from the north. The boat isn’t built for weather like that, so we turn tail and head for home. No more tuna today. I can’t help wondering whether this is the fate of the entire fishery. Certainly much of what I have heard and seen does not encourage optimism. Still, there are a few promising signs amid the bleakness. In July, Monaco’s government hatched a plan to save the tuna: have it listed alongside tigers, pandas and rhinos on CITES, the international treaty banning trade in endangered species. If the bid succeeds, it would become illegal to trade tuna across international borders,
1965
1975
1985
1995
2005
LOCATION OF TUNA TAGGING Llan¢a
SPAIN Figueres
CAP DE CREUS Roses
MEDITERRANEAN SEA 5 km
cutting Japan out of the scene and – hopefully – saving the tuna from oblivion. Monaco tried to get support from the European Union but failed to win over France, Italy, Spain, Greece, Cyprus and Malta. They all have large tuna fleets and bowed to industry pressure, which maintains that halting tuna fishing would only make matters worse by forcing the entire trade underground. Monaco has now decided to go it alone. Next year, one of the smallest nations in the world will ask 175 CITES member states to make trade in tuna illegal. It needs a two-thirds majority to win. Meanwhile, there are tentative signs that things are getting better in the water. Although ICCAT has not reduced quotas much, in 2007 it did set up a rebuilding plan, shortening the fishing season and increasing the size limits on fish. Its latest stock assessments, released last month, suggest that these measures are starting pay off, with numbers of small bluefin in the north-west
Mediterranean increasing. As New Scientist goes to press, ICCAT meets in Brazil to decide the future of the fishery. The option to close it down altogether is on the table. Cermeño is not optimistic. He points out that ICCAT has consistently ignored its own advisers, and he sees no reason why it will change now. CITES listings, meanwhile, usually require many attempts to succeed. “Nobody is making the right decisions,” he says. “The more time it takes, the more time it will take for the bluefin to recover.” Perhaps surprisingly, he does not want the fishery closed down for good but would rather see a return to sustainable catches. “We want the fishing to be done as it always has. This species has been exploited by many civilisations – Phoenicians, Greeks, Romans. All of them lived in harmony with this resource. But our civilisation will be the last.” ■ Graham Lawton is deputy editor of New Scientist. 14 November 2009 | NewScientist | 47
Tigers of the sea Beautiful, predatory and endangered, tuna are rapidly being hunted to extinction. Graham Lawton joins the people trying to save them 44 | NewScientist | 14 November 2009
EDWARD PARKER/WWF-CANON
Pablo Cermeño (with harpoon) prepares to tag another tuna
P
ABLO CERMEÑO balances at the back of the small boat, legs braced, harpoon at the ready. Beneath him in the crystal waters his target is clearly visible: a shimmer of metallic turquoise that tacks left, right, left again as it is hauled inexorably towards the surface. The fisherman grunts and sweats as he does battle with the giant fish, reeling, pulling and reeling again. The fish breaks the surface; it is at least a metre long. Its cold black eye stares at us and its razor mouth gapes, exhausted from the fight. As it thrashes back and forth in the water Cermeño strikes, plunging the harpoon into
its back to deposit an electronic tagging device. Everybody cheers, and Cermeño kneels to cut the line. The fish sinks back into the water, pauses, then dives for freedom. With three strokes of its powerful muscular tail it has barrelled out of sight into the depths of the Mediterranean sea. I’ve just come face to face with what is quickly becoming one of the most endangered animals in the world: a Mediterranean bluefin tuna. Twenty years ago, these waters were thick with the mighty ocean-going predators, which can accelerate to up to 80 kilometres per hour in pursuit of prey. Today the population is close to collapse, pushed to the brink by remorseless overfishing. As is so often the case, nobody disputes that the stock is in serious trouble, but nobody seems able to do anything about it. That is why Cermeño, a fisheries scientist with the environmental group WWF, is tagging tuna. WWF is one of several organisations fighting a rearguard action to stop the highspeed destruction of a fishery that has been harvested for more than 3000 years. They are pressing for immediate action, including a temporary ban on fishing. But first they need scientific data to strengthen their case, and time is running out. “We estimate that the stock will collapse in 2012,” says Cermeño. Tuna are big business. The fish we just tagged weighed about 70 kilograms. Though small by bluefin standards, that torpedo of pure muscle would have fetched around $15,000 at market. And that is the root of the problem. With its dark, fatty meat, bluefin is considered the king of sushi. Prices are high: a single piece of bluefin sashimi in London’s upmarket Nobu restaurant will set you back £8. Even so, fishermen cannot keep up with demand, and the bluefin tuna is being rapidly hunted to extinction. The vast majority of legally caught Mediterranean tuna ends up in Japan, a trade worth around $7 billion a year. The black market is, if anything, even bigger. According to WWF, registered tuna boats routinely under-report catches in order to maximise profits. Matters are made even worse by pirate
boats, which are run largely by criminal gangs and often use spotter planes – an illegal method of locating fish. The scale of illegal fishing is staggering. In 2007, the official tuna catch in the Mediterranean was 23,154 tonnes. But the organisation that manages the fishery, the International Commission for the Conservation of Atlantic Tunas (ICCAT), estimates the true figure was more than twice that at close to 47,500 tonnes. That is not a sustainable amount. WWF claims that over the past 10 years, the average size of a tuna caught in the Mediterranean has almost halved, from 125 kilograms to about 65 kg – a sure sign of overfishing. At present rates of exploitation, WWF estimates bluefin will be commercially extinct within three years, meaning that the population is so small that it is no longer worth trying to catch fish.
