ONE DAY IN 1979, A YOUNG GRAD STUDENT WAS sitting hunched over a microscope in the attic of a hatchery when he realized he had created a new kind of oyster, an oyster nature had never designed.

Thirty-one years later Standish Allen still remembers the moment: he was counting chromosomes through a microscope in an unfinished attic with sawdust on the floor and exposed insulation along the walls. He was smelling the salty, seaweedy air of the Maine coast, and he was seeing, for the first time, a baby oyster with extra chromosomes.

His first reaction was something unprintable, followed by "We did it!" His second reaction was a typical grad school move: He stopped abruptly, jumped up, and hustled downstairs to find his thesis adviser so he could show him his results.

For more than a year Allen had been testing techniques for forcing additional chromosomes into the Eastern oyster, Crassostrea virginica, the native species that grows along the Atlantic and Gulf coasts of America. While nature gave oysters two sets of chromosomes, making them diploids, Allen was trying to pack his oysters with three sets of chromosomes, making them triploids. Those extra chromosomes would help Allen's oysters grow fat faster, and those qualities, in theory, should quickly turn these triploid seed oysters into a moneymaker for oyster farmers — not just in Maine but in any other coastal waters where oyster aquaculture was an option.

A triploid oyster, with its triple set of chromosomes, was designed to avoid the market drawbacks of traditional oysters. Nature's oysters are diploids, and they are seldom sold or eaten during the summer months when they're growing gonads to produce sperm and eggs. Those are the months, according to custom and common sense, when oysters are seldom good eating: too crammed with gonads or too watery after spawning. Come September, the first of the "R" months, spawned-out oysters are beginning to recover and fatten up with meat, and watermen and oyster growers can finally bring them to market.

Allen's oyster, on the other hand, was an oyster for all seasons. Triploids are sterile oysters. They usually don't grow gonads and don't bother spawning, letting them put all their energy year-round into growing meat. As a result the yield from an invented oyster is up to twice the yield from a natural oyster. These fat little oysters can go to market any time of the year — not just Thanksgiving and Christmas and Easter. Seafood lovers could start their crab feasts with appetizers of fresh, plump, summertime oysters.

It would take twenty-six years, however, for this invented oyster to travel from Maine to Maryland where it may now play an important role in reviving oyster farming in the state (see Up From the Bottom). Standish Allen, the young grad student with the old New England name, would become a persistent pioneer who would change oyster farming around the world. When his oyster invention finally reached the Chesapeake Bay, it would land the soft-spoken biologist in the middle of a heated and historic debate about how to restore the ecological health of the ecosystem. And then his new oyster would help revolutionize oyster farming in this depleted estuary.

Counting Chromosomes Looking through a microscope in 1979, Standish Allen knew he had invented a triploid oyster when he counted three sets of 10 chromosomes, for a total of 30 (top right). Natural oysters are diploid, with only two sets, for a total of 20 chromosomes (top left). The counting process took half an hour per oyster. By 1993, he could use a high-tech flow cytometer to do the counting for an oyster with four sets of chromosomes (bottom). That spike on the graph meant Allen and Ximing Guo had invented another new oyster — a tetraploid. Photographs and graph courtesy of Standish Allen.

INVENTIONS OFTEN COME FROM unexpected people in unexpected places. The first airplane would be invented by two bicycle mechanics from Ohio, the first personal computer by two dropouts working in a garage, the first triploid oyster by a new grad student working in a state with no history of successful oyster farming. Not even a young Standish Allen could have expected that.

The invention of triploid oysters in Maine in 1979 was a sudden leap for a career that had been slow off the mark. After graduating from Franklin and Marshall College, Allen had worked construction for two years building horse barns in Pennsylvania and swimming pools in his hometown of Foxboro, Massachusetts, all the while waiting for his girlfriend to finish college so they could marry and head for Maine. Once there, he worked odd jobs again before talking his way into graduate school at the University of Maine. And there he finally found a focus for his energies in the busy aquaculture scene that was being born in front of his eyes.

On a hill above the tree-lined Damariscotta River, scientists and grad students at the Darling Marine Center were pushing hard with Sea Grant funding to create an aquaculture industry in Maine. As an aquaculture student, Allen was learning the science alongside entrepreneurs who were learning the business. It was the birth and baptism by water of a hands-on "bucket biologist." The scientists he was working with were trying new techniques for farming oysters, hard clams, soft clams, scallops, and salmon. Anything that worked with one species was tested with others.

