HERVEY Bay's dugongs have fared worse than their Moreton Bay counterparts after the summer floods, a Sea World and University of Queensland survey has found.
Researchers from UQ, Sea World and Taronga Zoo spent the past two weeks catching wild dugongs to survey the health of the populations.
It was the first time the team had carried out its revolutionary capture methods in Hervey Bay, which suffered massive losses to its dugongs after the 1991 floods.
“We've been studying dugongs with UQ for many years, probably 10 years, but it was only four years ago we developed the techniques and processes to be able to lift them (dugongs) out on board and do the work,” said Sea World's director of marine sciences, Trevor Long.
“You've got to remember these are big animals and they're very sensitive animals. We've got to be very, very cognisant of their welfare and caring about our approach.”
UQ marine mammal researcher Dr Janet Lanyon said the 1991 floods showed that the Hervey Bay dugongs were more vulnerable than the Moreton Bay population because their feeding grounds were closer to the coastline.
“The seagrass beds in Hervey Bay copped the full brunt of the floods up there in 1991, and the dugong habitat was virtually lost because the seagrass beds were smothered,” she said.
“The beauty of Moreton Bay's feeding area is it's a little removed from the coast – a few kilometres offshore.”
The researchers were pleased to catch several pregnant dugongs, including a whopping 600kg female, in Moreton Bay.
“Catching pregnant females is a really good sign that the population is healthy and that they are reproducing,” Dr Lanyon said.
But as of Wednesday the researchers had not found any pregnant dugongs in Hervey Bay.
“From an observation point of view, we've seen some of the animals here have been in slightly poorer condition than those in Moreton Bay,” Mr Long said.
“We won't know any real details until we get all of the blood work back, but from a physical point of view these animals are certainly thinner.”
Mr Long said the trip would lead to a better understanding of Hervey Bay's less-studied dugongs.
“The good thing is we've got some benchmarking for future assessments,” he said.
“That's the best thing, otherwise you never know where you're at. You don't know whether they're getting better or worse.”
Mr Long said the results of blood toxicology tests, which would take several months, would reveal any impacts on the dugongs from pollutants or heavy metals washed into the bays by the floods.
Dugongs are highly migratory and are found in tropical waters from the Qld/NSW border in the east to Shark Bay in WA.
They are also known as “sea cows” because they graze on seagrass.
Dugongs are protected under the Environment Protection and Biodiversity Act of 1999.
Kat the “lonely dugong” has been living alone in the remote Cocos Keeling Islands, an Australian territory near Christmas Island, for the past nine years.