Tough choices ICCAT accepts that stocks are facing “possible collapse in the near future”, with a breeding population around a third of what is needed to keep numbers steady, and three times as many fish being caught as the population can sustain. For several years now, ICCAT’s scientific advisers have been lobbying for the catch to be slashed to 15,000 tonnes or less. Last year they said that fishing should be temporarily banned to allow the stock to recover. Yet the commission’s decision-makers seem chronically unable to make the tough choices that even its own scientists say are needed. This year’s quota was 22,000 tonnes; next year it will be 19,950 tonnes. No wonder the bluefin is in trouble. That is why I have joined a research vessel off the coast of north-east Spain, to see the conservation efforts for myself. The boat is a former racing yacht retrofitted for tuna tagging by the fish’s most famous ally, Prince Albert II of Monaco. His charitable foundation is funding WWF’s research programme and his tiny principality is leading the international fight to save the bluefin. > 14 November 2009 | NewScientist | 45
”Next year, one of the smallest nations in the world will ask 175 CITES member states to make trade in tuna illegal” are a highly migratory species, he says. Those in the Mediterranean are northern bluefin (Thunnus thynnus), a species that ranges 8000 kilometres across the northern Atlantic, from Mexico to the Black Sea. It is divided into two sub-populations. The western one spawns in the Gulf of Mexico, while the eastern one spawns in the Mediterranean from April to June. That much we know. Their movements at other times of the year are a mystery. There is some suggestion that the Mediterranean population is split into several small, genetically isolated groups, which would make conserving them even more of a challenge. Nobody really knows, though. “The Mediterranean is a black hole for tuna,” says Cermeño. With most of the world’s Atlantic bluefin catch now originating in these waters, it is important to fill in these gaps to manage the stock sustainably. The tools of the trade are electronic tags that
EDWARD PARKER/WWF-CANON
Appropriately, we leave the port of Roses in the rosy light of dawn and head north towards Cap de Creus, a rugged peninsula jutting out where the rump of the Pyrenees spills into the sea. Today we are in search of adult tuna – fish weighing over 35 kilograms. These are big enough to be legally caught for market. To locate them, WWF works with sportsfishing companies that transport anglers who want a crack at the big game of the sea: shark, marlin, swordfish and tuna. Their boats are fitted with satellite equipment to track the currents, water temperature and the shoals of fish that their quarry feed on. That might make sports fishermen sound like cheating baddies, but they are not. Everything they catch is thrown back and the boat operators are happy to work with WWF because if the fish disappear, so does their livelihood. On the way to the fishing grounds, Cermeño explains the project. We know that bluefin
The trouble with putting electronic tags in young fish is that fishing boats have little financial incentive to send the tags back 46 | NewScientist | 14 November 2009
record the temperature, depth and light level, allowing researchers to reconstruct an individual tuna’s wanderings. There are two types. The most informative are “archival tags”, about the size and shape of a large test tube, which are surgically implanted into the bellies of juvenile tuna caught by the crew and hauled on board. The operation – carried out without anaesthetic – takes about 3 minutes, after which the fish are returned to the water. These tags record for up to seven years. To retrieve the data, however, you have to retrieve the tag. That means relying on fishing boats to find and return the tags once the tuna is caught. Anyone returning a tag receives a €300 reward, but so far nobody has returned a single one of the 21 tags implanted by WWF, and they fear nobody ever will. The problem is that with a reasonable-sized tuna fetching more than the price of a car, the reward is small fry, and with so many tuna taken illegally, many fishermen are suspicious of the tags. “They see us as the enemy,” says Cermeño. Tags are occasionally found discarded, he adds. The other kind of tags – the ones we will be using today – are called pop-ups. These are external tags that are implanted by harpoon into the tuna’s back just behind the second dorsal fin. They record for a year or so before breaking off and floating up to the surface, where they blink into life and beam their data home. These tags are much more likely to come good – Cermeño has retrieved information from four already – but their large size (they look like a microphone with a foot or so of cable attached) means they are only suitable for those increasingly scarce tuna that weigh over 50 kilograms. They also cost a fortune, around €3500 apiece, compared with €600 for an archival tag. Tuna tagging is laborious, often tedious work. During the summer season the crew spend day after day out at sea, often without firing a single tag. We are halfway into Cermeño’s second season; up to now he has tagged just 30 fish. Yesterday was one of the bad days. It was windy and overcast, so the team headed out into the open sea in search of juveniles. These feed in large schools near the surface and are best caught in choppy seas when they cannot see the boat. Despite the ideal conditions the team didn’t catch anything. Today the sea is calm and the sun is shining, so we are staying in sight of shore, where the adult tuna feed. The most likely spot, Cermeño tells me over a cup of coffee and a maritime chart, is a deep underwater trench north of Cap de Creus. It’s a known bluefin hang-out.