Sometimes what didn't work with one species was also tried on others. For his work with triploid oysters Allen adapted a technique Norwegians had tried on salmon. He tried forcing extra chromosomes into oyster eggs, using a chemical called cytochalasin B. While the chemical never worked well to create a salmon product for Maine, it proved one of the keys to inventing triploid oysters.

The other key was timing. The chemical, Allen learned, had to be applied during a small window of time shortly after an oyster egg meets up with an oyster sperm. After an oyster egg is fertilized, it begins to throw off female chromosomes it does not need as it takes up a set of male chromosomes. If Allen added cytochalasin B at the right moment, the egg would keep both sets of female chromosomes while still adding one set from the male sperm. Voila: a triploid oyster with three sets of chromosomes.

If he added the chemical too early or too late, if he added too much or too little, if the water was too warm or too cold, if the females were not ripe, if the males were not ripe, if dozens of lab steps were not followed exactly — he would get dead oyster larvae. The triploids he created in the lab soon proved themselves in field trials, emerging as fatter and juicier than most of nature's oysters. What Allen had discovered, through dozens of trials and dozens of errors, was a precise but painstaking lab technique. What he had proved was a principle: science could build an all-season oyster.

Triploid Vs. Diploid Oyster Growth A triploid clearly grows faster than a diploid oyster, as the graph above demonstrates. In this trial in a high-disease area of the York River, triploid versions of Crassostrea virginica, the native Chesapeake oyster, grew 50 percent heavier than diploids in less than two years. With their fast growth, triploids usually go to market in less than two years. At right is a fat triploid oyster, just shucked and ready for eating. Graph courtesy of Standish Allen and photograph by Michael W. Fincham.

His advisor, oyster biologist Herb Hidu, soon clambered up to the attic and peered into Allen's microscope. His mentor, fish biologist John Stanley, reviewed his slides. Both confirmed his findings and shortly thereafter the University of Maine awarded the young grad student a Master's degree in Marine Biology.

AN INVENTION, ALLEN SOON discovered, can sometimes be an idea ahead of its time. While the telephone made Alexander Graham Bell a rich man, he died claiming his greatest invention was the "photophone," a device that could transmit sound on a beam of light. His concept is crucial to contemporary fiber optics, but it was irrelevant in the late 19th century. The triploid oyster seemed destined for a similar fate.

The first time the newly invented oyster was tried for commercial farming, it flopped. It grew fast, but oyster farmers in Maine were not interested. The oyster industry, struggling to get started, was not ready to try a biotech invention that seemed to require a lot of laboratory manipulation with toxic chemicals. The triploid seemed an irrelevant invention.

When Allen left Maine, feeling shunned by the industry, he headed for the West Coast, where his invented oyster first began to pay off in commercial farming. Arriving at the University of Washington for his Ph.D. work, he discovered a thriving oyster industry with farmers and hatchery operators who wanted to try out triploids. Working in Kenneth Chew's lab with support from Washington Sea Grant, Allen teamed up with Sandra Downing, another grad student, to apply his chemical technique and create a triploid version of another oyster species, Crassostrea gigas. This Japanese oyster had been transplanted to the West Coast and renamed the Pacific Oyster.

Anu Frank-Lawale examines one of the tetraploid brood oysters at the VIMS Aquaculture Genetics and Breeding Technology Center. Tetraploid oysters are spawned with diploid oysters to create triploids for growout on oyster farms. Classically trained in genetics at Scotland's University of Stirling, Frank-Lawale now serves as Breeding Research Manager. Credit: by Michael W. Fincham.

