Lapu-lapu can be raised commercially-A A +A
Sunday, March 10, 2013
IT'S a common knowledge that Chinese restaurant is not complete without a bubbling tank full of grouper. Asia's most demanded reef fish, grouper fetches up to P6,000 per piece in Hong Kong and Singapore. In the blockbuster movie, Drunken Master, steamed grouper was one of the many dishes Jackie Chan's character requests during an attempted meal-theft.
Most of the fish comes from the Philippines, as the country is considered the center of the Coral Triangle, a region between the Pacific and Indian Oceans that harbors 75 percent of all known species of plants and animals that thrive among coral reefs.
"The grouper fish is widely cultured in the pristine waters of the Philippines, where it is known as lapu-lapu," one scribe notes. "This commodity is valued for its superb taste and its big potential in the export market."
Unfortunately, four decades of unregulated cyanide and dynamite fishing -- plus a rising trend to target vulnerable spawning areas – are threatening wild stocks of lapu-lapu with total collapse.
"Our wild stocks for lapu-lapu are fast becoming depleted because of overfishing as a result of their high price and big market abroad," said Dr. Rafael D. Guerrero III, a national scientist and the co-proprietor of Aquatic biosystems, a consulting and marketing firm based in Bay, Laguna.
The fish is named after Cebu's chieftain, who killed Ferdinand Magellan in the Battle of Mactan. Internationally, it is known as grouper, which comes from the Portuguese word garoupa, meaning "fish." Actually, grouper is the common name for numerous members of marine fish in the sea bass family. They commonly grow to 50-100 pounds (they can reach up to 750 pounds), but most market fish are about 5 to 20 pounds.
Today, groupers are facing extinction. In fact, 20 of the world's 162 known species are threatened with extinction according to a survey conducted by Conservation International (CI). Since the fish have slow reproductive rates, they are particularly vulnerable to overharvesting.
"This shows that over-fishing could decimate another major food and economic resource for humans, similar to the loss of the cod stocks off New England and Canada that has put thousands of people out of work," warned Roger McManus, a senior director of CI's Marine Program.
In the Philippines, Dr. Guerrero believes that there is still hope for lapu-lapu fishery. "To conserve them, fishing pressure should be regulated and marine reserves where they are protected should be maintained," he suggested. "Breeding them in captivity is another way."
There are at least 20 species of groupers that abound in Philippine seas but only a few are suited for farming in marine ponds and cages. Grouper fingerlings used for stocking ponds and cages are caught from the wild by fishermen and sold to the growers. The major source of grouper fry are in the provinces of Pangasinan, Cavite, Mindoro, Quezon, Masbate, Bulacan, Cagayan, South Cotabato and Negros Occidental.
Grouper fry are collected in nominal quantities using various devices like scare lines and brush piles. The size of fry varies from one to nine centimeters and is collected by fish traps from coastal waters near mangrove areas.
In raising lapu-lapu, one of the biggest things a grower should consider is the site. According to experts, the site should: (1) be in calm water like sheltered lagoons, coves, islets, bay, behind an island or a river mouth. This is to avoid damage caused by strong winds, waves and current; (2) have salinity ranging between 32-34 parts per thousand; (3) have water depth not less than 3 meters during low tide; (4) have good water exchange to maintain good water quality; and (5) be relatively free from any source of pollution and protected from environmental hazards such as typhoons, floods, and erosions, among others. It must be accessible but secured from vandals and poachers.
Groupers are carnivorous and voracious fish. "The common method of feeding the grouper is by giving it live fish like tilapia," Guerrero said. "This can be done by either rearing Mozambique tilapia in a pond and then harvesting this to feed to grouper stocked in another pond, or both grouper and the ‘feed fish’ are raised together in the same pond."
In experiments conducted in Bicol University's College of Fishery in Tabaco, Albay using the grouper-tilapia polyculture system, the ratio of one grouper to 20 tilapia was found effective. This means that for every hectare, 20,000 fingerlings of tilapia and 1,000 fingerlings of grouper are stocked. The young of tilapia fingerlings which mature in the pond become the natural feed of the grouper.
Groupers can also be raised in cages. Feeding is generally by means of trash fish given at frequencies ranging from twice a day to every two to three days. Feeding to satiation is commonly applied. It takes around four to five kilograms of trash fish to produce a kilogram of grouper.
"The culture period for grouper in ponds and cages takes four to six months, depending on the size of fingerlings stocked and management," Guerrero said. "Marketable sizes for the fish range from 0.5 to 1.0 kilogram per fish."
Published in the Sun.Star Davao newspaper on March 11, 2013.