A new report from James Cook University's TropWATER reveals a thriving dugong population in far northern Queensland, stretching from Cape York to Mission Beach – a stark contrast to concerning dugong numbers in southern Queensland.
The survey results show the far northern area is home to about 7,000 dugongs, almost double the number reported in central and southern Queensland.
Released this week, the 2023 Dugong Aerial Survey: Mission Beach to Cape York report completes the Queensland coastal surveys, with the Mission Beach to Moreton Bay report released last year which highlighted concerns about dugong populations in the southern regions.
The aerial surveys have been conducted every five years over the past 30 years, monitoring dugong populations along Queensland's coast and providing insights into areas where they were more or less abundant.
Over 17 years, the dugong population in the far northern Queensland area has grown at approximately 2% per year, indicating that the dugongs in this region are in good condition.
Lead dugong researcher, TropWATER's Dr Chris Cleguer said it was encouraging to see dugong numbers and their calves stable in the far north.
"Our results show dugong populations in the far north are thriving overall. This is great news, and we hope this trend will continue in future monitoring surveys," he said.
"This trend is notably different from what we observed in our last surveys in central Queensland and the southern section of the Great Barrier Reef – especially the concerning numbers from the Whitsundays to Bundaberg."
In the far north, dugong abundance hotspots remains consistent north of Cape Flattery and Cape Melville, and in sheltered bays like Lloyd Bay, Temple Bay, and Shelburne Bay.
Dr Cleguer said that while scientists know the main human-induced threats to dugongs, there is a lack of location-specific data to understand local declines.
"We know healthy seagrass meadows are essential for dugong survival. It is their main food source with these sea cows eating around 40 kilograms of seagrass daily, depending on their body size," he said.
"So, we need to know more about seagrass health across Queensland and how this affects dugongs. This includes offshore seagrass, which we know so little about.
"This would help us understand and even predict when dugong population could change – giving managers the best opportunities to conserve this iconic species."
The JCU TropWATER team is tracking dugong movements and behaviour, assessing their health through drone-based body condition surveys, and taking blood samples of captured and tagged animals.
"We also use population genomics to identify dugong populations and their connectivity across northern Australia, and we are equipping Indigenous rangers with drone survey skills for fine-scale monitoring," he said.
"These projects are critical in giving us the right data to help manage these marine mammals."
This project is jointly funded by the partnership between the Australian Government's Reef Trust and the Great Barrier Reef Foundation, the Department of Climate Change, Energy, the Environment and the Australian Government under the National Environmental Science Program.
Great Barrier Reef Foundation Integrated Monitoring and Reporting Director Charlie Morgan said the Great Barrier Reef supports one of the world's largest dugong populations.
"This landmark dugong census has been instrumental in advancing our understanding of dugong populations across the entire Great Barrier Reef.
"The data collected from this project and our other comprehensive monitoring programs for reef fish, sea cucumbers, inshore dolphins and seabirds will inform critical conservation efforts and management decisions to help protect these iconic species from the growing impacts of climate change."
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