Evolution Simplified

Coral Reefs 'Will Be Gone by End of the Century'

Sunday, September 11, 2011 by the Independent/UK
They will be the first entire ecosystem to be destroyed by human activity, says top UN scientist
by Andrew Marszal

 

Coral reefs are on course to become the first ecosystem that human activity will eliminate entirely from the Earth, a leading United Nations scientist claims. He says this event will occur before the end of the present century, which means that there are children already born who will live to see a world without coral.
 
Australia's Great Barrier Reef is the planet's largest reef system and one of the seven natural wonders of the world, but it may not survive the century. The claim is made in a book published tomorrow, which says coral reef ecosystems are very likely to disappear this century in what would be "a new first for mankind – the 'extinction' of an entire ecosystem".

Its author, Professor Peter Sale, studied the Great Barrier Reef for 20 years at the University of Sydney. He currently leads a team at the United Nations University Institute for Water, Environment and Health.

The predicted decline is mainly down to climate change and ocean acidification, though local activities such as overfishing, pollution and coastal development have also harmed the reefs. The book, Our Dying Planet, published by University of California Press, contains further alarming predictions, such as the prospect that "we risk having no reefs that resemble those of today in as little as 30 or 40 more years".

"We're creating a situation where the organisms that make coral reefs are becoming so compromised by what we're doing that many of them are going to be extinct, and the others are going to be very, very rare," Professor Sale says. "Because of that, they aren't going to be able to do the construction which leads to the phenomenon we call a reef. We've wiped out a lot of species over the years. This will be the first time we've actually eliminated an entire ecosystem."

Coral reefs are important for the immense biodiversity of their ecosystems. They contain a quarter of all marine species, despite covering only 0.1 per cent of the world's oceans by area, and are more diverse even than the rainforests in terms of diversity per acre, or types of different phyla present.

Recent research into coral reefs' highly diverse and unique chemical composition has found many compounds useful to the medical industry, which could be lost if present trends persist. New means of tackling cancer developed from reef ecosystems have been announced in the past few months, including a radical new treatment for leukemia derived from a reef-dwelling sponge. Another possible application of compounds found in coral as a powerful sunblock has also been mooted.

And coral reefs are of considerable economic value to humans, both as abundant fishing resources and – often more lucratively – as tourist destinations. About 850 million people live within 100km of a reef, of which some 275 million are likely to depend on the reef ecosystems for nutrition or livelihood. Fringing reefs can also help to protect low-lying islands and coastal regions from extreme weather, absorbing waves before they reach vulnerable populations.

Carbon emissions generated by human activity, especially our heavy use of fossils fuels, are the biggest cause of the anticipated rapid decline, impacting on coral reefs in two main ways. Climate change increases ocean surface temperatures, which have already risen by 0.67C in the past century. This puts corals under enormous stress and leads to coral bleaching, where the photosynthesising algae on which the reef-building creatures depend for energy disappear. Deprived of these for even a few weeks, the corals die.

On top of this comes ocean acidification. Roughly one-third of the extra carbon dioxide we put into the atmosphere is absorbed through the ocean surface, acidifying shallower waters. A more recently recognized problem in tropical reef systems, the imbalance created makes it harder for reef organisms to retrieve the minerals needed to build their carbonaceous skeletons. "If they can't build their skeletons – or they have to put a lot more energy into building them relative to all the other things they need to do, like reproduce – it has a detrimental effect on the coral reefs," says Paul Johnston of the University of Exeter, and founder of the UK's Greenpeace Research Laboratories.

An important caveat to the book's predictions is that the corals themselves – the tiny organisms largely responsible for creating reefs – may be lucky enough to survive the destruction, if past mass extinction episodes are anything to go by. "Although corals are ancient animals and have been around for hundreds of millions of years, there have been periods of reefs, and periods where there are no reefs," explains Mark Spalding, of the US-based environmental group Nature Conservancy, and the University of Cambridge. "When climatic conditions are right they build these fantastic structures, but when they're not they wait in the wings, in little refuges, as a rather obscure invertebrate."

The gaps between periods in which reefs are present have been long even in geological terms, described in the book as "multimillion-year pauses". And reef disappearance has tended to precede wider mass extinction events, offering an ominous "canary in the environmental coal mine" for the present day, according to the author. "People have been talking about current biodiversity loss as the Holocene mass extinction, meaning that the losses of species that are occurring now are in every way equivalent to the mass extinctions of the past," Professor Sale says. "I think there is every possibility that is what we are seeing."

About 20 per cent of global coral reefs have already been lost in the past few decades. Mass bleaching events leading to widespread coral death are a relatively recent phenomenon; though scientists have been studying coral reefs in earnest since the 1950s, mass bleaching was first observed only in 1983.

Dr Spalding, who witnessed the catastrophic 1998 mass bleaching in the Indian Ocean first-hand, says: "It was a shocking wake-up call for the world of science, and a shocking wake-up for me to be actually there as we watched literally 80 to 90 per cent of all the corals die on the reefs of the Seychelles and other islands in a few weeks." That single event destroyed 16 per cent of the world's coral.

But according to the book's author: "The 1998 bleaching was spectacular because it was so extensive and so conspicuous. But there have been mass bleachings that have been global since then: 2005 was bad; 2010 was bad. The visual appearance is not nearly as severe as it was in 1998, simply because there is less coral around."

These dramatic episodes coincide with unusual weather patterns such as El Niño, but are increasing in severity and frequency due to climate change. As such, tackling global warming is the most urgent solution advocated by the book. "If we can keep CO2 concentrations below 450 parts per million we would be able to save something resembling coral reefs," Professor Sale says. "They wouldn't be the coral reefs of the 1950s or 1960s, but they would be recognizably coral reefs, and they would function as reefs." The current atmospheric carbon dioxide concentration is about 390 parts per million, but few experts believe it will remain below 500 for long.

There are signs that local conservation efforts can make a difference. Alex Rogers, professor of conservation biology at Oxford University, says: "We know for certain that corals subject to low levels of stress are much more able to recover. So if you take away pressures like overfishing of coral reefs and pollution, this has profound effects on recovery. But what we're really doing is buying time for many of these ecosystems. If climate change continues at its current rate, they will be done for eventually."

Though not all scientists agree with the precise timescales set out by the book, the crisis is clear. "When you're talking about the destruct-ion of an entire ecosystem within one human generation, there might be some small differences in the details – it is a dramatic image and a dramatic statement," Professor Rogers says. "But the overall message we agree with. People are not taking on board the sheer speed of the changes we're seeing."

Our Dying Planet (University of California Press) will be published in North America tomorrow

One in Five Plant Species Face Extinction

First ever comprehensive study of plants, from giant rainforests to common snowdrops, finds 22% of all species at risk • Third of all 'extinct' mammals species found alive
by Juliette Jowit
Wednesday, September 29, 2010 by The Guardian/UK

One in five of the world's plant species – the basis of all life on earth – are at risk of extinction, according to a landmark study published today.

