Pick up a newspaper in Japan these days and you'll almost always find a story in it about the state of bluefin tuna somewhere in the world.

Just a few recent headlines have included: "Fishing industry being eaten alive"; "Tuna shortage has Japan fearing for its next sushi"; "European fleets accused of overfishing bluefin tuna"; "Bluefin tuna export ban plan rejected"; "Bluefin farming proceeds swimmingly."

So what's really going on?

Is the entire fishing industry really on the verge of worldwide collapse?

Is Japan's appetite for sushi driving tuna to extinction?

Will fish farms solve the problem of overfishing?

As for fisheries facing worldwide collapse, the short answer is that they are not. Although some species are overfished, threatened, endangered or even at risk of extinction, many fisheries around the world have been certified as sustainable by respected independent organizations such as the London-based Marine Stewardship Council.

Indeed, at the 5th World Fisheries Congress held in Yokohama in October, 2008, the United Nation's Food and Agriculture Organization (FAO) presented its "Status of World Fish Stocks" report, showing that 1 percent were classed as "Recovering" (from near-extinction); 7 percent were "Depleted" (critically endangered or extinct); 17 percent were "Overexploited" (threatened to endangered); 52 percent were "Fully Exploited" (sustainable to threatened); 20 percent were "Moderately Exploited" (sustainable); and 3 percent were "Underexploited" (sustainable).

Neither is Japan's considerable appetite for sushi driving tuna to extinction — not least because sushi is now popular around the world, especially in China, the United States and many European countries, so Japan is somewhat "off the hook." In addition, conservation groups such as the U.S.-based Blue Ocean Institute and the Environmental Defense Fund, as well as the cutting-edge Monterey Bay Aquarium in California, have published guides with titles such as "Ocean Friendly Sushi" and "The Seafood Watch Sustainable Seafood Guide" that are increasingly influencing consumers, restaurants and retail outlets.

With regard to fish farms, however, the answer has to be uncertain, since these are highly controversial — and indeed, they are illegal in Alaska. This is not only because of their possibly dangerous use of drugs, pollution of surrounding waters and genetic mutations caused by escaped stock mixing with wild stock, but also because valuable fish kept in them, such as bluefin tuna, are fed vast amounts of smaller fish such as sardines and mackerel that contain less mercury and more good cholesterols (EPA and DHA) than tuna, thus making them a healthier choice for human consumption.

Let's go back to the biggest player in newspaper headlines about the fishing industry, its "rock star" — the bluefin tuna.

What, exactly, is a bluefin tuna?

Scientists have categorized at least three species of bluefin tuna: Atlantic or northern bluefin (Thunnus thynnus); Pacific bluefin (Thunnus orientalis); and southern bluefin (Thunnus maccoyii).

To confuse matters more, in Japanese, both the Atlantic (northern) and Pacific bluefin tunas are called hon maguro (true tuna) or kuro maguro (black tuna), while their juveniles are all called meji. Southern bluefin, meanwhile, are called minami maguro (southern tuna).

Although a number of governments, regulatory agencies and scientific committees are offering assessments — often conflicting — of the status of the various tuna populations, an aggregation of their views as of 2008 has it that Atlantic tunas are critically endangered in the eastern Atlantic (including the Mediterranean Sea) and endangered in the western Atlantic; Pacific bluefins are fully exploited, or possibly overexploited; and southern bluefins are overexploited and possibly endangered.

One of the problems in accurately evaluating the relative stability of tuna stocks is due to what Hiroyuki Kuroda of Japan's Fisheries Research Agency (FRA) diplomatically calls "human induced uncertainty."

Kuroda says that regulatory agencies believe stock assessments of southern bluefin tuna, which are fished mainly by Australian and New Zealand companies, are under-reported and that TAC (total allowable catch) quotas — largely determined by ABC (acceptable biological catch) projections made by scientific entities such as the University of Tokyo's Ocean Research Institute — are ignored.

Pacific bluefin tuna, on the other hand, according to the FRA's Yukio Takeuchi, are more accurately reported due to the longstanding participation of local governments and fishing cooperatives in Japan, off whose shores most of the fish are captured.

In contrast, the assessments of Atlantic bluefin tuna stocks, especially in the Mediterranean, are compromised by a significant amount of illegal fishing and the influence of criminal organizations such as the Sicilian Mafia.

Despite such uncertainties, however, the spring of 2010 was made a little brighter in Japan when the 175-nation Convention on International Trade in Endangered Species (CITES), at its March meeting in Qatar, rejected Monaco's proposal for a complete ban on exports of Atlantic bluefin tuna. Monaco's position was chiefly supported by the U.S. and Norway, while Japan was successful in lobbying the great majority of CITES member nations to reject it.

