How to Grow a Giant Tuna
By R. W. APPLE Jr. ENSENADA, Mexico -

TOOLING his black BMW south along Interstate 5, Philippe Charat banters with his passengers and chats on his cellphone in English, Spanish and French. No matter what the language, the subject remains the same: fish.

We're headed from San Diego to this booming city of 400,000 in Baja California, 75 miles from the international border, and from there by launch out into the ocean, around a headland called Punta Banda and into Puerto Escondido Bay. There, Mr. Charat runs an unusual aquaculture business - an underwater feedlot for the creatures that he calls "the kings of the sea": Thunnus thynnus orientalis, or Pacific bluefin tuna.

This is the fish prized above all others by connoisseurs of sushi and sashimi, the one whose belly meat, called toro, commands the highest prices on Japanese restaurant menus (with the exception of the potentially poisonous fugu, or blowfish, which is not nearly as widely sold). At its best, when the fat content is high, when the fish has been meticulously handled, the flesh is fabulously tender and buttery, ranging in color from a soft pink to a deep, winy red. Obviously too luscious to cook. Begging to be eaten raw.

Unlike salmon, tuna has not yet been successfully farmed - that is, raised in captivity from egg to maturity - though Mr. Charat predicts it will happen one day. For now, all bluefin must be caught in the wild, not only the Pacific species but also its giant, biologically similar Atlantic cousin, which is perhaps slightly less desirable from a gastronomic viewpoint.

Tuna Pens of Puerto Escondido, south side of Pt Banda
Tuna Pens of Puerto Escondido, south side of Pt Banda
Photo by David Hopps

What Mr. Charat has done here, building on the experience of an operation that he studied in Australia, is to ensure that all the bluefin he catches, not just a few, become prime specimens. His boats net the fish, tons at a time, as they cruise along the coast, 20 to 30 miles offshore.

Then, the tuna are towed at less than two miles an hour, still in the water in specially designed enclosures, to Puerto Escondido Bay. There they live the life of Riley, splashing happily about in 16 huge circular pens, gaining weight and building their fat content on a sardine diet - all the fish they can eat, three times every day, six days a week, for four to eight months.

"You take a run-of-the-mill fish, a so-so fish, and turn it into a superstar," Mr. Charat said.

The tuna are caught between June and August, as they swim between Magdalena Bay, near the southern tip of Baja California, and Monterey Bay, south of San Francisco. They are sold between October and March, by which time they weigh up to 190 pounds.

When Mr. Charat's company, Maricultura del Norte, gets an order, an appropriate number of fattened tuna are harvested. That gives him an edge over conventional suppliers: they have to sell as soon as their boats dock, whether the demand is high or not. He sells, as he said, "when I want to."

ONE day in January, my wife, Betsey, and I visited the feedlot with Mr. Charat and our mutual friend, Sam Popkin, a tuna-crazed professor of political science at the University of California at San Diego. It was harvest day, with the sky blue and the sun hot at midmorning. Maricultura's agent at Tokyo's fish market, Tsukiji, had ordered 100 large and 300 small bluefin.

At Christmastime, when the demand peaks, Maricultura sometimes harvests as many as 900 tuna in a single day, working from sunrise to sunset.

Tsukiji pays the highest prices in the world, but its buyers insist on quality - tuna without bruises or blemishes, with vividly colored flesh, with maximum oil and fat content. The current price for a gutted bluefin, with head and tail on, runs about $9.50 a pound for small fish, $12.75 a pound for medium fish and even more for larger fish. A 410-pound tuna was sold at Tsukiji for a record $160,000 last year.

The meat sells at retail for as much as $45 a pound, despite the lasting slump in the Japanese economy.

Mr. Charat takes extraordinary steps to meet Tsukiji standards - some during the harvest, others before it starts. The fish are towed here very slowly to minimize enzyme stress, which can adversely affect flavor. Those to be harvested at a particular time are isolated from those which are not, lest they thrash about and damage one another. The sardines they are fed, caught locally by Maricultura's own trawler, the Noble Provider, are so good that Mr. Charat distributes a few from time to time to friends in the food business, who consider them vastly superior to those on sale in fish markets.

To avoid damage to their livers from overeating, the tuna are fed only six days a week; it would never do to have a bay full of fish with crises de foie. And on those six days, the sardines are broadcast across the surface of the water to force the big fish to compete aggressively for food. Some farmed salmon are criticized because, having no need to work for nourishment, they develop a flabby texture.

"It takes a tough man to make a tender tuna," Professor Popkin observed as each of the various procedures and safeguards was explained to us.

The harvest was a gaudy, melodramatic spectacle in primary colors, like a picture fashioned with a child's poster paints. The workmen wore green or yellow rubberized trousers with orange bibs; a blue tarpaulin on the work barge was stained a vivid red by streams of fish blood as the day wore on. Yet everything was done so efficiently and so quickly, with so little apparent suffering by the fish, that it scarcely seemed as primal as it clearly was.