At first glance, the 20% figure looks far better than the previous official estimate of almost three-quarters, but the announcement is being greeted with deep concern.

The previous estimate that 70% of plants were either critically endangered, endangered or vulnerable was based on what scientists universally acknowledged were studies heavily biased towards species already thought to be under threat.

Today the first ever comprehensive assessment of plants, from giant tropical rainforests to the rarest of delicate orchids, concludes the real figure is at least 22%. It could well be higher because hundreds of species being discovered by scientists each year are likely to be in the "at risk" category.

"We think this is a conservative estimate," said Eimear Nic Lughadha, one of the scientists at Kew Gardens in west London responsible for the project.

The plant study is also considered critical to understanding the level of threat to all the natural world's biodiversity, said Craig Hilton-Taylor of the International Union for the Conservation of Nature (IUCN), which runs the world's offical "red list" of threatened species. "Plants are the basis of life, and unless we know what's happening to plants it has many implications," said Hilton-Taylor.

The results will be presented to world leaders meeting at Nagoya in Japan in October to discuss the world's biodiversity crisis, along with new red lists for vertebrates and several groups of the planet's millions of invertebrate species.

"This is a base point," said Lughadha. "What we do from now is going to lead to the future of plants. We need to challenge the idea that plants are there to be exploited by us, we need to move to a system where we're nurturing plants much more carefully [and] actively taking steps to conserve them."

Politicians and conservation experts will also be told that by far the biggest threat to plants is human – rather than natural – causes, especially intensive agriculture, livestock grazing, logging and infrastructure development.

Caroline Spelman, the environment secretary, who will travel to Japan for the final talks, said the results were deeply troubling. She added: "Plant life is vital to our very existence, providing us with food, water, medicines, and the ability to mitigate and adapt to climate change."

Scientists randomly selected 7,000 species from across the major plant groups as a representative sample of the estimated 380,000-400,000 so far known to science. Of these, 3,000 were found to have too little information to begin making an proper assessment – a result that was expected and so built into the selection process.

The remaining 4,000 species were assessed and the level or risk based on a combination of the absolute number of plants estimated in the wild, the known decline, and the total area in which they are thought to live.

Of the 4,000, 63% were found to be of "least concern", 10% near threatened, 11% vulnerable, 7% endangered and 4% critically endangered. Another 5% were rated "data deficient".

The proportion of plant species deemed at-risk is similar to that of the IUCN's red list for mammals, worse than that for birds (less than 10% at-risk) and better than the number for amphibians (more than a quarter under threat).

Nearly two-thirds of threatened plant species are found in tropical rainforests, five times the proportion for the nearest other habitats – rocky areas, temperate forests and tropical dry forests. This is because of their huge density of biodiversity and the widespread risks of logging and clearance for other agriculture, said analysts.

Previously the red list for plants contained assessments for a greater number of plants – about 12,873 or 3% of known species – but was not considered representative because scientists had focused on at-risk species so that they could get attention and funding for conservation.

The assessment was done using experts and collections at the herbaria at Kew Gardens, the Natural History Museum in London and Missouri Botanical Garden in the US, plus specialist experts from the IUCN.
From pines to snowdrops to rosewood – six of the endangered plants

Wollemi pine (Wollemia nobilis) – critically endangered

The wollemi pine was discovered in 1994 in Wollemi National Park, Australia, and there fewer than 50 mature individuals are known. Its long-term regeneration from seed is unknown but seems doubtful due to competition with other trees. Its small size and limited range means it is at risk from any chance event such as fire or the spread of disease.

Common snowdrop (Galanthus nivalis) – near threatened

The common snowdrop was once widely distributed in the east Carpathian mountains in central and eastern Europe. Although it is widely naturalised, including in the UK, during the past decade its native distribution has been considerably reduced, due mainly to habitat loss through the increase in residential developments and recreational land use.

Rosewood (Dalbergia andapensis) – critically endangered

D. andapensis is a species of rosewood, a highly valued timber sed in the production of fine furniture and musical instruments. It is estimated that 52,000 tonnes of rosewood and ebony were logged in north-east Madagascar in 2009, and this habitat is itself under threat from conversion to agriculture for a growing rural population.

Wood bitter-vetch (Vicia orobus) – least concern

Wood bitter-vetch is a rare species found through much of western Europe, including the British Isles, at woodland margins, field edges and rocky places, often on limestone. In Ireland it is considered to be threatened as a result of habitat loss, and is being protected by the National Botanic Gardens of Ireland.

Whited's milkvetch (Astragalus sinuatus) - Critically Endangered

Whited's milkvetch is restricted to a tiny area of the state of Washington, USA. Its dry hillside habitat is threatened by invasive, non-native species, by grazing and by agriculture. Seeds have been collected and banked by the Berry Botanic Garden Seed Bank for Rare and Endangered Plants of the Pacific Northwest and the Miller Seed Vault, University of Washington Botanic Gardens.

Encephalartos altensteinii – vulnerable

E. altensteinii is found in coastal regions of the eastern cape, South Africa, where the number of individuals has declined by more than 30% in the past 50 years. Large numbers have been removed from its native habitat, including 438 plants in one poaching incident in 1995, mainly by horticultural collectors for pot plants or medicinal use.

Double meteorite strike 'caused dinosaur extinction'

Double trouble for dinosaurs: Did more than one meteorite strike cause their demise?
By Howard Falcon-Lang | Aug. 27, 2010 | Science reporter, BBC News

The dinosaurs were wiped out 65 million years ago by at least two meteorite impacts, rather than a single strike, a new study suggests.

Previously, scientists had identified a huge impact crater in the Gulf of Mexico as the event that spelled doom for the dinosaurs.

Now evidence for a second impact in Ukraine has been uncovered.

This raises the possibility that the Earth may have been bombarded by a whole shower of meteorites.

The new findings are published in the journal Geology by a team lead by Professor David Jolley of Aberdeen University.

When first proposed in 1980, the idea that a meteorite impact had killed the dinosaurs proved hugely controversial. Later, the discovery of the Chicxulub Crater in the Gulf of Mexico, US, was hailed as "the smoking gun" that confirmed the theory.

Double trouble

The discovery of a second impact crater suggests that the dinosaurs were driven to extinction by a "double whammy" rather than a single strike.

The Boltysh Crater in Ukraine was first reported in 2002. However, until now it was uncertain exactly how the timing of this event related to the Chicxulub impact.

In the current study, scientists examined the "pollen and spores" of fossil plants in the layers of mud that infilled the crater. They found that immediately after the impact, ferns quickly colonised the devastated landscape.

Ferns have an amazing ability to bounce back after catastrophe. Layers full of fern spores - dubbed "fern spikes" - are considered to be a good "markers" of past impact events.

However, there was an unexpected discovery in store for the scientists.

They located a second "fern spike" in a layer one metre above the first, suggesting another later impact event.

Professor Simon Kelley of the Open University, who was co-author on the study, said: "We interpret this second layer as the aftermath of the Chicxulub impact."

