Fishing for clues on dugong numbers

Crystal Ja, Brisbane Times 22 May 08;

Researchers hope a ground-breaking Australian study on wild dugongs will help shed light on why their numbers continue to dwindle.

The joint project, conducted by the University of Queensland (UQ) and Sea World, allows scientists to examine live dugongs out of the water in a first for Australian biologists.

The five-day fact-finding mission at Moreton Bay, home to one of Australia's most dense dugong populations, has so far seen eight dugongs successfully captured and assessed.

After being tackled in the water by a team of up to four people, the animals are taken onboard a research boat to have blood, urine and even tear samples collected.

The creatures, also known affectionately as "sea cows", are kept shaded and wet for up to 40 minutes before being released back into the water.

Sea World's Wendy Blanchard said there were about 100,000 dugongs living in the wild, but they were increasingly affected by humans, and global dugong numbers were falling.

"They're vulnerable because they like living in shallow coastal water," she said.

She said many get caught in fishing nets, while a smaller proportion get hit by boats.

UQ dugong research team leader Janet Lanyon said the study would help determine why large numbers of dugongs were dying along Australia's east coast.

"There are still large numbers of dugongs dying along the Queensland coast and we have no idea as to why they're dying," she said.

"We're not sure if there are some diseases in the dugong population, or if there's some other health problem, so this project is giving us some baseline data on the health of the animal."

In a positive sign for the Moreton Bay dugong population, all the females caught so far have been pregnant, proving the mammals were doing particularly well in that environment, Dr Lanyon said.

Sea World director of marine sciences Trevor Long said maintaining dugong numbers remained one of the park's key priorities.

UQ has been running health checks on dugongs since 1996.

AAP