Date: Tue, 4 Jun, 1996
Amazon Manatees
By PETER MUELLO
Associated Press Writer

MANAUS, Brazil (AP) -- Overhunting and destruction of habitat are threatening to wipe out the world's only fresh-water manatee. Some scientists fear it could go the way of the Steller sea cow, which was hunted to extinction just 30 years after its discovery in 1741.
"This species doesn't exist outside the Amazon," said Dr. Vera da Silva, head of the Aquatic Mammals Laboratory at the National Institute of Amazon Research.
"If it becomes extinct here, it will be gone for good."

The institute in this Amazon jungle city, 1,800 miles northwest of Rio de Janeiro, hopes its research will improve chances for recovery of Brazil's fresh-water manatee. Begun in 1975, the institute's Manatee Project has provided scientists with new information about the habits and makeup of the creature that Brazilians call "peixe-boi" -- Portuguese for "ox-fish."
"Back then we knew absolutely nothing about its biology or physiology," da Silva said.
"Even now, we don't know how many there are."

What they discovered was an unusual and primitive mammal that can't even maintain a constant body temperature. Like a reptile, its temperature varies with the environment. Yet the manatee is uniquely adapted to the warm waters and flood-and-drought cycles of the Amazon. When the water is high and food abundant, an adult eats up to 110 pounds of water plants a day. In the dry season, it can go for six months without food.

Scientists also found that the manatee plays a crucial role in the intricate Amazon food chain.
"It transforms up to 40 percent of its food into smaller particles and nutrients that feed many fish, micro-organisms and phytoplankton," da Silva said.

Like its larger sea-going cousins in the coastal waters of Florida and Africa, the Amazon manatee belongs to a branch of mammals that includes the elephant, the aardvark and the hyrax. Its cigar-shaped body and whiskered face give it a walrus-like appearance. The manatee has been protected in Brazil since 1967, but poaching is a problem.

Manatee oil is used for cooking and in home remedies for everything from rheumatism to bronchitis. The meat, fried and stored in its own fat, is a dish much appreciated in the Amazon interior because it keeps for months without refrigeration. Francisco Cavalcanti, a retired but unrepentant poacher, says manatee hides also are sold to tanneries, which use them to make glue, shoe soles, loom parts and gaskets, belts and hoses for locomotives and heavy machinery.
"It's better than cowhide, stronger and thicker," he said.

Big -- up to 1,100 pounds -- slow and docile, the manatee has no natural enemies except man. When European colonizers came three centuries ago, the Amazon teemed with them.

In a 1658 journal, Jesuit priest Antonio Vieira wrote how Indians in the eastern Amazon loaded more than 20 ships a year with manatee meat and oil for Dutch traders. From 1776 to 1778, the Portuguese Royal Fishery near the Amazon River port of Santarem registered the entry of 58 tons of manatee meat and 1,613 barrels of oil.

Females with young are the easiest prey. Hunters set wooden stakes in the water to locate the animal, then harpoon it to bring it to the surface.
"When it comes up, the hunter shoves two sticks up its nostrils," da Silva said.
"The manatee can't breath through its mouth and suffocates."

The orphans often are kept as pets in tanks or on a tether through a hole bored in the fan-shaped tail. But few hunters realize how much milk the calves need, and they usually sicken from malnourishment.
"They get weaker and weaker, and when they're almost dead someone remembers that INPA exists and donates them to us," da Silva said.

The institute keeps up to 20 manatees in concrete-and-glass tanks. Each day, the calves are fed five quarts of formula with milk, butter, egg yolk, melon and vitamins. They may live 45 years, but they never can return to the wild.
"They've lost their fear of man, and that is their only chance for survival," da Silva said. INPA hopes to place them in fish farms or in special conservation units. Another idea is to use them to control the spread of water plants.

In the late 1970s, the government electric company in the Amazon, Eletronorte, asked for help to clear the reservoir of the Curua-una hydroelectric dam, glutted with weeds that blocked sunlight and reduced oxygen in the water. The institute put 42 manatees in the reservoir, and the plant cover receded. But the followup studies weren't completed, and INPA couldn't prove conclusively that the manatees were responsible for the result.



Back to MENU