Divers in black wet suits and yellow flippers started by raising a barrier inside one of the pens, separating a dozen or so tuna from the rest. Next they grabbed the fish, one by one, one hand on the tail and the other in the gills, and hoisted them onto the barge, where another crew of workers held them in place. Instantly that team spiked each tuna in the head, killing it, cut a main artery behind the gills to bleed it, and ran a fine steel wire down the fish's spinal column, paralyzing it immediately.

Another team, astonishingly deft like the first, then took over, cutting out the gills and guts in one swift motion and tossing the bluefin into a 32-degree saline water solution.

The whole process took only about 50 seconds - a short enough period, Mr. Charat told us, to preserve the tuna's quality in two ways: by avoiding the formation of excessive lactic acid and by preventing the fish's blood temperature from rising after it has left the sea.

When the workers took a break, they presented their visitors with a late breakfast, a pailful of sea urchins fresh out of the ocean. A whack with the back of a knife and the rich, creamy roes were laid bare. The taste of the first startled us. It was overwhelmingly salty, but the rest, rinsed in fresh water, were blissfully sweet and custard-like, with no hint of the metallic flavor that mars the elderly uni served at second-rate sushi bars.

They sure beat doughnuts.

A TWISTING trail brought Mr. Charat, who is 62, to Ensenada. The son of a French mother and a Russian father, he left Paris with his family as an infant. They lived in Cuba and in Texas, but by 1957 the elder Charat was in the fishing business in Mexico. The son showed an entrepreneurial flair at Harvard, helping two friends start the Harvard Student Agencies, which have gone from strength to strength, publishing, for example, the widely read "Let's Go" guides. He went on to the Harvard Business School.

In 1973, Mr. Charat entered the shrimp fishing business in the Gulf of Mexico. But in 1981 his company was nationalized. In 1983, he bought three tuna purse seiners, selling his catch in Mexico and in Samoa.

Thirteen years later, he started his present business, following a visit, as part of a Mexican delegation, to a tuna-fattening operation at Port Lincoln in South Australia, west of Adelaide. The Australians utilized frozen sardines; he could do a lot better, Mr. Charat reasoned, with the fresh sardines in ample supply in this corner of the world.

And so he has. A Mexican citizen, he holds a 50-year concession from the Mexican government. Maricultura fattened 30 tons of tuna the first year, 60 the second, 100 the third, 300 the fourth. Another big increase is expected this year. Before too long Mr. Charat hopes to begin fattening yellowfin tuna and yellowtail, a kind of amberjack that the Japanese call hamachi, at a new installation in Magdalena Bay, which is 600 miles south of here.

He already has one competitor in this region, and five more have been authorized by the government. The business is well established in Australia. And according to Chris Purcell of Ocean View Fisheries, a fish wholesaler in Halifax, Nova Scotia, about a dozen fishermen in nearby St. Margaret's Bay fatten Atlantic bluefin on a small scale, maybe 40 to 50 fish each.

The world's, and especially Japan's, appetite for tuna seems insatiable. The question is whether stocks of bluefin can withstand the pressure. Already, the giant Atlantic bluefin, which can reach up to 1,500 pounds, is listed as endangered by the Monterey Aquarium, which monitors such matters. The southern Pacific bluefin, which is caught off Australia, has also been overfished, but so far the northern Pacific bluefin, caught here, appears to be in better shape.

About 95 percent of Maricultura's output goes to Japan, with about half of that ending up at Tsukiji, where it is labeled "LA" after the airport from which it is shipped - a mark that guarantees it a premium price. The other 5 percent is sold in San Diego and Los Angeles, mostly to top restaurants.

Chilly from their cold-water bath, the fish are cleaned, weighed, tagged and measured before being placed with cold gel packs in plastic-lined boxes to keep them fresh. If they are harvested on Thursday, for example, they are packed on Friday morning and trucked to Los Angeles International Airport on Friday afternoon. They arrive in Tokyo on Sunday, local time, and go on sale at 5 a.m. Monday. Most of them will be consumed by Wednesday at the latest.

That may sound like a very long time. But in fact it is almost ideal; like a number of other fish, such as Dover sole, bluefin only reaches peak flavor and texture four to six days after it has emerged from the water.

Mr. Charat demonstrated that the night before we visited Ensenada. At George's at the Cove, one of San Diego's leading restaurants, the chef, Trey Foshee, prepared a loin of two-day-old Maricultura tuna in several ways. A grilled rib steak was superb, but a slice of the same fish, served raw, was not quite as rich-tasting, and not at all as tender, as we had expected.

"Wait two or three days," Mr. Charat said. "It's not ready."

Professor Popkin took a piece of the bluefin loin home, kept it in his refrigerator for 48 hours and then served it as sashimi to his family. It was perfect, he reported, the melt-in-the-mouth stuff you dream about.