Out of tuna Over the past 20 years, bluefin tuna stocks have been fished to near collapse in the Mediterranean. By some estimates, stocks will be commercially extinct by 2012
60,000
BLUEFIN CATCH Mediterranean
50,000
FRANCE
Perpignan
Yield (tonnes)
After about 2 hours hugging the coastline we see a cluster of small boats bobbing on the glittering sea. These are the sports fishermen parked over what we hope will be a school of tuna. We chug a little closer, cut the engine, pull our trailing speedboat close, and wait. Half an hour later we are suddenly called into action. Cermeño’s walkie-talkie crackles into life with a call from one of the boats. He shouts something in Spanish, grabs his gear and motions us into the speedboat. Seconds later we are scudding across the sea towards one of the fishing boats. We pull up alongside and jump on board, where a burly, sweating man strapped into a swivel chair is straining like a bull over a fishing rod bent almost double. Cermeño talks to the captain in hushed tones. “They think it is a shark,” he tells me, disappointed. But then we see the telltale aquamarine shimmer. It’s a bluefin, our first tag of the day.
East Atlantic Unreported (estimate)
40,000
30,000
20,000
10,000
0
1955
Feeling lucky? In celebration, we go for a swim. I try to stop myself thinking about what might be lurking in the deep water beneath but as it turns out, I don’t have time to worry. Almost as soon as we dive in, the radio crackles once more, and we’re off again. The second tuna is smaller, probably 65 kilograms, but if anything it puts up even more of a fight. Cermeño skilfully tags it, and I ask him who taught him how to do this. “Myself,” he replies. Today is shaping up to be a good day. We have tagged two tuna in the space of an hour, the sun is out and the fish are biting. As the crew busy themselves preparing lunch we get a call from a boat about a kilometre away. We jump into the speedboat, but halfway there we get another call: it was a false alarm. There are no tuna. Our luck is changing and so is the weather. As the sky darkens and the wind starts whipping up the waves, we receive reports that a storm with 110-kilometre-perhour gusts is moving in from the north. The boat isn’t built for weather like that, so we turn tail and head for home. No more tuna today. I can’t help wondering whether this is the fate of the entire fishery. Certainly much of what I have heard and seen does not encourage optimism. Still, there are a few promising signs amid the bleakness. In July, Monaco’s government hatched a plan to save the tuna: have it listed alongside tigers, pandas and rhinos on CITES, the international treaty banning trade in endangered species. If the bid succeeds, it would become illegal to trade tuna across international borders,
1965
1975
1985
1995
2005
LOCATION OF TUNA TAGGING Llan¢a
SPAIN Figueres
CAP DE CREUS Roses
MEDITERRANEAN SEA 5 km
cutting Japan out of the scene and – hopefully – saving the tuna from oblivion. Monaco tried to get support from the European Union but failed to win over France, Italy, Spain, Greece, Cyprus and Malta. They all have large tuna fleets and bowed to industry pressure, which maintains that halting tuna fishing would only make matters worse by forcing the entire trade underground. Monaco has now decided to go it alone. Next year, one of the smallest nations in the world will ask 175 CITES member states to make trade in tuna illegal. It needs a two-thirds majority to win. Meanwhile, there are tentative signs that things are getting better in the water. Although ICCAT has not reduced quotas much, in 2007 it did set up a rebuilding plan, shortening the fishing season and increasing the size limits on fish. Its latest stock assessments, released last month, suggest that these measures are starting pay off, with numbers of small bluefin in the north-west
Mediterranean increasing. As New Scientist goes to press, ICCAT meets in Brazil to decide the future of the fishery. The option to close it down altogether is on the table. Cermeño is not optimistic. He points out that ICCAT has consistently ignored its own advisers, and he sees no reason why it will change now. CITES listings, meanwhile, usually require many attempts to succeed. “Nobody is making the right decisions,” he says. “The more time it takes, the more time it will take for the bluefin to recover.” Perhaps surprisingly, he does not want the fishery closed down for good but would rather see a return to sustainable catches. “We want the fishing to be done as it always has. This species has been exploited by many civilisations – Phoenicians, Greeks, Romans. All of them lived in harmony with this resource. But our civilisation will be the last.” ■ Graham Lawton is deputy editor of New Scientist. 14 November 2009 | NewScientist | 47