A new DNA study has revealed koalas in Port Stephens have limited gene flow, due to their isolated habitats.
The research was commissioned by the World Wide Fund for Nature-Australia (WWF), as part of its campaign to double the koala population in eastern Australia by 2050.
The report disclosed two main koala genetic clusters in the Port Stephens area, one in the Tilligerry and Tomaree Peninsula, and another in the Karuah, Ferodale and Balickera region.
WWF Australia’s head of healthy land and seascapes Darren Grover said the wildlife organisation was “concerned” about the limited gene flow among the Port Stephens koalas.
“They can lose genetic diversity and become less able to adapt to climate change or fight off new diseases,” he explained.
“Habitat fragmentation, which impedes gene flow, is a major problem for koalas and other species.
“That’s why a major focus of Koalas Forever is to protect existing habitat, regenerate cleared forests, and to plant tree corridors to reconnect isolated populations.”
Researchers collected koala feces on three occasions, in November 2018, July 2019 and May 2020.
The study used detection dogs – Taz and Missy – provided by OWAD Environment, to locate koala scat.
The droppings would then be analysed for DNA by scientists at the Federation University Australia.
The report outlined the two genetic clusters were once linked, however now the peninsula koalas are now “significantly different” from their inland brethren.
It suggested the decline in genetic diversity among peninsula koalas may be due to difficulties for koalas to migrate outside this area.
Mr Grover added more research was needed in order to compare different koala populations, and welcomed $1 million in state and federal government funding to map the genes of 400 koalas.
“Understanding koala population structure is essential to effectively protect the species,” he said.
“Ultimately the most important action needed is to safeguard existing habitat, regenerate cleared forests and plant corridors to reconnect isolated groups.”