The Ecologist

 

The magnificent bluefin tuna

Richard Ellis

1st October, 2003

Richard Ellis celebrates the beauty of one of nature’s most miraculous, and least appreciated creatures – the bluefin tuna.

‘To me, he seemed enormous, supremely beautiful and unattainable. He flashed purple, bronze, silver-gold. When he went under he left a surging abyss in the water, a gurgling whirlpool.’

So wrote Zane Grey (right) of one of his many attempts to land a bluefin tuna. Grey, better known as an author of popular western novels in the 1920s and 1930s, was a passionate big-game fisherman, spending most of his not inconsiderable royalties (his books sold 13 million copies) on fishing trips, boats, and gear. In Tales of Swordfish and Tuna (1927) he described his battles with giant bluefin, first in California – and then in Nova Scotia waters.

‘I was struck dumb by the bulk and beauty of that tuna.’ Grey wrote. ‘My eyes were glued to his noble proportions and his transforming colors. He was dying, and the hues of a tuna change most and are most beautiful at that time. He was shield-shaped, very full and round, and high and long. His back glowed a deep dark purple. His side gleamed like mother-of-pearl in a lustrous light. His belly shone a silver white. The little yellow rudders on his tail moved from side to side, pathetic and reproachful reminders to me of the life and spirit that was passing. If it were possible for a man to fall in love with a fish, that was what happened to me.’

And me. For more than 30 years, I have been studying and writing about the inhabitants of the oceans – from sharks, whales and dolphins, to giant squid, deep-sea fishes and even the lost citizens of Atlantis. But nothing has moved me as much as the plight of the great fish that is so ‘enormous, supremely beautiful, and unattainable’.

The fastest fish in the sea

The bluefin (thunnus thynnus) is the oceans’ nobility, described by Carl Safina as ‘half a ton of laminated muscle rocketing through the sea as fast as you drive your automobile… among the largest and most magnificent of animals’. Its body is a slick, scaleless teardrop, with slots into which it can fold down its dorsal and pectoral fins. Along the narrow tail-stock there is a series of finlets, the function of which is not clearly understood but which probably have something to do with reducing turbulence as the fish rockets through the water. The ‘drive train’ of the tuna consists of a crescent-shaped tail that is moved from side to side by powerful muscles. (Most other fishes move the after-part of their bodies, but the tuna propels itself by moving only its tail.)

As a result, the bluefin is the fastest fish in the sea – with a highest recorded speed of 70.4 kilometres an hour over a 20-second dash, and reported bursts of speed of up to 104 kmh. It is the largest of the tunas – and one of the largest of all fishes, reaching a length of 12 feet and a weight of three-quarters of a ton. (The International Game Fish Association record for a bluefin caught on rod and reel is 1,496 pounds, about the equivalent weight to three fully-grown gorillas.) In short, thunnus thynnus is the ne plus ultra of fishes; the most beautiful, the most streamlined, the most powerful of them all.

Not only does the bluefin swim incredibly fast, it also makes some of the longest migrations of any fish. Specimens tagged in the Bahamas have been recaptured in Newfoundland, Norway and even Uruguay. The northern bluefin ranges across the entire north Pacific, migrating from California to Japan and back, sometimes detouring as far south as New Guinea. The southern bluefin, thunnus maccoyii, lives only in the southern hemisphere and makes similarly large migrations. Along the way, bluefins feed on mackerel, herring, mullet, whiting, eels and squid. Nothing can outpace a tuna.

One man’s meat

Unfortunately for the bluefin, its dark red flesh is perceived by the Japanese as the most desirable of all fish products.

As the central and most esteemed component of sushi, high-quality tuna is greatly sought after. When the fish are sold off in the marketplace, hordes of buyers cluster round the dead animals – sniffing, tasting and pressing the fishes’ flesh between their fingers in a relentless hunt for the ideal fat content.  To aid this search, the tail is removed, sliced away so that a cross section of flesh is revealed to enable people to assess the structure and colour of the whole fish.

There are three kinds of tuna commonly used for sushi and sashimi – bluefin (hon maguro), southern bluefin (minami maguro) and bigeye (mebachi). The fatty part of tuna’s stomach is called 'toro' in Japanese, with ‘O-toro’ considered the most prized and expensive part of the tuna, like tenderloin of beef. There is also small part called ‘sunazuri’ within O-toro. The texture of sunazuri is marbled with thin lines of fat.

The whole procedure epitomises the Japanese concept of kata. ‘Kata,’ writes Global Sushi author Theodore C Bestor, ‘is the notion of the ideal form. It is the ideal of a flawless specimen of silver salmon, or a shipment of lobster that is perfectly matched in colour, weight and claw size. Kata also is the process that results in an ideal outcome – the fluid and precise moves of a master sushi chef as he fillets a block of bluefin, or the  way he arranges a tray of sea-urchin roe.’