Japan currently imports about 2,500 tons of Atlantic bluefin annually, some 70-80 percent of global exports, with the bulk of that tonnage caught in the Mediterranean, where the fisheries are regulated by the International Commission for the Conservation of Atlantic Tuna (ICCAT).

Prior to the CITES meet in Qatar, ICCAT — which Greenpeace scathingly suggests might equally well stand for the "International Commission to Catch All Tuna" — had already cut the TAC for Atlantic bluefin for 2010 from a proposed 19,950 tons to 13,500 tons.

The average Japanese consumer was, though, rather indifferent to news of the TAC reduction, since imported Atlantic bluefin tuna comprises less than 1 percent of Japan's annual consumption of tuna.

However, precise tuna statistics are a little hard to track in Japan, since different government agencies and NGOs categorize tuna species in different ways.

For example, the Japan Fisheries Agency (JFA) includes skipjack tuna (Katsuwonus pelamis), called katsuo in Japanese, in its tuna figures, along with yellowfin tuna (Thunnus albacares; kihada maguro), bigeye tuna (Thunnus obesus; mebachi maguro), albacore tuna (Thunnus alalunga; bin-naga), bluefin tuna (both Atlantic and Pacific), and southern bluefin. Meanwhile, another branch of government, the Ministry of Agriculture, Forestry and Fisheries (MAFF), lumps the six main tuna species into one category — with skipjack a separate, standalone category altogether.

The JFA's latest figures, from 2006, for tuna landings at Japanese ports, including both foreign and domestic deliveries, show a total of 851,000 tons. Of that, 379,000 tons, or 45 percent, was skipjack. The remaining 472,000 tons was mostly comprised of yellowfin (183,000 tons; 21 percent) and bigeye (173,000 tons; 20 percent), with albacore at 57,000 tons (7 percent), bluefin at 44,000 tons (5 percent) and southern bluefin at 15,000 tons (2 percent).

By way of comparison, the MAFF's latest figures, from 2008, for tuna produced by Japanese fisheries lists 217,000 tons for all six tuna species and 304,000 tons for skipjack, adding up to 521,000 tons in total.

All in all, the JFA's figures for percentages of total tuna catches in Japan are fairly consistent with estimates worldwide. Globally, skipjack make up 50-60 percent of the catch, with yellowfin at 24-30 percent, bigeye at 8-10 percent, albacore at 5-7 percent and all bluefin varieties at just 1-3 percent.

The MAFF's 2008 report on fisheries production in Japan lists a total of 5.5 million tons, with 4.4 million tons for marine fisheries and 1.1 million for aquaculture and inland fisheries. The ministry's report also shows that Japan, with 1.8 percent of the world's population, consumes 10 percent of the world's fish as its nearly 130 million people eat their way through almost 70 kg per capita per year, amounting to some 9 million tons. Simple arithmetic then tells us that Japan imports about 3.5 million tons of seafood products annually.

And to reiterate: The average annual import of Atlantic bluefin tuna over the past few years has been just 2,500 tons.

So in reality, the tussle over a ban on exports of Atlantic bluefin has been a tempest in a teapot in Japan.

The world's most expensive fish transactions ever have involved sales of Pacific bluefin caught in Japan by ippon zuri (one hook, one line) fishermen out of Oma port in Aomori Prefecture, the northernmost point on Honshu, the country's main island.

These fish are caught in the dangerous waters of the Tsugaru Strait between Honshu and Japan's northern island of Hokkaido, which connects the Pacific Ocean and the Sea of Japan. The warm Kuroshio Current, which originates off eastern Taiwan and primarily flows up past Honshu's eastern coasts, brings the tuna from July to January via a branch that flows through the Sea of Japan then out to the Pacific through the Tsugaru Strait, which is only 20 km across at its narrowest. Each year in early January, the first auction of big, fresh end-of-season Oma bluefins at Tsukiji Fish Market in Tokyo — the world's biggest by far — always brings astronomical prices for both symbolic and promotional reasons.

A 202 kg Pacific bluefin from Oma sold for $173,000 ($860/kg) on Jan. 5, 2001, and a 232 kg specimen from the same port fetched $175,000 ($750/kg) on Jan. 6, 2010. Then just last week, on Jan. 5, a 342 kg monster from Toi in Hokkaido, across the Tsugaru Strait from Oma, set a new world record when it sold for $391,000 ($1,143/kg). Fish such as these go to high-end sushi restaurants where a single small plate of o-toro (fatty belly meat) might cost the diner ¥10,000 ($111) or more.