An Oyster Primer Three species of oysters, one native and two imported, have been considered for aquaculture in the Chesapeake Bay. Crassostrea virginica — The Eastern Oyster is native to the U.S. where it has been fished and farmed from the North Atlantic down to the Gulf of Mexico. Disease epidemics of MSX and Dermo began devastating oyster stocks in Delaware Bay and the southern Chesapeake Bay in the late 1950s. New disease outbreaks in the 1980s reduced harvests from fishing and farming to all-time lows and raised interest in introducing a non-native oyster. Crassostrea gigas — This Japanese and Korean species has been renamed the Pacific oyster and transplanted for aquaculture to a number of countries, including the West Coast of the U.S., Canada and Mexico, the British Isles, France, Portugal, Australia, and New Zealand. The species was rejected for use in Maryland in 1932. Starting in 1993, gigas was tested in Virginia waters before also being rejected in 1998. Crassostrea ariakensis — Starting in 1998, the Chinese Suminoe oyster, native to coastal China, was evaluated for introduction into the Chesapeake. After laboratory experiments and field trials with sterile triploids, the species was rejected in April 2009, ending a long-time interest in using a foreign oyster to replace or supplement the native virginica oyster. Illustration sources: Crassostrea virginica, from The American Oyster Crassostrea virginica (Gmelin), P.S. Galtsoff , 1964; Crassostrea gigas and Crassostrea ariakensis, Courtesy of Christopher Langdon.

Working with Coast Oyster Company, one of the largest commercial oyster companies in the world, Allen and Downing next adapted his tricky chemical techniques to the task of creating triploids in large batches. The solutions Allen and Downing came up with were sometimes messy but mostly successful, with their commercial batches averaging 70 to 90 percent triploids. The bucket biologist had joined the biotech revolution.

A technical video from that era shows Allen as a young-looking scientist lecturing on triploids. He's slim, sandy-haired, and clean-shaven, and wearing huge horn-rimmed glasses that give him the earnest look of an eager undergraduate. But now he had his Ph.D. And large oyster hatcheries on the West Coast were selling triploids to oyster growers, they in turn were selling them to restaurants, and restaurants were selling them to customers.

The day he passed his final exams, Allen and his friends celebrated at a Seattle bar where he could order triploid oysters on the half shell. Slurping down one of his invented oysters, he couldn't help joking, "My work here is done." Then he headed back to the East Coast where he would come up with his next oyster.

THE FIRST STEP IN THE INVENTION of his next new oyster came when Ximing Guo left China, the birthplace of aquaculture and the source for 70 percent of the world's farmed oysters. A native of Qindao, on the northern coast of China, Guo came to the University of Washington where he read Standish Allen's early work on triploid oysters and decided on his Ph.D. project: he would create another new species: a tetraploid oyster with four sets of chromosomes.

Guo tried and failed, then tried again and failed, and then kept trying. "There are probably five different ways to theoretically make a tetraploid from God's diploid creature," says Allen, "and in each case he met with failure." Guo's Ph.D. dissertation turned into a summary of all his failed attempts at creating tetraploid oysters.

If necessity can be the mother of invention, then sometimes serendipity can be the father, and in Allen's case, serendipity meant finding the right partner. It's hard to imagine Orville Wright without Wilbur, or Steve Jobs without Steve Wozniak. And it's unlikely Allen would have come up with his next invention if he hadn't hooked up with Ximing Guo.

Why struggle so long to invent yet another new oyster? Because Guo knew that tetraploid oysters would be the best way to create triploid oysters. In the math of mating, a tetraploid with four sets of chromosomes could be mated with a diploid, a natural oyster with two sets. The offspring would be triploid oysters with three sets — but triploids created without messing around with toxic chemicals. The magic chemical Allen used with triploids was also a major carcinogen, and the Food and Drug Administration was getting ready to ban its use in commercial hatcheries. The invention of tetraploid breeding could make triploid oysters commercially workable almost anywhere in the world.

When Allen landed his first full-time faculty job in 1989 at the Haskins Shellfish Research Laboratory in Bivalve, New Jersey, he remembered Ximing Guo and his theory about creating tetraploids. He also remembered that all of Guo's grad-school experiments flopped. The reason: diploid eggs, Guo found, were not large enough to hold two extra sets of chromosomes in their nucleus. Out of his multiple failures, however, came a hypothesis: perhaps the only way to create tetraploids was to start with large eggs from triploids.

It seemed a hopeless hypothesis since triploids weren't supposed to have eggs, and the search for a tetraploid oyster may have ended there, but for serendipity. In all his work with triploids in West Coast labs and hatcheries, Allen would occasionally spy through his microscope a triploid oyster with eggs. Never very many eggs — but perhaps enough eggs to test Guo's hypothesis. "On occasion, triploids will make eggs," he explains, "and on those occasions you can use the eggs because they are fertile." Biology, says Allen, is the science of exceptions, and in his lab work he had seen the exceptions.

