Rising sea levels in the Torres Strait have led to the discovery of an Indigenous burial site and a murder mystery that archaeologists believe pre-dates colonial settlement in Australia.
As an unusually high tide receded from the shores of Muralug Island in January, it unearthed skeletal remains, the age of which archaeologists are trying to confirm through carbon dating.
Muralug, or Prince of Wales Island, is the ancestral home of Enid Tom, an elder of the Kaurareg people.
"This is the first time for us that a burial site has come up, but there'll be many more of course," Ms Tom said.
An archaeological team, led by the University of Queensland's Michael Westaway, began excavating the site on Long Beach in May.
Over two days, they carefully uncovered a complete skeleton of a First Nations woman aged in her mid-to-late 20s.
Dr Westaway said there was evidence she had been killed.
"This young woman had some fairly terrible trauma in the lower abdomen, in the lumbar vertebrae," he said.
"We think she'd been speared through the stomach."
Dr Westaway said the woman had been carefully laid into the grave with her left hand placed over the apparent site of the injury.
"This wasn't someone who was just murdered and abandoned. It was someone who was killed and then carefully interred by the people that cared for her," he said.
The ABC is not publishing photographs of the skeletal remains out of respect for the Kaurareg people.
'Thank you, I'm safe'
For Ms Tom, the discovery means the Kaurareg people can learn more about their history and protect the woman's remains and spirit from the rising sea.
She said it was important to remain by her ancestor's side throughout the excavation process.
"I spoke to her during all this time, I was talking language and telling her we were going to put her in a safe place," Ms Tom said.
She described a kookaburra watching on from a nearby tree on the dunes, while a swarm of butterflies flew down to the burial site.
"The kookaburra is a sacred bird to us and as soon as we started digging her up, the kookaburra sat there and just stared at us and wouldn't go away," she said.
"[The butterflies] swooped down onto her, came up in a group and then went down again, so for us it was very spiritual.
"I believe that was her saying, 'Thank you, I know I'm safe now'."
After the excavation, the skeleton was laid out on bark, then wrapped and taken to a safe burial site, far from the encroaching tide.
"There was a really respectful procession where the women took her back into the closed forest and the rangers had prepared a new pit for her," Dr Westaway said.
Carbon dating
The researchers are still awaiting carbon dating results but are confident the skeleton pre-dates European settlement in Australia.
"She was buried about a metre to a metre and a half down, so I suspect she'd been buried some time ago," Dr Westaway said.
"She didn't have any evidence of modern European dental diseases ... but we won't know for sure until we get the carbon dates back, which are probably a couple of months away."
Dr Westaway said isotopes from a tooth offered to the archaeological team by the Kaurareg elders would also shed light on the woman's movements and lifestyle.
"That will also give us enough information to obtain a carbon date to provide a more reliable estimate of her antiquity," he said.
"Because the bone was so well preserved, I suspect we will be able to recover ancient DNA from this young woman and look at her connections to community there today."
Using ground-penetrating radar near the exposed burial site, the archaeological team found four other potential interments in the immediate area.
Ms Tom said she was now concerned other burial sites would be disturbed by the elements on Muralug.
"It's the biggest island in the Torres Strait and there's a lot of beaches," she said.
"Our people travelled around the island in different seasons hunting for different foods, so there's a lot of campsites on the beaches where people would have died."
Coastal erosion and climate change
Coastal erosion and seawater inundation have long been an issue in the Torres Strait but have taken on a new urgency.
In its preliminary report, the UQ team noted record-high sea levels observed at Thursday Island in February and an increase of 10 centimetres since monitoring began in 2015.
The report pointed to "a combination of king tides and/or extreme events, plus an increased sea level that cause new erosion ... that allows waves to reach higher and more inland areas".
Queensland's Minister for Aboriginal and Torres Strait Islander Partnerships, Craig Crawford, said climate change was a major threat to sites of cultural significance in the Torres Strait.
"Anyone who's been there will see how low-lying many of those islands are and just a simple rise of a metre or metre and a half of the tide can make a significant impact," Mr Crawford said.
He said a Department of Environment grant had been awarded to the Kaurareg Land and Sea Rangers to identify and protect other beach erosion sites in the region.
"We need to make sure we can protect these sites and know where they are, but it also needs to be done in a very culturally appropriate way," he said.