This shows that the Boltysh and Chicxulub impacts did not happen at exactly the same time. They struck several thousand years apart, the length of time between the two "fern spikes".

Uncertain cause

Professor Kelley continued: "It is quite possible that in the future we will find evidence for more impact events."

Rather than being wiped out by a single hit, the researchers think that dinosaurs may have fallen victim to a meteorite shower raining down over thousands of years.

What might have caused this bombardment is highly uncertain.

Professor Monica Grady, a meteorite expert at the Open University who was not involved in the current study, said: "One possibility might be the collison of Near Earth Objects."

Recently, Nasa launched a program dubbed "Spaceguard". It aims to monitor such Near Earth Objects as an early warning system of possible future collisons.

Tuna’s End

(Where do tuna spawn/originate from? Why, the Gulf of Mexico, of course.--jef)

***

Tuna’s End
By PAUL GREENBERG

In the international waters south of Malta, the Greenpeace vessels Rainbow Warrior and Arctic Sunrise deployed eight inflatable Zodiacs and skiffs into the azure surface of the Mediterranean. Protesters aboard donned helmets and took up DayGlo flags and plywood shields. With the organization’s observation helicopter hovering above, the pilots of the tiny boats hit their throttles, hurtling the fleet forward to stop what they viewed as an egregious environmental crime. It was a high-octane updating of a familiar tableau, one that anyone who has followed Greenpeace’s Save the Whales adventures of the last 35 years would have recognized. But in the waters off Malta there was not a whale to be seen.

What was in the water that day was a congregation of Atlantic bluefin tuna, a fish that when prepared as sushi is one of the most valuable forms of seafood in the world. It’s also a fish that regularly journeys between America and Europe and whose two populations, or “stocks,” have both been catastrophically overexploited. The BP oil spill in the Gulf of Mexico, one of only two known Atlantic bluefin spawning grounds, has only intensified the crisis. By some estimates, there may be only 9,000 of the most ecologically vital megabreeders left in the fish’s North American stock, enough for the entire population of New York to have a final bite (or two) of high-grade otoro sushi. The Mediterranean stock of bluefin, historically a larger population than the North American one, has declined drastically as well. Indeed, most Mediterranean bluefin fishing consists of netting or “seining” young wild fish for “outgrowing” on tuna “ranches.” Which was why the Greenpeace craft had just deployed off Malta: a French fishing boat was about to legally catch an entire school of tuna, many of them undoubtedly juveniles.

Oliver Knowles, a 34-year-old Briton who was coordinating the intervention, had told me a few days earlier via telephone what the strategy was going to be. “These fishing operations consist of a huge purse-seining vessel and a small skiff that’s quite fast,” Knowles said. A “purse seine” is a type of net used by industrial fishing fleets, called this because of the way it draws closed around a school of fish in the manner of an old-fashioned purse cinching up around a pile of coins. “The skiff takes one end of the net around the tuna and sort of closes the circle on them,” Knowles explained. “That’s the key intervention point. That’s where we have the strong moral mandate.”

But as the Zodiacs approached the French tuna-fishing boat Jean-Marie Christian VI, confusion engulfed the scene. As anticipated, the French seiner launched its skiffs and started to draw a net closed around the tuna school. Upon seeing the Greenpeace Zodiacs zooming in, the captain of the Jean-Marie Christian VI issued a call. “Mayday!” he shouted over the radio. “Pirate attack!” Other tuna boats responded to the alert and arrived to help. The Greenpeace activists identified themselves over the VHF, announcing they were staging a “peaceful action.”

Aboard one Zodiac, Frank Hewetson, a 20-year Greenpeace veteran who in his salad days as a protester scaled the first BP deepwater oil rigs off Scotland, tried to direct his pilot toward the net so that he could throw a daisy chain of sandbags over its floating edge and allow the bluefin to escape. But before Hewetson could deploy his gear, a French fishing skiff rammed his Zodiac. A moment later Hewetson was dragged by the leg toward the bow. “At first I thought I’d been lassoed,” Hewetson later told me from his hospital bed in London. “But then I looked down. ” A fisherman trying to puncture the Zodiac had swung a three-pronged grappling hook attached to a rope into the boat and snagged Hewetson clean through his leg between the bone and the calf muscle. (Using the old language of whale protests, Greenpeace would later report to Agence France-Presse that Hewetson had been “harpooned.”)

“Ma jambe! Ma jambe!” Hewetson cried out in French, trying to signal to the fisherman to slack off on the rope. The fisherman, according to Hewetson, first loosened it and then reconsidered and pulled it tight again. Eventually Hewetson was able to get enough give in the rope to yank the hook free. Elsewhere, fishermen armed with gaffs and sticks sank another Zodiac and, according to Greenpeace’s Knowles, fired a flare at the observation helicopter. At a certain point, the protesters made the decision to break off the engagement. “We have currently pulled back from the seining fleet,” Knowles e-mailed me shortly afterward, “to regroup and develop next steps.” Bertrand Wendling, the executive director of the tuna-fishing cooperative of which the Jean-Marie Christian VI was a part, called the Greenpeace protest “without doubt an act of provocation” in which “valuable work tools” were damaged.

But the main damage that took place that day was indisputably to the bluefin. After the encounter, the fishermen aboard the Jean-Marie Christian VI transferred the fish alive into a holding cage and slowly towed them away. Soon those tuna would be brought to feeding pens where they will spend at least several months putting on weight. Afterward, they will be slaughtered and sent to Japan, where 80 percent of the world’s Atlantic bluefin tuna are eaten with oblivion.

THERE ARE TWO reasons that a mere fish should have inspired such a high-strung confrontation reminiscent of Greenpeace’s early days as a defender of whales. The first stems from fish enthusiasts who have for many years recognized the particular qualities of bluefin tuna — qualities that were they land-based creatures would establish them indisputably as “wildlife” and not just another “seafood” we eat without remorse. Not only is the bluefin’s dense, distinctly beefy musculature supremely appropriate for traversing the ocean’s breadth, but the animal also has attributes that make its evolutionary appearance seem almost deus ex machina, or rather machina ex deo — a machine from God. How else could a fish develop a sextantlike “pineal window” in the top of its head that scientists say enables it to navigate over thousands of miles? How else could a fish develop a propulsion system whereby a whip-thin crescent tail vibrates at fantastic speeds, shooting the bluefin forward at speeds that can reach 40 miles an hour? And how else would a fish appear within a mostly coldblooded phylum that can use its metabolic heat to raise its body temperature far above that of the surrounding water, allowing it to traverse the frigid seas of the subarctic?

Yes, bluefin tuna are warmblooded.

That bluefin can be huge — 10 feet and more than a thousand pounds — is a side note. For those of us who have seen their football silhouettes arise and vanish in less than a blink of an eye or held them alive, their hard-shell skins barely containing the surging muscle tissue within, they are something bigger than the space they occupy. All fish change color when they die. But with tuna the death shift feels more profound. Fresh from the water, their backs pulsing neon blue, their bellies gleaming silver-pink iridescence, they seem like the ocean itself.

