A dozen heavily pregnant endangered sharks have been spotted off the northern coast of Australia.
Divers from the Department of Environment and Science (DES) captured footage of the grey nurse sharks circling around Wolf Rock in Queensland.
Senior conservation officer with the DES, Dr Carley Kilpatrick, said marine rangers believed the 12 spotted could be part of a colony of more than 50 pregnant females at Wolf Rock.
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With fewer than 2000 individual sharks estimated in the east coast colony, the species has been long endangered, but with increasing birth rates, the population is on the rise.
The average gestation period for the sharks is 12 months, and with warmer weather soon arriving, the females will soon be on the move to NSW's coastline in order to begin the birthing season.
"A female grey nurse reaches sexual maturity around nine to 10 years and has a gestation period of around twelve months," Dr Kilpatrick said.
"She will give birth to two pups every two to three years, so the grey nurse shark population is slow growing," she said.
The males, meanwhile, will remain behind in Queensland awaiting the return of the females before the next breeding season.
"Wolf Rock in the Great Sandy Marine Park is the only known gestation site for the east coast grey nurse shark population," said Dr Kilpatrick.
There are four designated grey nurse shark areas in Queensland, three in the Moreton Bay Marine Park and Wolf Rock in the Great Sandy Marine Park.
