Silt a threat to dugongs
BIOLOGISTS from the University of Queensland have teamed up with Sea World and Taronga Western Plains Zoo to assess the health and reproductive status of wild dugongs in Hervey Bay.
The research team started work here yesterday after completing a similar project in Moreton Bay.
Leader of the UQ Dugong Research Team Dr Janet Lanyon said the floods had placed a huge question mark over the health of the dugongs along the entire Queensland coast as the silt and sediment had the potential to kill their only food source, seagrass.
“This trip is extremely important to give us an indication of how the Hervey Bay dugongs have fared following the recent flood disaster,” he said.
“We know that following the 1991 disaster which included two floods and a cyclone in a short space of time, we saw the deaths of at least 99 dugongs as a result of a massive seagrass die-off.
“In almost every case of the 99 recorded dugongs which washed up along the Queensland and New South Wales coasts in 1991 there was evidence of starvation.
“During this period it is estimated that the Hervey Bay dugong population fell from approximately 1700 animals to as few as a couple of hundred.”
The aim of the research trip will be to determine both the health and reproductive status of dugongs. Reproductive status of individuals is one of the most important factors for estimating reproductive capacity and health of the population.
Dr Lanyon said field biologists would this week be sampling a selection of dugongs, representative of both sexes and from adult, sub-adult and juvenile size classes.
Sea World Director of Marine Sciences Trevor Long said the sampling involved lifting wild dugongs out of the water and on board Sea World's research vessel to take a comprehensive series of blood and other tissue samples to measure reproductive hormones, collect semen from adult males and conduct abdominal ultrasounds to confirm pregnancy of females.
Mr Long said a specially designed stretcher was used to cradle the animals from the water on to the deck of research vessel Sea World One.
“This is the fourth year in which Sea World and UQ have teamed up to conduct this study which allows us to capture data to help establish baseline clinical blood parameters for the species and monitor annual reproductive capacity,” he said.
“These baseline parameters can then be used to assess the health of dugongs in wild populations further up the Queensland coast and elsewhere, and also for comparison with dugongs in human care.”
Mr Long said the dugong was a major conservation priority for Sea World.
“The Sea World Research and Rescue Foundation's work in past years has resulted in the rescue and rehabilitation of dugongs Pig and Wuru, who now reside at Sydney Aquarium.
“It's also great to be conducting this research around World Environment Day which is a global day for positive environmental action.”
The plan is to capture up to 20 dugongs in Hervey Bay over five days with a team of 16 skilled personnel taking approximately 30-40 minutes to sample each animal.