And in a way they are, which explains the second reason bluefin have come to possess such totemic power. For bluefin tuna and all species of tuna are the living representation of the very limits of the ocean. Their global decline is a warning that we just might destroy our last wild food.

In prehistoric times, the hunting of fish began close by, in freshwater rivers and lakes and coastal ocean waters. But as human populations grew, easily accessed grounds fell short of demand. By the late Middle Ages, European stocks of freshwater fish and near-shore ocean species proved insufficient. By then, Basque and Viking fisherman had already moved on to the continental shelves off Canada, ushering in the Age of Cod — an age that escalated until the late 20th century, when some of the largest fishing vessels ever built devastated the once-two-billion-strong stock of cod on the Canadian Grand Banks. But there were still new places to fish. In the 1980s and ’90s, virgin fishing grounds were found in the Southern Hemisphere, and supplies of replacement fish like New Zealand hoki and Chilean sea bass helped seafood supplies keep pace with demand.

But appetites continued to outstrip supply. Global seafood consumption has increased consistently to the point where we now remove more wild fish and shellfish from the oceans every year than the weight of the human population of China. This latest surge has taken us past the Age of Cod and landed us squarely in the Age of Tuna. Fishing has expanded over the continental shelves into the international no-man’s territory known as the high seas — the ocean territory that begins outside of national “exclusive economic zones,” or E.E.Z.’s, usually 200 nautical miles out from a country’s coast, and continues until it hits the E.E.Z. of another country. The high seas are owned by no one and governed by largely feeble multinational agreements. According to the Sea Around Us project of the University of British Columbia’s Fisheries Center, catches from the high seas have risen by 700 percent in the last half-century, and much of that increase is tuna. Moreover, because tuna cross so many boundaries, even when tuna do leave the high seas and tarry in any one nation’s territorial waters (as Atlantic bluefin usually do), they remain under the foggy international jurisdiction of poorly enforced tuna treaties.

The essentially ownerless nature of tuna has led to the last great wild-fish gold rush the world may ever see. The most noticeable result of this has been the decline of the giant Atlantic bluefin tuna. But the Atlantic bluefin is just a symptom of a metastasizing tuna disease. The United Nations’ Food and Agriculture Organization reports that 7 of the 23 commercially fished tuna stocksare overfished or depleted. An additional nine stocks are also threatened. The Pew Environment Group’s tuna campaign asserts that “the boats seeking these tuna are responsible for more hooks and nets in the water than any other fishery.”

Tuna then are both a real thing and a metaphor. Literally they are one of the last big public supplies of wild fish left in the world. Metaphorically they are the terminus of an idea: that the ocean is an endless resource where new fish can always be found. In the years to come we can treat tuna as a mile marker to zoom past on our way toward annihilating the wild ocean or as a stop sign that compels us to turn back and radically reconsider.

“WE FIND OURSELVES in a precarious situation.” So wrote Ritchie Notar, a co-owner of the internationally acclaimed Nobu restaurant chain, to Greenpeace U.K. back in 2008 after Greenpeace intensified its tuna-defense efforts and put forward the idea that bluefin should no longer be served at Nobu’s establishments. “We are dealing with thousands of years of cultural customs,” Notar continued in correspondence Greenpeace forwarded to me. “The Japanese have relied on tuna and the bounties of the sea as part of their culture and history for centuries. We are absolutely appreciative of your goals and efforts within your cause, but it goes far beyond just saying that we can just take what has now all of a sudden been declared an ‘endangered’ species off the menu. It has to do with custom, heritage and behavior.”

Many nations have contributed to the Atlantic bluefin’s destruction. Europeans and North Africans do most of the catching and ranching of the fish in the world today. The United States continues to allow bluefin fishing in its waters even though the Gulf of Mexico-spawned stock is considered by many scientists to have entered into full-scale collapse. But it is Japan, the world’s largest bluefin importer, that has taken perhaps the most aggressive pro-tuna-fishing position, sometimes assisted by Westerners like Ritchie Notar, who declaim the country’s long tuna-eating tradition. But history shows that Japan’s stake in tuna fishing is recent and, more important, part of the same endgame that has dragged all of humanity into the Age of Tuna. Before 1800, Japanese tuna sushi didn’t even exist.

Trevor Corson is an East Asia scholar turned popular nonfiction writer and author of the 2007 book “The Story of Sushi,” and for select groups he will act as a “sushi concierge,” hosting dinners often at the Jewel Bako Japanese restaurant in Manhattan’s East Village, one of which I attended this past winter. A Corson-guided meal aims to reveal the historical truth of tuna and to represent the very different fish that were the staples of sushi in earlier times. Plate by plate I watched as Corson walked a group of Manhattan professionals through a traditional Edo-period meal of snappers, jacks and other white-fleshed, smaller fish that most definitely did not include “red” tuna. Afterward, Corson sent me an excerpt from a 1999 Japanese anthology titled “Fish Experts Teach the Secrets of the Deliciousness of Fish” to further underline his point. “Originally, fish with red flesh were looked down on in Japan as a low-class food, and white fish were much preferred,” one of the book’s contributors, Michiyo Murata, writes. “Fish with red flesh tended to spoil quickly and develop a noticeable stench, so in the days before refrigeration the Japanese aristocracy despised them, and this attitude was adopted by the citizens of Edo [old Tokyo].” Other Japanese scholars like the sushi historian Masuo Yoshino confirm this. Murata, meanwhile, goes on to note that tuna were introduced into sushi only 170 years ago, when a large catch came into Edo one season. On that day a local sushi chef marinated a few pieces of tuna in soy sauce and served it as “nigiri sushi.” The practice caught on. Occasionally a big bluefin became sushi, but Corson notes these fish were nicknamed shibi — “four days” — because chefs would bury them for four days to mellow their bloody taste.

By the 1930s, tuna sushi was commonplace in Japan, but demand could be met by local supplies of tuna, including the Pacific bluefin species, which dwells in Japan’s coastal waters. It was World War II that took tuna fishing to the next level. “To recover from the devastation of the war,” Ziro Suzuki, formerly of the Japanese Far Seas Research Laboratory, wrote me, “Japanese fishermen needed more tunas to secure food for domestic demand and also to earn more money by exporting tunas for canning industries in Europe and the U.S. Those needs urged the expansion of fishing grounds outside of the historic grounds of the western Pacific.” But this next fishing expansion was technological as well as territorial. Throughout the postwar period, the Japanese perfected industrial long-lining, a practice that employs thousands of baited hooks. In the 1970s Japanese manufacturers developed lightweight, high-strength polymers that were in turn spun into extensive drift nets that could be many miles long. Though drift nets were banned in the high seas by the early ’90s, in the 1970s hundreds of miles of them were often deployed in a single night. When drift nets and long lines were coupled with at-sea freezing technology invented around the same time, Japanese fishermen were able to fish the farthest reaches of the oceans while keeping their frozen tuna sushi-ready for as long as a year.

