War, Other Factors Taking Toll on the Mammals : Persian Gulf’s Dugongs Fight to Survive

Pollution, hunting, reclamation projects and even the Iran-Iraq war are threatening the Persian Gulf’s dugongs, sea cows that survive on underwater grasses along the shore.

Environmental scientists are looking for ways to save them, including the use of a communications satellites to help track them.

The mammals are believed to be the source of ancient seafaring legends of mermaids.

Dugongs disappeared from the gulf after Iraq bombed Iran’s Nowruz oil wells in 1983, causing a massive oil slick. Environmentalists found 38 dead dugongs on Saudi Arabian beaches at the time.

Pollution a Threat

The Persian Gulf, a major source of oil, is one of the most heavily polluted regions in the world and this also poses a threat to the animals, environmental protection experts here say. They add that sea reclamation projects in the waterway are killing the grasses dugongs feed on.

At the same time, dugongs are hunted or caught accidentally in fishermen’s nets. Their meat is eaten as a delicacy in some Persian Gulf areas.

Taking up the task of saving the mammals, the environmental scientists plan to attach radio transmitters to two dugongs in hopes finding out more about their habits.

A herd of about 700 dugongs was sighted by one of the scientists, Anthony Preen of Australia, in the gulf this past March but he said seeing that many at one time does not mean they are not an endangered species.

Radio Experiment

The sighting prompted Preen and other scientists from Australia’s James Cook University to try the radio experiment. Saudi Arabia’s Meteorological and Environmental Protection Agency welcomed the idea.

Preen said that in October or November he will supplement current aerial surveys of dugongs with the attachment of the 10-foot tethers carrying radio transmitters to two dugongs.

Radio signals would then be picked up by the Argus satellite of the National Oceanic and Atmospheric Administration and be sent back to Saudi Arabia for analysis.

Preen said in a telephone interview from Dhahran, Saudi Arabia, that the transmitting system was tested in Indonesia on captured dugongs, which are found in many parts of the Indian Ocean.

Very Shy Mammal

“We are not going to hunt the two dugongs,” Preen said. “With the assistance of local fishermen, we shall try to net and restrain them and I will attach the transmitter in less than two minutes. It is a very live operation and extreme care will be taken not to harm the sea mammal.”

Biologists know little about the daily habits of dugongs. They spend two to five minutes underwater to graze on sea grass, coming up for two or three seconds for air.

They range from Madagascar off southeast Africa, around the Indian Ocean’s rim to Australia.

“Very little work has been done on the dugongs,” Preen said. “The animal is difficult to work on, and very shy. Also, there are not many places with shallow and clear water like parts of the gulf where we can carry out studies on them.

Dugongs Hunted

“They are very secretive animals. No one thought we’d find any after the Nowruz oil spill. But it seems if you really look and look properly, you find them. I sighted a herd of up to 700 between Bahrain and Qatar.”

Aside from pollution of coastal areas, human activities have threatened the dugongs, especially by advanced methods of hunting.

“Their range is probably discontinuous now,” Preen went on. “This is due to population pressures and technologically advanced hunting methods. Now so many traditional societies use gill nets, rifles and outboard motors.”

Dispersed Along the Shore

The animals spotted last March were probably gathered in a large herd because the water was warm and sea grasses were plentiful in that area, Preen said. The rest of the gulf was still cold from the winter, and only two other dugongs--one found dead on the shore--were spotted anywhere else along the Saudi coastline.

The dugongs evidently dispersed along the gulf’s western shore a few weeks later when the water in the rest of the area warmed up, Preen said.

The radio transmitters may tell the scientists how far the dugongs swim in a day or a week. The tether carrying the transmitter is designed to fall off after about three months, Preen said.

Scientists will endeavor to get the gulf governments to ban fishing of the dugong and disruption of food supplies by reclamation. The Nowruz oil spill was stopped two years ago.