Allen helped recruit Guo to the Haskins Lab, and in 1993 the two new faculty began searching for that uncommon creature — a triploid oyster with big eggs. An egg-bearing triploid is so rare, one researcher named it "the Blue Moon," and finding enough of them meant somebody had to slice open thousands of triploid oysters and examine the tissue of each one under a dissecting microscope. Allen now had grad students and lab workers to handle much of the grunt work, but once triploid eggs were found, he and Guo had to go back into the lab with the chemical cytochalasin B. Working in a controlled lab setting, they used the chemical to pack those triploid eggs with a fourth set of chromosomes, and then they grew their altered eggs into oyster babies. Finally they began counting their chromosomes.

Allen didn't have to use a microscope this time. Now he had access to a flow cytometer, an expensive device that could count chromosomes faster than 30 pairs of eyeballs squinting through 30 microscopes. Staring at the cytometer screen with his one set of eyeballs, Allen found himself waiting for a spike in the far right column. That would signal the presence of a fourth set of chromosomes.

On the first oyster in the first batch, Allen saw the spike pop up that said tetraploid. It was the second "we-did-it" moment in his life as a scientist. It's an instant that freezes the mind: verification or falsification, the verdict is announced, the envelope is opened, the winners are named. Sudden proof comes rarely in biology, a science built on the slow accretion of field observation and lab experiments and endless quantification. But for Allen the answer arrived in a second, in the blink of an eye. Allen and Guo had invented another oyster never seen in nature.

The new oyster would soon be patented — the second patent Allen has his name on — and their tetraploid technique is now used to create triploids for oyster farming in more than six states and nearly a dozen countries with more regions trying it every year. His second invention had saved his first invention.

Staring at the screen Allen flashed back to his first discovery moment 12 years earlier hunched over a microscope in an attic in Maine. "Those are the two pinnacle moments of discovery," Allen now says. "In my career, it comes down to two." Once again, he had to show somebody. He stopped, grabbed a visiting researcher as a witness and had him sign his lab book.

A DECADE LATER, WEARING HIP waders and a Boston Red Sox baseball cap, Allen was sloshing slowly along the wide tidal flats off the mouth of the York River, checking on dozens of oyster bags lined up in neat columns in front of the hilltop home of the Virginia Institute of Marine Science. The year was 2003 and I was meeting with him to find out why triploids were needed in the Chesapeake Bay.

Stocky with a two-day stubble on a sun-baked face, Allen seemed to enjoy the wet work, the hands-on hauling of bags and racks that are the daily drill of oyster aquaculture. Reaching down, he hauled up a wire mesh bag full of the Bay's native oysters and shook it. The rattling oysters gave a dull sound like empty castanets clacking together. That comes from hollow boxes, oyster shells empty of meat, banging against each other. "That sounds like dead oysters to me," he said.

By 2003, triploid oysters seemed to be an invention whose time had come in the Chesapeake. With populations of native oysters devastated by MSX and Dermo diseases, the Virginia Seafood Council began using sterile triploids as a safe way to test foreign oysters before introducing them en masse into the Chesapeake Bay. As the inventor of sterile oysters Allen seemed a logical choice to organize the incursion — especially since he could now use tetraploids for creating large batches. In 1997 the state legislature gave the Virginia Institute of Marine Science (VIMS) new funds to recruit the godfather of triploids away from Rutgers.

Allen had already become a player in Chesapeake oyster politics. In their first love affair with a foreign oyster, Virginia growers had courted the Japanese oyster, Crassostrea gigas — and Allen had supplied the sterile oysters for field trials while still working from his hatchery at Rutgers. The affair, however, did not end well. Local consumers didn't find the new bivalve delicious, claiming it left a metallic taste on the tongue, and the Virginia Seafood Council in 1998 went looking for another love. The dismissal left a little bit of a bad taste with Allen, a biologist who projects a sober demeanor but often leaks sardonic humor at unexpected moments. "East Coast oyster eaters," he said, "are snobs about their oysters."

Wading forward across the shallows in front of VIMS, Allen led me to a heavier, fatter-looking bag. When he hoisted it and shook it he got a different sound: instead of empty castanets, he got thick, clunky thuds like rocks banging together. That comes from oysters chock full of live oyster meat. "This," he said, "sounds like money to me."