When consumers believe they have found the ideal form of tuna, they are willing to pay prices to match. In 2001 a 444-pound bluefin sold for a record $173,600 at Tokyo’s main fish market.

With such a high price on their head, bluefins are being fished to extinction. Their north Atlantic breeding populations are estimated to have declined by about 90 per cent in the last 20 years. As with all fish populations, exact counts are impossible. But the rarer the bluefin becomes, the higher its price rises. And as the price rises further, so the fishermen strive ever harder to find more fish. The bluefin tuna has found itself a cruel victim of market economics.

BOX: TUNA FISHERIES AROUND THE WORLD

Carl Safina describes the devil-may-care approach to regulation of the world‘s major tuna fisheries

The western Atlantic bluefin

The western Atlantic bluefin is the most depleted  species    in the Atlantic tuna commission‘s portfolio. West        Atlantic bluefins were fished intensively in the 1960s by purse seiners targeting small fish for canneries. In the   1970s commercial targeting switched to large fish for   export to Japan.

In 1981 Iccat (the International Convention for the Conservation of Atlantic Tuna) concluded that the western Atlantic‘s bluefin tuna population was seriously depleted and that catches ‘should be reduced to as near zero as feasible‘. The commission‘s managers set a 1,160 metric ton annual quota for 1982, ostensibly for ‘scientific monitoring‘ purposes. But the next year, responding to political pressure from commercial interests, the commission more than doubled this ‘scientific‘ quota to 2,660 metric tons.

By 1990 the bluefin breeding population stood at an all-time low. Conservation groups got involved in 1991, pursuing an international ban on bluefin trade through the Convention on International Trade in Endangered Species. In 1992 the tuna commission agreed to halve its West Atlantic bluefin quota, but gave itself two years to phase the cut in.

Exploiting this interval, the US fishing industry hired lobbyists with access to top members of Congress. They influenced the US‘s National Research Council (NRC) to convene a review, which confirmed the history of depletion. But the NRC highlighted the fact that in the previous five years the bluefin population appeared to have stabilised (albeit at or near all-time lows). Industry lobbyists seized upon this finding of ‘stabilisation‘. And Iccat – led by a US commissioner who is a fishing-industry-paid lobbyist – used the ‘stabilisation‘ finding to justify rescinding the 50 per cent quota cut. After that, the commission increased the quota again to approximately where it had been from 1983-1992, when the breeding population had been roughly twice as large (but in continual decline). The spawning population now is about 10 per cent of what it was just prior to the Atlantic tuna commission‘s formation in the mid-1960s.

The eastern Atlantic bluefin

Catches in the eastern Atlantic and Mediterranean are far less controlled than in the west, exceeding 48,000 metric tons in recent years. In 1994 Iccat agreed to prohibit large longliners from operating in the Mediterranean in June and July. The longliners simply ignored the rule. Small fish are also under heavy pressure. Fish weighing less than 6.4 kilogrammes constitute 40 to 60 per cent of overall catches in the east Atlantic and Mediterranean.

In 1994 the commission recommended a 25 per cent reduction in bluefin catches in the East Atlantic and Mediterranean. But recent catches are higher than in 1994, and the eastern Atlantic bluefin population is considered severely over-fished.

Southern bluefin

Southern bluefin have been heavily exploited for nearly five decades, mainly by Japan and Australia. The catch peaked back in 1961 at 81,605 metric tons, with Japanese longlines taking almost all of it. By 1980 the catch nearly halved to 45,000 metric tons.

Australia, New Zealand, and Japan have had a quota system since 1986. The first annual quota of 38,650 metric tons was too high to avert continued decline.

In 1994 these three countries formed the Commission for the Conservation of Southern Bluefin Tuna (CCSBT). This was in part due to increasing scrutiny by environmental groups that were discussing action to ban the international trade in the bluefin.

Countries not party to the CCSBT (like Taiwan, Indonesia and Korea) also catch southern bluefin. As with most other bluefin fishing, this sector of the market is driven by Japan. So Japan could limit imports as a way of forcing other nations to abide by CCSBT conservation measures.

Unfortunately, Japan does not itself appear to support CCSBT conservation measures. In 1998 it intentionally broke its bluefin quota by more than 25 per cent, using 65 vessels fishing off Australia‘s west coast.

So in 1999 Australia and New Zealand used the UN Convention on the Law of the Sea to take Japan to court in Germany. Japan claimed that its ‘experimental‘ bluefin tuna fishing programme was ‘scientific‘ and not bound by the quota system. The two plaintiff countries claimed that increased fishing by Japan threatened ‘serious or irreversible damage to the southern bluefin tuna population‘. They succeeded in gaining a temporary injunction to halt the Japanese over-fishing.

Carl Safina is director of the Living Oceans programme at the New York-based conservation organisation the Audubon Society. His books include Songs for the Blue Ocean: along the world's coasts and beneath the seas (Henry Holt & Co, 1996).

This article first appeared in the Ecologist October 2003

 

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