Customers at regular sushi shops, or the increasingly popular kaiten zushi (revolving sushi bars), will most likely be served yellowfin tuna in the spring, bigeye tuna in summer and fall and southern bluefin in winter. Prices for akami (red meat) from the upper body of a frozen bigeye or yellowfin might sell for as little as ¥160 ($1.77) for a plate with two pieces of sushi on it.

As of September 2009, according to the JFA, the nation's fishing companies had nearly 25,000 tons of frozen bluefin (Atlantic, Pacific and southern) in storage — equivalent to about 10 years of current imports. However, demand for bluefin in Japan, represented by annual spending on the product per household, fell by 33 percent between 1998 and 2008 — from ¥9,000 to ¥6,000.

Less newsworthy perhaps, but more important economically, was the 37.5 percent rise in prices for low-quality frozen bigeye tuna landed at Misaki in the city of Miura, Kanagawa Prefecture, one of Japan's leading tuna ports, between January 2010 (¥400/kg) and April 2010 (¥550 kg). Increasingly higher prices and shorter supplies of bigeye are anticipated due to major reductions in the Japanese and Taiwanese long-line fleets, which mainly target bigeye on lines extending many miles and using up to 2,500 hooks. Those reductions follow conservation-driven moves by Japanese and Taiwanese government agencies, the UN's FAO and several leading global NGOs due to the long-liners' appalling by-catch of turtles, seabirds and sharks.

Overall, including all frozen bigeye from low-quality ones to the best, prices at all Japan's main tuna ports were around ¥950/ kg in January and February 2010, with fresh bigeye averaging ¥1,100/ kg.

By comparison, frozen bluefin (Atlantic, Pacific and southern) averaged ¥1,600/ kg in those two months, while fresh bluefin fetched ¥4,500/ kg in January due to the usual new year spending splurges, then fell to just ¥1,150/ kg in February.

Meanwhile, frozen yellowfin were worth about ¥600/ kg in the first two months of 2010, and nearly twice that (¥1,150/ kg) for the fresh product, while albacore — the least valuable of the six main species in the genus Thunnus, averaged ¥255/ kg frozen and ¥300/ kg fresh.

So, if bluefin tuna make up a very small and shrinking share of the sushi market, what can the sushi-lover expect in the future?

The Marine Stewardship Council, which assesses fisheries world-wide and issues its eco-label to those it certifies as sustainable, currently lists 86 such fisheries, including three tuna fisheries — or four if skipjack tuna is included.

They are: The American Albacore Fishing Association (AAFA), the American Western Fishboat Owners Association (WFOA) and the Canadian Highly Migratory Species Foundation (CHMSF) — all three of which fish for albacore in the North Pacific, although the AAFA also takes them from the South Pacific.

The fourth fishery is the Tosakatsuo Suisan pole-and-line skipjack (katsuo) fleet that fishes in Suruga Bay out of Yaizu Port, Shizuoka Prefecture, and is presently Japan's only MSC-certified tuna fishery.

What all these four fleets have in common is that they use one of two hook-and-line techniques rather than nets.

The pole-and-line method, used by the Japanese katsuo boats and U.S. albacore boats in the South Pacific, involves a crew of up to a dozen fishermen equipped with long fiberglass poles (formerly they were bamboo) with a single hook on a line attached to them. When a school of fish is located, they stop the boat and drift along with the school, casting their unbaited hooks into its midst and yanking the fish onto the boat by back-swinging the reel-less poles. This method captures the fish in excellent condition, does not impact the environment and does not produce a by-catch of other species.

Because of the number of people aboard them, these vessels are necessarily large — typically around 300 tons — and they make trips lasting about three months and freeze their catch at sea as the fish are caught.

In contrast, the U.S. and Canadian albacore boats fishing in the eastern North Pacific use a hook-and-line method called "troll and jig."

Here, of course, it is important not to confuse "trolling" with "trawling" or "trollers" with "trawlers." Trawling is dragging a net through the water, either along the bottom or at mid-water — and in Canada, in fact, where I did most of my 20-odd years of commercial fishing, trawlers were called "draggers."

Trolling, however, involves pulling a set of artificial lures, called "jigs," along or just below the surface. Originally jigs were made of dyed chicken feathers and metal heads with colored glass eyes and a hook on the end. Today's jigs are usually plastic squid with chromed lead heads, often tarted up with prismatic tape as well as multifaceted glass eyes. Since they call up the image of the costumes once worn by hoochie-coochie dancers, Canadian trollermen call them "hoochies."