These oysters were triploids created from a Chinese oyster now called Crassostrea ariakensis. The oysters in the bag were large and healthy, fast-growing and disease resistant. They may have been the second choice after the Japanese species, but the Chinese oyster and the Chesapeake Bay seemed a marriage made somewhere in oyster heaven.

Any marriage, however, would have to survive a long, contentious engagement while scientists asked questions about the new love interest. Could the non-native oyster grow well and sell well to East Coast oyster eaters, could they reproduce well, could they could create reefs, could they filter large volumes of water? If the triploid trials came up with the right answers, the result could be a large-scale introduction of a reproducing Chinese oyster that might revive a commercial fishery and perhaps help restore Chesapeake Bay.

It was a challenge that excited Allen. His first job at VIMS had been to design and direct an Aquatic Genetics and Breeding Technology Center, and creating large numbers of Chinese triploids was one of its first achievements. Sitting outside the Center's hatchery, Allen was soon grasping for superlatives as he described the potential of ariakensis. "It's just phenomenal," he said. "It's like a super oyster." That was high praise from a thoughtful biologist who clearly had high hopes for this non-native. Solving the Chesapeake's oyster drought with either a native or non-native species could be "life-defining," he admitted. Right up there with three times inventing triploid oysters.

His career in the Chesapeake, however, would soon be full of unexpected experiences — not all of them pinnacle moments. When the early field trials showed the Chinese oyster to be a fast grower, the soft-spoken Allen found himself in the hot center of a historic debate. On one side were oyster farmers who saw a commercial payoff and scientists who saw an ecological payoff from a new reef-building, water-filtering oyster. Opposing them were scientists and environmentalists who argued just as passionately that the foreign oysters could introduce yet another new disease in the estuary or outcompete the native oyster for habitat. As the debate ramped up, Congress held hearings, the National Academy of Sciences ran a major review on the risks of non-native oysters, and the U.S. Army Corps of Engineers organized a multi-year Environmental Impact Statement.

All that interest brought down intense scrutiny on the triploid oyster factory Allen was running at the VIMS hatchery. While most triploid oysters born of tetraploids are sterile, a small percentage, well below one percent, can turn fertile and reproduce. For every batch of 1,000 Chinese triploids he sent out for field trials, Allen was allowed no more than one fertile reversion.

That proved a tough standard when he tried to launch his first million oyster field test. According to the original plan, ten oyster packers would each get 100,000 tiny Chinese oysters to plant, grow, and harvest — but only if his triploid batch passed the reversion test. In a sample of three thousand ariakensis oysters, however, Allen found four fertile oysters. That averaged out at 1.3 oysters per thousand, putting him over the limit, and requiring him, in effect, to flunk a million oysters. Allen was sitting in front of a flow cytometer when he saw the numbers, but doesn't remember the experience as a pinnacle moment.

Several days later on a sweaty August afternoon, he gave shovels to two of his young lab assistants and showed them where to dig a grave. The next day, on the grounds of the Virginia Institute of Marine Science, with a minimum of ceremony, with one reporter looking on, Allen and his crew buried nearly a million tiny Chinese oysters on a small knoll overlooking the York River. Not a pinnacle moment either, but an unusual moment in the history of oyster science.

When they finished shoveling dirt over the oysters and tamping down the grave, they went back to work breeding more Chinese oysters for more field trials. In all his crew would create nearly five million ariakensis oysters for test plantings in the Bay.

The death blow came in April of 2009 when the final decision on Chinese oysters came down. After spending five years and millions of dollars on an Environmental Impact Statement, the Army Corps of Engineers announced that the Chinese oyster was out, the native oyster was in. The decision makers on the study's Executive Committee included the natural resource agencies in Maryland and Virginia, the Potomac River Fisheries Commission, the Atlantic States Marine Fisheries Commission, and NOAA, EPA, and the Fish and Wildlife Service. As a filter feeder the Chinese oyster might accumulate viruses harmful to humans, they said. And it might outcompete the native oyster.