A major yield of all of this Japanese fishing effort was yellowfin tuna. Though they ate bluefin, Japanese did not hold them in high regard before the 1960s, and it took a confluence of socioeconomic factors in both Japan and the West to bring bluefin to the fore. By the late 1960s, sportfishing for giant bluefin tuna was starting in earnest off Nova Scotia, New England and Long Island. Like the Japanese at the time, North Americans had little regard for bluefin on the plate, usually discarding them after capture.

Bluefin sportfishing’s rise, however, coincided with Japan’s export boom. In the 1960s and ’70s, Japanese planes stuffed with electronics unloaded in the U.S. and returned empty — a huge waste of fuel. But when a Japanese entrepreneur realized he could buy New England and Canadian bluefin for a song, he started filling up all those empty cargo holds with tuna. Exposure to beef and other fatty meats during the U.S. occupation had already drawn the Japanese to appreciate bluefin’s fatty belly (otoro, in sushi terms). The Atlantic bluefin, the biggest bluefin, became the most favored of all. This appreciation boomeranged stateside when Americans started to develop their own raw-fish habit in the late 1970s.

Added to the already significant fishing pressure from the tuna canning industry, Japan’s and now the West’s sushi jones has come to stress populations of large tuna around the world, starting with the most environmentally sensitive Atlantic bluefin but with the risk of spreading to other species. In fact, one subpopulation of Atlantic bluefin has already vanished after heavy fishing by Japanese long-liners: The bluefin that used to congregate off Brazil disappeared in the early bluefin boom of the 1970s. The remaining Atlantic bluefin stocks are trending similarly, and the two other species of bluefin — the Pacific, which ranges between California and Japan, and the southern bluefin, which plies the waters around Australia — are not far behind. In the United States, the direct fishing pressure on bluefin continues — but perhaps a larger problem is that a large quantity of North American bluefin are caught accidentally as “by-catch” when industrial long-liners deploy their legions of hooks in search of yellowfin tuna over the bluefin’s spawning grounds in the Gulf of Mexico. By law, nearly all bluefin caught as by-catch must be dumped back into the sea. Usually by that point they are already dead.

All of this has led the bluefin to become a cause célèbre among conservation groups and the target of several organized “save the bluefin” campaigns. None of them have influenced Japanese consumers. In the case of Nobu, after numerous exchanges with Greenpeace, the sushi restaurant’s owners remained unpersuaded of the need to stop serving the fish. Their only concession was a haiku-esque warning on the menus of its London eateries:

“Bluefin tuna

Is an environmentally threatened species

Please ask your server for an alternative.”

Willie Mackenzie of Greenpeace U.K. responded angrily in a note to Ritchie Notar: “Despite the assurances that you take these issues seriously and that you want Nobu to be a leader in this field, you have essentially tried to abdicate responsibility by suggesting that it is down to your customers to decide if they want to eat an endangered species.”

AWAY FROM RESTAURANT menus and the entree preferences of individual consumers, more far-ranging choices are presenting themselves to humanity than picking a California roll or a sliver of otoro. These are choices that will shape the fate of not just Atlantic bluefin tuna, not just all tunas, but all the great sea creatures — sharks, swordfish, marlin, even whales. For every one of these animals is highly migratory and roams the high seas, the vast, ownerless seascape that makes up some 60 percent of the oceans.

Until the 1970s, fishing in the high seas tended to be based on the principles of Hugo Grotius’s 1609 treatise “Mare Liberum” — a document that advocated free use of the oceans by all. But in the last 40 years, Grotius’s “free sea” has grown progressively more circumscribed. Today, high-seas and highly migratory fish are overseen by 18 regional fisheries-management organizations. These “consensus-oriented” institutions, in which each member nation has equal status, can be guided more by political horse-trading than by sound science. A former chairman of the scientific committee of the International Commission for the Conservation of Atlantic Tunas (or Iccat), the body responsible for Atlantic bluefin, told me, “Even though scientific advice says you should stick to a specific catch number, in order to negotiate a deal they tend to nudge that number over a little bit.” That little nudge can be enough to put a population of tuna in jeopardy.

In 2008 Iccat set Atlantic bluefin catch limits that were nearly double what its own scientists recommended. Conservationists howled, and the quotas were reduced sharply. But by the time Iccat met again, in November 2009, environmentalists had come to home in on the historic mismanagement of Atlantic bluefin, many of them arguing that a simple reduction in catch quotas for the coming fishing season was not enough — that in fact a zero-catch quota was the only thing that would stave off the fish’s extinction. Iccat rejected the zero-quota idea. This in turn forced a much more high-pitched confrontation this spring between parties like Japan, which seems to feel that fishery-management problems can be resolved within the status quo, and those who are looking to take the high seas in a profoundly different direction.

The debate was joined when delegates gathered this past March in Doha, Qatar, for a meeting of the United Nations Convention on the International Trade in Endangered Species of Flora and Fauna, or Cites (pronounced SY-tees). It was a meeting that, for fish, could have been as important as the 1982 meeting of the International Whaling Commission that voted to establish a moratorium on commercial whaling worldwide. For if conservationists got their way, Atlantic bluefin would be included in the Cites treaty’s Appendix One — a result that would ban the international trade of the tuna and put them under the jurisdiction of the same U.N. body that oversees tigers, white rhinos and giant pandas. It would be the beginning of a process that would transition Atlantic bluefin tuna from seafood to wildlife.

It is precisely this kind of recasting that happened with whales in the 1980s, and Japan was intent on avoiding a similar recategorization with Atlantic bluefin tuna. As Masanori Miyahara, the director of the Fisheries Agency of Japan, put it to me: “Cites Appendix One is too inflexible . . . once a species is listed in a Cites appendix, it will never be delisted or down-listed as the history of Cites clearly shows.” In other words, once a fish becomes wildlife, it will stay wildlife. A Cites treaty would also allow those countries that happen to have bluefin in their territorial waters to continue to catch them for their own market while excluding all the other treaty member nations — a result that Masanori would surely find not only unfair but also capable of leading to further overfishing. (The European Union has indicated it will continue to catch its allowable quota even if a Cites resolution is passed.)

Japan’s touchiness about fairness on the high seas is understandable given its dependence on seafood. Its per capita seafood consumption is among the highest of any industrialized country. And Japan has not been blind to the problems that come with overfishing and excessively large fishing fleets. Indeed, in the last few years it has tried to rein in its industrial fishing effort, decommissioning vessels, literally pulling hooks out of the water. But this has failed to resolve another problem of the Age of Tuna. Just as the industrialized countries are starting to realize the need for more sensible management of the high seas, developing countries are heading in the opposite direction. “Developing countries firmly believe they have a right to expand their fisheries and that developed countries should reduce their fishing effort to compensate,” Ziro Suzuki wrote me. “In the process of trying to resolve the conflict of interest, the stocks become overfished, and overall fishing effort grows to an unacceptable level. . . . It’s really just another example of the North-South problem, just like CO2 emissions.”

