Dennis Hedgecock wants to breed a better oyster to feed the world. Since 99 percent of the biosphere's volume is sea water, it's time to put it to work.
Oysters are a nearly perfect food. They've got vitamins from A to Z, and they pack a nutritious omega-3 acid punch in a low-calorie package. For juice-cleansing Angelenos, they're a no-brainer. (But the aphrodisiac properties of oysters are only in your mind, researchers say.)
While many animals are selectively cross-bred, oysters are the only animals to exhibit “hybrid vigor,” a dramatic boost in size or production that's achieved in many plants through cross-breeding. The technique turned corn from a small crop into a powerhouse, increasing its output sevenfold and making it a cheap ingredient to feed the planet. Without it, a box of cereal would cost around $20.
A soft-spoken but energetic professor of biological sciences at the University of Southern California, Hedgecock says it's actually a bit of a mystery what causes “vigor,” but here's how it's done: Researchers like him cross different strains of oysters. Then the puny, inbred offspring are crossed with each other. The result, sometimes, is big oysters that grow faster than their parents or grandparents.
Hedgecock has been working with Taylor Shellfish to establish an experimental breeding project on Catalina Island and in the Pacific Northwest. He has identified 350 different genes involved in oyster growth, and can easily breeze through an hour or more talking of little but bivalve genetics. Already he's grown an oyster twice as large as typical, and he thinks he can grow an “improved oyster” three times the size found in nature. The oysters are quite safe to eat, and delicious.
Cross-breeding for growth is vastly preferable to genetic engineering, he says. For one thing, genetic material almost always escapes to the wild. And Hedgecock says it's arrogant to assume that genetic manipulation can create better bivalves when scientists are still trying to understand how the oyster genome works.
So it's back to the tanks each year, testing more inbred crosses. Oysters typically have to mature for two to three years before they can be gobbled up with a bit of mignonette.
Hedgecock is a quiet man, but his words gain volume and velocity as he describes the obstacles facing seafood farming in the United States. While farmed fish make up half of the fish eaten worldwide, the U.S. lags behind. Part of this, says Hedgecock, arises from the American public's view that aquaculture presents new dangers — such as diseases in farmed fish migrating into wild stocks. He says such problems represent only a tiny fraction of aquaculture.
Hedgecock shakes his head, clearly frustrated at what he considers to be our unfounded fears. “As a result, this country imports 86 percent of the seafood we eat,” he says.
Bivalves may offer the best way to safely and economically grow tomorrow's food. “We've got 7 billion people to feed,” he notes. “It truly would be a disaster not to increase aquaculture.”