Playing tag no game for Moreton Bay's dugongs

Playing tag with dugongs in Moreton Bay has convinced University of Queensland researcher Dr Janet Lanyon that a world-first mark and recapture program will give a new insight into the mysterious mammal.

The successful tagging and release of 54 dugongs living and feeding in the Bay last summer was the first stage of a long-term project to study the dynamics of the local population.

Dr Lanyon said the recent apparent declines in dugong populations globally and along the eastern Australian coast highlighted the urgent need for reliable information about population structure, trends and life histories.

Moreton Bay's estimated 850 dugongs are the southern-most population on the east Australian coast.

Dr Lanyon said the program would provide information on trends in population size, distribution and age structure, adult survival, reproductive status of individuals, recruitment rates, intra-population genetics, mating strategies, social behaviour and general health.

Moreton Bay is an ideal environment because it has relatively clear water, a large population in a concentrated area and dugongs used to boating traffic.

A rodeo technique similar to that used in turtle research has been perfected for the program by researchers and volunteers from the UQ Zoology and Entomology Department.

"For each dugong, body size measurements were recorded," Dr Lanyon said. "Tags we applied included a long term dorsal PIT tag, a titanium turtle tag, fluke notch and temporary paint stick mark. We also collected small tissue samples for genetic and toxicological analysis."

Dr Lanyon said the program could not have been carried out this year without the Sea World Research and Rescue Foundation, which contributed $45,000 worth of in-kind support, including boats and personnel.

"We have also had financial support from the Winifred Scott Foundation, and Consolidated Rutile has provided us with funds for microchip (PIT) tags for the dugongs," she said.

Dr Lanyon is seeking funding to recommence the program in October. "It is ongoing and a full tagging program will continue through the summer months each year, as long as we can raise annual funding of $100,000," she said.

Dr Lanyon's collaborators on the project are Dr John Kirkwood of the Department of Primary Industries Southern Fisheries Centre and Dr Rob Slade of the Southern Cross Institute for Whale Research, and her research assistant is Helen Sneath.

For more information, contact Dr Janet Lanyon on (telephone 07 3374 1334) or Brad Turner at UQ Communications (telephone 07 3365 2659).