The conflict between the developing and developed world plays an increasingly greater role in tuna negotiations, and at a certain point it is hard to figure out who is manipulating whom in an intrigue involving 175 countries, each trying to game the system. Representatives from both the WWF and the Pew Environment Group told me of a curious imbroglio as the Qatar Cites meeting neared its vote on bluefin. Japanese delegation members supposedly told African representatives that European bluefin fleets would relocate to the coast of Africa and catch African yellowfin tuna if the Cites bluefin motion passed. This despite the fact that European vessels are geared up specifically for bluefin fishing and lack the capacity to pursue yellowfin. Masanori Miyahara of the Fisheries Agency of Japan dismissed this claim as “completely wrong and unfounded. We never told such a thing to anybody. We even haven’t thought such an idea, ever.”

True or not, African nations lined up with Japan. After Libya and Sudan forced a vote, the Atlantic bluefin’s Cites Appendix One listing was rejected by a large majority.

Delegates flew away from Qatar with the status quo in place. The monthlong bluefin purse-seining season set earlier by Iccat for the Mediterranean would stand as it was with quotas above what many scientists had recommended. A month after the Cites meeting, BP’s Horizon Deepwater oil rig collapsed into the sea and spewed oil into the only bluefin spawning ground in the Americas just as the few remaining North American stock giant bluefin were preparing to mate in the Gulf of Mexico. Though the U.S. National Marine Fisheries Service has been deeply critical of the Mediterranean bluefin catch — in 2007, it went so far as to call for a moratorium — it has been noncommittal about the American fishery. When I asked the Fisheries Service if it would consider closing the bluefin season on the heels of the BP spill, I was offered a statement, part of which, recast in verse form, has an almost Nobu-type haiku quality:

“N.O.A.A. Fisheries is carefully monitoring

The spawning of bluefin tuna in the Gulf of Mexico

By collecting larval samples and analyzing reports from scientific observers.”

It seems then that no single nation is ready to commit to a sustainable future for the fish. Some would argue that extirpation might just have to be the bluefin’s fate. Other, smaller tuna might be better suited to industrial exploitation. The bigeye and yellowfin tuna generally grow faster and spawn earlier. And indeed these lesser tuna are already starting to fill in for the bluefin’s absence. In the United States most Americans usuallyend up eating bigeye when they order otoro — the fatty zebra-striped flesh that fetches the highest price on most sushi menus nowadays. But major populations of bigeye tuna are also declining. Should they go away, it’s hard to say what would come next.

we get ourselves out of the Age of Tuna with our moral center and our food supply intact? Can we develop a civilized hunter-gatherer relationship with tuna and indeed with all other fish and reach a point of equilibrium with our last wild food? Can the management bodies that have overseen the collapse of the most magnificent food fish we’ve ever known be trusted to manage what is left in its wake?

The answer depends on where you fall on the fairly broad political spectrum of the world’s different tuna watchers. The Fisheries Agency of Japan maintains that “Japan is committed to ensure the recovery” of the Atlantic bluefin and has stipulated it will support a complete shutdown of the bluefin fishery at next fall’s Iccat meeting, should the scientific committee recommend it. Greenpeace meanwhile has punted on the bluefin political process. “Others have failed our oceans,” Oliver Knowles told the press as he prepared his mini armada off Malta, “so Greenpeace will act.” Greenpeace is calling for a radical realignment of the high seas, to take stewardship away from regional fisheries-management organizations and establish 40 percent of the world’s ocean territory as a marine reserve, a kind of Antarctica-style agreement with shades of whale, where nations, instead of bargaining over quotas, would simply not be able to do any fishing at all in large areas of the oceans. Most other environmental organizations are behind the marine-reserve idea, but they vary in opinion on how big those reserves should be. The Blue Ocean Institute calls for a five-year moratorium on Atlantic bluefin fishing everywhere. TheWWF further advocates that the industrial fishing methods that spread during the Age of Tuna — the drift nets, long lines, purse seines and spotter planes — be done away with. In their view, the “artisanal” single-hook-and-line fishing practices of old are the only way to sustainably hunt big and naturally scarce predators like bluefin.

But if we are to embark on a global project of ramping down tuna fishing, what are we to eat?

Until the modern era, the response to wild-game decline has been a primitive one: widespread destruction of the animals that can’t stand up to our hunting followed by the selection of a handful of ones that we can tame. Out of the many mammals that our forebears ate before the last ice age, humans selected four — cows, pigs, sheep and goats — to be their principal meats. Out of all the many birds that darkened the primeval skies, humans chose four — chickens, turkeys, ducks and geese — to be their poultry.

And indeed, this is a process that is taking shape rapidly with fish. Atlantic salmon are now commercially extinct throughout almost the entirety of their range but have become one of the most widely farmed fish in the world.

But while leaps have been made in taming marine fish, tuna, particularly bluefin tuna, may not make very much sense for the farm. Bluefin ranching as it is practiced in the Mediterranean, and with the Pacific bluefin in Japan and the southern bluefin in Australia, rightly faces strong environmental criticisms since it relies on catching juveniles from the wild and denies those baby bluefin a chance to reach adulthood and breed. Now, however, the final steps of fully taming or “closing the life cycle” of bluefin tuna are under way, which will make it possible for bluefin to be grown from an egg in a laboratory to a full-size adult. In such a system, an isolated “domestic” family of bluefin can be established that need not have any interaction with the wild at all. For several years Japan has been producing small amounts of closed-life-cycle Pacific bluefin (known as Kindai tuna in the market). In Europe and Australia, scientists have used light-manipulation technology as well as time-release hormone implants invented by the Israeli endocrinologist Yonathan Zohar to bring about the first large-scale captive spawning of Atlantic and southern bluefin.

But there are considerable complications ahead. As Richard Smullen, an Australia-based feed-company specialist working to come up with a suitable diet for farmed bluefin, explained: “The thing is the metabolic rate of these fish is very high compared to other fish; they swim fast, they heat their brains and vital organs and are warmer than the surrounding water, so this is energetically expensive. An analogy is like trying to feed an ultramarathon runner — they have the potential to eat a lot and not put on any weight.” Though Smullen says that it is possible to bring feed-conversion ratios for bluefin down, currently it may take 15 pounds of feed to produce a single pound of tuna, roughly 10 times as much as is needed for farmed salmon.

As fisheries decline globally, more and more countries are trying to replace their wild fish with farmed ones. Today 30 million tons of small forage fish are removed from the oceans yearly, with the majority of it going to feed farmed fish. If we end up farming bluefin on the same scale as we now farm salmon, the tuna, with its poor feed-conversion rate, may end up taking the food of the remaining wild fish that we haven’t yet got around to catching.

