One of the last colonies of dugongs under threat from natural gas plant

A colony of rare dugongs, or sea cows, is under threat because of a natural gas plant being built on the harbour at Darwin in northern Australia, marine scientists have warned.

A colony of rare dugongs, or sea cows, is under threat because of a natural gas plant being built on the harbour at Darwin in northern Australia, marine scientists have warned.

The dugong is an endangered species whose numbers are in sharp decline worldwide. Australia has the world's largest remaining population, including a sizeable colony in Darwin harbour, which is home to abundant marine life, including man-eating saltwater crocodiles.

The dugong, a herbivorous mammal the size of a small whale, is noted for its shyness and grace of movement. Sailors supposedly mistook the creatures for mermaids. Fishermen say they cry piteously, like a baby, when injured.

Environmentalists fear the noise and activity generated by large gas tankers will drive them out of the harbour. "The dugongs won't last two minutes," said Ray Taylor, a member of Save Darwin Harbour Group, a lobby organisation formed by local residents.

Construction has just begun on the plant, which will process liquefied natural gas piped in from fields below the Timor Sea, 300 miles north of Darwin. The project follows an agreement signed by Australia and East Timor to share the resources of the Timor Sea. An additional 48 ships will use the harbour when the plant, constructed by Phillips Petroleum, begins operating in 2006. That number will triple when it reaches full capacity.

Dugong numbers have fallen steeply in recent years, their habitats eroded by coastal development and their food source - seagrass - destroyed by pollution. Many animals are caught accidentally in fishermen's nets. In the Torres Strait, between northern Australia and Papua New Guinea, they are legally hunted by indigenous people for food.

Dr Scott Whiting, a marine biologist at Northern Territory University, believes there will be an exodus from the harbour. "Probably the major impact will be habitat loss," he said. "The dugongs will move away from their habitat because of noise and activity."

Blair Murphy, the Darwin area manager for Phillips Petroleum, said the impact on the dugongs would be minimal. He said they were more likely to be hit by small boats than by slow-moving tankers. "We will be working with dugong specialists to monitor any impact on habitat," he said. "There could be some movement from one place to another, but they do move up and down the coast within hundreds of kilometres. We are waiting for more detailed studies."