Triploid oysters like these were an invention worth a patent. When Standish Allen first created triploids in 1979, as a grad student working with the native East Coast oyster, he published his results. In 1984, while working on his Ph.D., Allen created triploids again, this time with the Pacific oyster. He was denied a patent on triploids because his technique was no longer original — as a result of his earlier publication. Ironically, his losing case, Ex parte Allen, became a landmark in legal history, since it established that patents could be granted on living animals altered by science. Allen is now one of the patent holders for tetraploid oysters, an invention he created in 1994. Credit: by Michael W. Fincham.

Oyster growers began lifting the last Chinese oysters out of the York, the Rappahannock, the Little Wicomico, the Yeocomico, Fishing Creek, and Folly Creek. By June 1, 2009, Allen's Chinese oyster was gone from the Chesapeake. For the Virginia seafood industry, an 18-year romance with foreign oysters had ended in a bitter divorce. For both aquaculture and restoration, Maryland and Virginia would be betting the farm on the disease-ravaged native oyster.

Over eight years of field trials, Allen had to perform five burials for Chinese oysters, creating next to the VIMS hatchery a small cemetery of unmarked oyster graves. The symbolism was obvious to him. We do a lot of research, he told me, and then we bury it.

A YEAR AFTER HIS CHINESE oysters were voted out of the Chesapeake, Allen is back walking the beach in front of VIMS, showing me racks of oysters lined up in neat rows along the tidal shallows. Out on the flats, three of his hatchery workers are wading among the racks, lifting and moving bags of oysters. All these are native virginica oysters that he's been crossbreeding for fast growth and disease resistance, the traits that may represent the last, best hopes for oyster farming in the Chesapeake (see Survivor: Chesapeake).

Allen's sandy hair is now streaked with gray, and he's grown a beard, also graying, that gives him a grizzled professor look that works well when he goes into sardonic mode. He can slip into that mode easily when he's talking about the ariakensis decision, but for the most part he's surprisingly optimistic — in his restrained style — about the future. And with good reason.

The long, failed courtship with Chinese oysters, according to Allen, launched nothing less than a revolution in oyster aquaculture in Virginia. For more than a century, most oyster farmers followed a simple routine: dump wild seed on productive nursery bottoms and come back three years later in hopes of a harvest. When disease began devastating oyster grounds in the late 1950s, most Virginia seafood packers went out of business, but some began buying oysters from out-of-state suppliers. Most of the oysters now shucked and sold in the Chesapeake region have come from elsewhere, especially from Gulf states like Louisiana where the recent oil spill may soon cut the supply of oysters to the whole country.

To take part in the Chinese oyster trials, however, Virginia processors had to adopt a more intensive approach. They had to use bags and floats and off-bottom cages and carefully monitor and record growth and mortality. "When they ran out of ariakensis to test," says Allen, "they were left with the gear that enabled them to try growing our native species."

Between 2005 and last year, more private hatcheries geared up, and the production and planting of hatchery-grown oyster seed more than quadrupled. By 2009, the sale of farmed oysters from Virginia had increased ten fold. "The whole ariakensis thing impelled native oyster aquaculture," says Allen. "It just shoved it out the door. They went from being packers to being aquaculturists."

As Chinese oysters made their exit, the oyster that began to take center stage was the one he first invented thirty years earlier. Oyster farmers in Virginia began trying a triploid version of the native virginica oyster. Call it an accident of history. During the large-scale field trials, oyster growers in Virginia were asked to plant a small sample of triploid natives (1,000 oysters) next to their large plantings of Chinese triploids (100,000 oysters). Scientists wanted to have an "equivalency test," a comparison of the two triploid species, native versus non-native. Virginia growers were soon impressed with how fast the Chesapeake triploids grew.

Those Virginia growers ended up as early adopters for Chesapeake triploids. "We are working with it because that's the available option we have," says A.J. Erskine, an aquaculture specialist with both Bevans Oyster Company and Cowart Seafood. "I would anticipate triploids are going to be much more valuable for us than diploids." The invented oyster grows fast enough that it can often be harvested before MSX or Dermo diseases can kill it off. And it can be harvested all year, says Erskine. "It allows us to market that oyster during the summer."

For Standish Allen, the man who created triploids out of three species — the native virginica oyster, the Japanese gigas oyster and the Chinese ariakensis oyster — this last payoff is a low-key kind of pinnacle moment: The inventor finally gets to see one of his inventions catch on in the Chesapeake Bay.