In addition there is little evidence to suggest that taming a species saves its wild forebear. Tiger farms in China have not halted tiger declines in the wild. Hundreds of millions of farmed Atlantic salmon have not stanched wild Atlantic salmon’s continued decline. Just because we can tame something doesn’t mean we should. The example of whales again rises. As the science historian D. Graham Burnett points out in a coming book on the Save the Whales movement, collaborations between American nuclear scientists and marine biologists were once proposed in the 1960s whereby tropical atolls, leveled by nuclear testing, could be used as giant corrals for the commercial farming of cetaceans. But fortunately for the whale — and I think for us too — we have come to see the whale not as something we fish for, not as something we farm, but as something we appreciate and maybe empathize with. Instead of expanding our stomachs or our wallets, whales have expanded our consciousness, our very humanity. So we have to ask ourselves, is there any rational argument for humans to eat bluefin tuna, wild, ranched or farmed? Is the fish really so special that no substitute will do? If the Japanese adapted to a higher-fat diet in half a century, could they and all sushi lovers not shift gears again and adapt to a sustainable diet?

It was in answer to these questions that I went looking for a farmed fish that could satisfy tuna-eaters at the sushi bar. A fish that had the dense “bite” of tuna but with a smaller ecological footprint — a Volkswagen instead of a Hummer.

My search led me to the coast of the Big Island of Hawaii, where I motored with a tall, optimistic Australian named Neil Anthony Sims. As we donned wetsuits, fins and scuba tanks, Sims rejoiced in telling me tales of his adopted land. Eventually we spat in our masks, adjusted our regulators and dived into the water above Sims’s farm — a huge underwater ziggurat that is the center of his company, Kona Blue Water Farms.

Until recently, most of the fish we’ve chosen to domesticate have been accidents. Salmon, striped bass, trout — we have chosen those species because we knew them as wild game. We seldom considered their biological profiles or whether they jibed well with the ecological limitations of a crowded planet.

But Neil Sims was a fisheries biologist before he was a fish farmer. And it was his direct personal experience with the limitations of fisheries management that persuaded him that fish farming, done right, was a better choice than fish catching.

Sims began his career in the remote Cook Islands of the South Pacific. There he was responsible for managing a giant snail called a trochus that produces an attractive pearly shell, valuable to native jewelers. Over half a decade, he implemented numerous management strategies. Nothing worked — not even shortening the harvest season drastically. The day after one season ended, he came across a bare-chested Polynesian elder who had pulled his dugout canoe onto the beach. Sims looked inside the boat and saw it filled with trochus.

“I yelled at him,” Sims remembers. “Then he yelled at me. He started to cry. Then I started to cry, and then the old bugger finally says: ‘Why? Why did you close the season? There are still some left!’ ” This moment prompted him to look beyond fishing, to an entirely different approach.

Sims was drawn to Hawaii, with its deep near-shore waters and strong currents — attributes favorable to aquaculture that he believed could make ocean farming sustainable. But the fish farming he found on arrival in Hawaii didn’t impress him. “People were trying milkfish and mullet,” Sims recalled. “They start with the letter ‘m’ and they’re all really kind of hmmmmm in the mouth, if you know what I mean.” Sims found the fish too bony and small, with loose, mushy flesh. This was important. Sims’s long-standing beat in the South Pacific had persuaded him that “there was an opportunity for a high-value, sushi-quality fish,” a fish that could fit into the dense-flesh category that the Age of Tuna had cultivated in Japan and indeed throughout the developed world.

After parsing many species he came across Seriola rivoliana. Known in Hawaiias kahala, it is a speedy, firm-fleshed animal of the same family as yellowtail and amberjack. They are only very distantly related to tuna and do not have tuna’s ruby red color, but they still have dense flesh and could easily pass for white albacore sushi. The fat content in Sims’s farmed kahala is around 30 percent, and indeed it is the presence of fat that accounts for much of a sushi fish’s tunalike flavor.

Sims was further intrigued when he found that kahala had barely been fished commercially. In their wild form kahala can carry ciguatera poison — a toxin sometimes deadly to humans that kahala ingest when they feed around coral reefs. But when kahala are isolated away from reefs and fed a traditional aquaculture diet of soy and fishmeal, they are ciguatera-free. (Sims asserts that ciguatera has never been detected in the flesh of his fish.) Since they have not been fished commercially, wild kahala populations are large and unlikely to be severely damaged through interaction with farmed fish. Moreover, kahala are much more “feed efficient” than tuna. The amount of fish required to produce a pound of kahala ranges from 1.6 pounds to 2 pounds, an order of magnitude better than bluefin. And Sims recently began feed trials using diets that contain no directly harvested forage fish. Lastly, unlike tuna, which require a tremendous investment in spawning technology, kahala are naturally fecund: they breed frequently, at least weekly, throughout the year.

THERE ARE, OF COURSE, those who would disagree with Sims’s approach. When I asked Casson Trenor, author of the 2009 book “Sustainable Sushi,” for his impression of the kahala as a farmed fish, he responded that the farming of any carnivore is “fighting the current.” “You may have a farm that has a more efficient protein ratio,” Trenor wrote me, “but produces more waste streams. Perhaps you have a feed pellet that knocks your feed conversion ratio down to 1 to 1, but you continue to host a rampant parasite infestation. . . . We need to identify fish that through their physiology and life history actually lend themselves to clean farming operations.” Trenor’s own compromise is to serve wild “small format” tuna like skipjack or albacore, fish that he feels can embrace the “principles of seasonality, local awareness and sustainability” that sushi originally expressed before it was “transformed through cultural misinterpretation and overzealous globalization into exactly the opposite.”

But as I plunged into the calm blue waters off Kona and inflated my diving vest to gain equilibrium in the water column, I couldn’t help thinking that in a world of environmental evils prosecuted against fish, the farming of a more efficient carnivore than a bluefin under the stewardship of a knowledgeable, environmentally conscious biologist was a good deal better than the rapacious industrial harvesting of “large format” tuna. Looking down at this “cathedral” of fish, as Sims called it, the possibility of a certain balance presented itself. Using technology developed over the last 10 years, Kona Blue has constructed diamond-shape cages that can be moored in the open ocean away from sensitive coastal areas. As I glided down, past the fish swimming in unison in their net pen, I felt a cautious optimism. The site of these pens had been carefully chosen; the swift currents meant that nutrientsdid not accumulate below the pens. And regular monitoring has found the fish to have no internal parasites, unlike the wild kahala. Sims’s commitment to transparency is also encouraging. He regularly posts water-quality reports on his Web site and presumably will do the same as the operation expands.

Sims waved me over to the side of the net pen. I floated above him, close enough to see that the fish actually seemed to recognize him. In what he would later describe to me as the “rock-star effect,” the fish crowded to be close to him. Sims spread his arms out wide and seemed to take in their adulation.

