Shortage of ocean fish rocks the 'cradle of aquaculture' into action
Manila — In a water tank outside Manila last year, a school of milkfish was bred for the first time in captivity. While it is a long way from lab tank to frying pan, the achievement nonetheless elated the longtime Asian growers of Chanos chanos.m After all, milkfish "farming" in lakes and tidal areas has not changed much since Magellan landed on Philippines shores in 1521.
The small fry of milkfish have always had to be caught in the wild, a practice as onorous as chicken-king Frank Perdue's having to chase down wild chicks for his farms.
The new breeding technique -- known as spontaneous spawning of pond-grown fish -- will allow generation of fast-breeding varieties that could bring two or three "crops" a year instead of just one.
"We're really domesticating fish," said Dr. Ziad H. Shehadeh, director general of the International Center for Living Aquatic Resources Management, the organization set up in 1977 to coordinate Asia's long-term fishing development.
Just 15 years ago, Asia experienced an agricultural revolution when scientists bred a new, sturdier rice. Now the little-noticed advancement at the Southeast Asian Fisheries Development Center (SEAFDEC) outside Manila has been seen as no small-try revolution for another ancient Asian delicacy -- fish.
What fish and chips are to Britain, fish and rice are to Asia. Because rice is not a complete diet, fish protein has been Asia's main supplement, with an average 25 to 35 kilograms a year eaten in most countries.
Along with carp, mullet, and tilapias, the milkfish ranks the highest in potential expansion for Asia's practice of aqua-culture, which ranges from finfish to oysters, and yet is still swimming along slowly.
Why the excitement over fish-tank genetics?
In the 1970s, Asia's ocean fishing sank like a lead weight. From Japan to Sri Lanka, catches are smaller, caused mainly by overfishing, higher fuel costs, and loss of fishing grounds under the new 200-mile offshore economic zones.
Naturally, to replace the rapidly-depleting ocean catches, Asia now turns to a food source that, acre for acre, produces protein cheaper and more efficiently than land farming.
Therein lies a catch, however, since fish farming could compete for land with traditional agriculture. But Asia's seafood-consuming nations, especially Japan , could push aquaculture through any economic barriers.
While marine fishing has the potential to increase with improved technology, the United Nation's Food and Agriculture Organization and other groups are forecasting that fish production through aquaculture could increase from between 5 and 10 times in the next decade -- although 2 to 3 times appears more realistic to researchers.
At present, fish farming accounts for about 10 percent, or 5 to 6 million metric tons, of total world fish production.
"I'm not sure we can replace the losses in traditional fishing," Dr. Shehadeh says. "We're still scratching the surface in aquaculture. The force of science still has yet to be felt --better feed, seed, and water processes."
Fortunately, Asia is the cradle of the ancient art of aquaculture, beginning with Chinese carp fishing some 3,500 years ago. In Indonesia, which may hold the most aquaculture potential along its shores, the "tambak" system of brackish-water fish farming was probably started in the 13th century by convicts who were forbidden to practice agriculture or other professions.
Today, four-fifths of all university-level aquaculture studies are in Asia. And the region claims 80 percent of the world's fish farming, produced on some 5 million acres of ponds, rivers, tidal flats, or lagoons. Estimates of potential aquaculture land use ranges up to 50 million acres.
While shrimp and prawn farming has advanced the most in the last decade, those high-priced species are mainly sold to developed countries for middle-income consumers and as a way for Asia's developing nations to earn foreign exchange. Almost half of the Asian Development Bank loans in fishing, for instance, go to develop the shrimp industry. But, say critics, "The private sector can look after itself."
For domestic food consumption to feed Asia's growing populations, however, researchers are turning to tried-and-true backyard Asian fish. An estimated 750 ,000 to 1 million acres of milkfish farming are already cultivated in Indonesia, Taiwan, and the Philippines, mostly for domestic consumption.