In tuna trolling, large wooden or aluminum poles are fastened to the sides of the fishing boat and five or six braided nylon lines with monofilament leaders are attached to each pole, each line trailing a hoochie. Since albacore are fast swimmers, the boats — which often average just 10 to 20 tons and carry only two or three fishermen — cruise through a school at around 6 to 9 knots. When fish begin to strike the jigs, fishermen use small bronze hydraulic winches, called tuna pullers, to haul each individual fish toward the boat. Once the leader comes within range, the fisherman grabs it by hand and flips the fish onto the deck.

Trolling, like pole-and-line fishing, is extremely target specific, yields a high-quality product, and does not impact the environment.

While some trollers freeze their catch on board, many carry ice instead, and fish packed in it will keep for up to three weeks if they are bled right away (since tuna are warm-blooded). A 20-ton fish hold will typically have seven tons of ice in it before setting out for the fishing grounds.

While albacore stocks are the most secure of any tuna populations, albacore are not a popular sushi fish. The meat is pink rather than red, and in a sushi shop it's known as bin-toro. Canned albacore, on the other hand is the premium product, sold as white-meat tuna normally at three times the price per can as tuna from other species, or from skipjack.

The best alternative to bluefin tuna for the sushi trade would appear to be yellowfin.

Yellowfin tuna, called ahi in Hawaii, is the staple of the sushi market there, since it is caught locally by fleets of handline fishermen in small boats and delivered fresh to market daily.

At the present time, three yellowfin tuna fisheries are under assessment by the MSC and are expected to be certified as sustainable and issued with its eco-label in the near future. These are: the Maldives' pole-and-line and handline fishery in the Indian Ocean, which produces 20,000 tons of yellowfin per year; Mexico's Baja California pole-and-line fishery; and the southeastern U.S. pelagic longline tuna fishery in the North Atlantic, which catches both yellowfin (55 percent) and bigeye (45 percent) species and would be the first longline tuna fishery to be certified as sustainable.

Given that, excepting skipjack, yellowfin make up the largest, and one of the most stable, global populations of tuna, and number 10 to 30 times those of all bluefin tuna, it would make good sense to begin a marketing campaign to promote them as a gourmet sushi product and a desirable alternative to bluefin.

That campaign might also usefully address the mystique of bluefin tuna's fatty o-toro and chu-toro belly-meat sushi which, far from being a "tradition" in Japan, is a rather recent proclivity. In fact, hon maguro was not a popular Japanese food until the mid 19th century, when larger fishing boats and nets were developed.

And tastes do change, even in Japan.

In 2009, for example, salmon became the most popular marine fare in Japan, followed by squid and tuna — even though salmon wasn't even in the top three in 1965, when jack mackerel (aji) was the most popular, followed by squid (ika) and mackerel (saba). Then in 1997, mackerel took over the top spot, while squid — the perennial runner-up — remained in second place, with salmon the third most popular.

However, as concerns about the environment — as well as for taste and prices — begin to affect consumer behaviors in Japan, it may one day soon be possible to see a shift by tuna sushi-lovers away from the endangered bluefin to far more sustainable species such as bigeye or yellowfin.

Perhaps we should take a tasty tip from the Monterey Bay Aquarium, which features a yellowfin tuna on the cover of its "Sustainable Seafood Guide."

Hillel Wright is the author of two books of poetry, a collection of short stories and two novels, including "All Worldly Pursuits," which narrates the career of fictional fisherman Wiley Moon. Hillel Wright currently teaches Modern and Postmodern North American Literature in the Graduate School of Daito Bunka University, Tokyo, and is Japan Correspondent for the London-based Fishing News International newspaper.

Which tuna is which of all those fish in the seas?

Tuna are in the family Scombridae, which comprises about 55 species of fish, including the mackerels and bonitos. The list below identifies all the tuna, as follows: English name — Latin nameJapanese name(s).

Atlantic bluefin — Thunnus thynnushon maguro / kuro maguro

Northern bluefin — (as above)

Pacific bluefin — Thunnus orientalishon maguro / kuro maguro

Southern bluefin — Thunnus maccoyiiminami maguro

Bigeye — Thunnus obesusmebachi maguro

Yellowfin — Thunnus albacareskihada maguro

Albacore — Thunnus alalungabin - naga maguro / bin-cho maguro

Skipjack — Katsuwonus pelamiskatsuo

Japanese names for juvenile tunas:

Bluefin — meji; bigeye — daruma; yellowfin — kimeji; albacore — tombo; skipjack — not named, as they are too small to bite on a hook.

Hawaiian names for tuna (in case you want to order sushi there) are:

Bigeye — ahi; yellowfin — ahi; albacore — tombo; skipjack — aku