Sims has trademarked his kahala with the name Kona Kampachi — “Kona” for its point of origin, “Kampachi” for the similaranimal in Japan. They retail for $18 to $20 a pound in fillet form and to date have a tenuous foot in the market. Production reached more than a million pounds in 2008, about a third of the amount of bluefin caught in American waters that year. After a hiatus during most of 2009 and the first part of 2010 while Sims reconfigured his cages, the product will be reintroduced this July with even more capacity. Kona Kampachi may not have the rich ruby color of tuna (a color that is often enhanced artificially by “gassing” with carbon monoxide), but it is an extremely pleasant sushi experience. It satisfies the sashimi yen that has been created over the last 30 years — the yen for the firm, energy-rich musculature of a fast-swimming open-ocean fish.

Can we embrace a new set of species that we don’t know intimately in their wild form? Can we come to an understanding of which fish work for us as “seafood” and which fish don’t? I would hope so. The survival of the wild ocean could very well depend on it. I took one more look at Neil Sims floating with arms outstretched, his kahala finning in the current, each one mutely appraising this conductor of a silent concert. The only sound was the whir of bubbles rising by my ears.

SEAFOOD. HOW MANY species suffer those two mean English syllables? Other languages are no kinder. Romance European cultures use the expression “sea fruit,” while Slavs say “sea gifts.” So-called vegetarians rue the killing of farmed terrestrial animals but regularly eat wild fish. Kosher laws mandating merciful animal slaughter don’t apply to fish.

These thoughts were in my head recently when I got perhaps my last look at a wild bluefin tuna, just a month before the Deepwater Horizon rig exploded and collapsed into the Gulf of Mexico. I was 20-odd miles off the coast of Cape Hatteras, N.C., aboard the Sensation, a vessel chartered by the Tag-a-Giant Foundation, a nonprofit organization trying to decode the complex migration patterns of the bluefin and help lay the scientific foundation for the fish’s protection. Tag-a-Giant had been fishing for a couple days, and many people had sat in the fighting chair I now occupied, reeling in tuna after tuna. But for me this was a first. I had never caught a bluefin before.

In the past I would have wanted to savor the fight, to do battle with the fish with lighter, more “sporting” tackle. But considering everything I’d learned about tuna, humans and the chances of the great fish’s survival, it suddenly seemed infinitely more appropriate to fight this tuna with the full expression of humanity’s power. For in the end tuna are no match for us. We have in this final phase of exploitation achieved dominion over the entirety of the watery world, from inland lakes and rivers to the littoral zone to the continental shelf out to the abyssof the high seas. Sitting in the huge fighting chair with the huge rod and reel, in the well of the huge sportfishing vessel, it was inescapably apparent who had the edge.

As my bluefin breached, one of the scientists opened a door at the stern of the boat. A blue vinyl mat was laid down on the deck. The fish came through the door, still “hot,” banging its tail excitedly. But in an instant a biologist named Andre Boustany placed a moist cover over the tuna’s giant eye and a hydration hose in its mouth. The tuna motor mellowed, and at last the fish was beatifically still.

“Do you want to tag him?” Boustany asked me.

I took the sharp four-inch needle from his hand and positioned it just behind the fish’s dorsal fin. Pricking the skin slightly I started to pull my hand away.

“No,” Boustany said, “you gotta really stick it in there.”

Applying more pressure, I felt the needle slide into the flank, felt the resistance of the dense sushi flesh, raw and red and most certainly delicious. But for the first time in my life I felt tuna flesh for what it was: a living, perfect expression of a miraculous adaptation. An adaptation that allows bluefin to cross oceans at the speed of a battleship. An adaptation that should be savored in its own right as the most miraculous engine of a most miraculous animal, not as food.

Perhaps people will never come to feel about a tuna the way they have come to feel about whales. Whales are, after all, mammals: they have large brains; they nurse their young and breed slowly. All of that ensconces them in a kind of empathic cocoon, the warmth of which even the warmest-blooded tuna may never occupy. But what we can perhaps be persuaded to feel, viscerally, is that industrial fishing as it is practiced today against the bluefin and indeed against all the world’s great fish, the very tigers and lions of our era, is an act unbefitting our sentience. An act as pointless, small-minded and shortsighted as launching a harpoon into the flank of a whale.

Not Just Bees -- Scientists Say 1/4 of All Flowering Species Could Go Extinct

Human activity could spell end for a quarter of all flowering plants, with huge impact on food chain.
By Juliette Jowit, The Guardian | July 8, 2010

More than one-in-four of all flowering plants are under threat of extinction according to the latest report to confirm the ongoing destruction of much of the natural world by human activity.

As a result, many of nature's most colourful specimens could be lost to the world before scientists even discover them, claims the research, published today in the journal Proceedings of the Royal Society B.

The results reflect similar global studies of other species groups by the International Union for the Conservation of Nature, which estimates that one-in-five of all mammals, nearly one-in-three amphibians and one-in-eight birds are vulnerable to being wiped out completely. Later this year the results of a huge global analysis of all the world's estimated up to 400,000 plants by Royal Botanic Gardens, Kew, is due to be published by the IUCN as part of its ongoing mission to assess the state of all life on Earth.

"[This year] marks the International Year of Biodiversity," said Stuart Pimm of Duke University in North Carolina, USA, one of the authors of the report. "The focus of this celebration has often been on the species we know of, along with discussions on the unprecedented challenge of conserving this biodiversity in the face of threats such as habitat loss. However, by asking just how many species we will lose before they are even discovered, our study has revealed a figure that is truly alarming."

The researchers started by carrying out an independent review of how many flowering plants – which make up most of the plant kingdom – exist. By considering the rate at which new specimens are being described to science, adjusted to reflect the growing number of scientists over the years, and interviewing experts who focus on different groups such as orchids, irises or grasses, the team calculated that on top of the existing "best estimate" of 352,282 flowering plants there are another 10-20%, or 35,000-70,000, which have still to be officially discovered.

The second stage was to assess the level of threats from habitat loss due to clearing land for planting crops or trees, development, or indirect causes such as falling groundwater levels and pollution.

They started with a study published in the journal Endangered Species Research in 2008, which estimated that one-in-five known species were vulnerable to extinction.

However based on the fact that new species – like recent discoveries – are likely to be found in "biodiversity hotspots", where there are huge numbers of endemic species which are not widely distributed around the world, and a high level of habitat loss, they estimated that all so-far-undiscovered flowering plants were also at risk.

"If we take the number of species that are currently known to be threatened, and add to that those that are yet to be discovered, we can estimate that between 27% and 33% of all flowering plants will be threatened with extinction," said David Roberts, one of the co-authors, of the Durrell Institute of Conservation and Ecology at the University of Kent.

The paper adds: "These estimates are based on immediate threat, and do not consider further development of destructive factors - including climate disruption." The paper's third, lead, author was Lucas Joppa of Microsoft Research in Cambridge.

The warning comes as there is growing international recognition of the value of the natural world to humans in providing ecosystem services, from flood protection and medicines to spiritual spaces and enjoyment.

"Plants are the basis for much of life on earth with virtually all other species depending on them; if you get rid of those you get rid of a lot of the things above them," added Roberts.