At the heart of milkfish expansion, as in all aquaculture, is induced breeding of female fish in the ponds. "We still don't know yet why captive fish will not breed," Dr. Shehadeh says. SEAFDEC's breakthough took six years, and scientists around the world await repetition of the induced spawning this year.
At present, collection of young from the wild incurs high costs -- over 1 billion milkfish fry were trapped last year in Philippines waters, involving many nurseries and middlemen and a high dependency on mother nature.
In developed nations, poultry farming did not "fly" until good genetic stock as well as better feed came out of the lab. Aquaculture awaits the same level of husbandry -- growing fish like cattle or chickens in feedlots, stuffing them to the gills until they're ready for market. Israel, perhaps the most advanced nation in aquaculture, has learned to provide automatic feed and oxygen into high-yielding fish ponds.
Like the popular slogan "appropriate technology," used by development experts , fish biologists are beginning to look for the "appropriate species" that would fit well into local social and economic conditions. Milkfish, for instance, can often rely on pond bacteria for food rather than high-cost feed that other species might need. Shrimp breeders, for instance, recently discovered that a young shrimp with one eye purposely broke will, strangely, reproduce in captivity. At present, shrimp farming still relies on ocean capture of fry.
The Philippines has plans to end fish imports and become self-sufficient through greater milkfish farming. Outside Manila, the freshwater lake of Laguna de Bay is home to some of the highest milkfish yields yet. In Malaysia, aquaculture now accounts for 80 percent of government spending on fisheries. Even landlocked, mountainous Nepal last year received a $11.8 million loan from the asian Development Bank to nurture a budding aquaculture industry for the food-poor country.
Rather than just expand present methods, however, work is under way to exercise greater control over the stocks with more intensive farming. Use of cages and pens, rather than open ponds, helps cut demand for land. Special emphasis is being given to air-breathing species, specifically catfish, which would require less water flow and allow denser populations.
At India's Central Island Fisheries Research Institute, researchers are developing catfish for cage-growing in unused swamps, where oxygen levels are low. And some scientists believe that deep ocean currents full of rich nutrients can be diverted into coastal "sea ranches."
One challenging potential will be a combination fish-rice-animal farming, in which cross-fertilization benefits the whole farmlot.
At present, less than 1 percent of Southeast Asia's irrigated rice fields are used for culturing fish. In Thailand's Pongsuwana region, the fish culture brings more income than the rice. Such differences cause tenant farmers in Java to cede their entire rice crop over the landowners in exchange for the right to culture fish in the fields. Thus, any fish-rice farming could have serious implications for land ownership in Asia.
In Malaysia, experiments with raising ducks overm fish ponds shortened the culture period of fish by two months with the fertilizing effect of the bird droppings. Similar results were reported in Taiwan when pigs are grown near Chinese carp farms. In Philippines, such simultaneous farming methods are known as palay-isdan, dating back to antiquity.
But increasing pesticide and fertilizer use on new rice varieties, plus parasites in animal manure, have been shown to damage fish, posing high hudrles for scientists to overcome.
Although more biological breakthroughs are needed, especially in breeding techniques, perhaps the longer-range problems are social and economic. The aquaculture field today is dominated by biologists who, says Dr. Shehadeh, have to be tempered by economists.
For instance, investors in the Philippines are buying up fish farms that yield four tons of milkfish per hectare (about 2 1/2 acres). But local farmers say they can get more profit if they skip the high cost of feed and fertilizer, settling for two tons a hectare.
The international aquatic center, funded largely by the Ford Foundation and US aid, finds aquaculture's weakest link is a lack of skilled people. "There are more projects than people to run them," says Dr. Shehadeh. The center maintains eight full-time professional and many part-time consultants on a meager budget of $1.8 million this year. SEAFDEC has begun training several dozen "Asian aquaculturists." And the World Bank is spending $38 million for a Philippine fishery training system.
Still, most aquaculture is still traditional -- father-to-son knowledge -- while the more profitable operations tend not to reveal their secrets.