The Australian humpback whale population has recovered from near-extinction linked to hunting, but new Queensland research warns that numbers could soon fall again due to the effects of climate change.

Key points: Humpback whale species has recovered rapidly since commercial whaling ended in 1962, averaging a 10.9pc increase per year

Humpback whale species has recovered rapidly since commercial whaling ended in 1962, averaging a 10.9pc increase per year Researchers remain worried the whale population may be overshooting the carrying capacity of the environment to maintain its numbers

Researchers remain worried the whale population may be overshooting the carrying capacity of the environment to maintain its numbers If there was going to be a whale population crash, researchers say the modelling suggests it will be soon

The University of Queensland (UQ) study monitored humpback whales migrating past North Stradbroke Island off Brisbane on the southern Queensland coast, over a 12-year period.

Associate Professor Michael Noad said the species had recovered rapidly since commercial whaling ended in 1962, averaging a 10.9 per cent increase per year.

"The good news is that the whales have recovered, but the bad news is that the whales don't seem to have realised that," he said.

"Australian humpback whales were hunted to very, very low numbers — almost completely wiped out by the early 1960s — but since we've started [taking] surveys, the population has essentially been doubling every seven years or so.

"The last survey in 2015 found that the population has essentially recovered back to our best guess of the population prior to whaling in the 1950s, reaching an estimated 25,000 whales."

Humpback whales have bounced back, but a new challenge looms. ( ABC News: Shelley Lloyd )

Population boom may lead to bust

Despite the good news, Dr Noad feared the species still faced many threats.

"We don't really know what is going to happen in the future, but we worry that the population may in fact be overshooting the carrying capacity of the environment to maintain that population, so we might see a spike in the population followed by a crash," he said.

The whales are also threatened by climate change and its impact on Antarctic krill. ( ABC News: Shelley Lloyd )

He said if there was going to be a crash, the modelling suggested it would be soon.

"The thing that's most likely to have an impact on these whales is them starting to run out of krill in the Antarctic … and we predict that to happen somewhere between 2021 and 2026," he said.

"On one hand they're recovering quickly, but these whales are also threatened by climate change and its impact on Antarctic krill, their main food source."

The east coast whale watching industry is worth more than $100 million. ( ABC News: Shelley Lloyd )

'It's a bit like counting sheep'

The most recent data was collected in 2015 by scientists observing whales from a platform at Point Lookout on North Stradbroke Island off Brisbane.

"This is a fantastic place to monitor the whales because they come very close to the headland," Dr Noad said.

"We know that about 80 per cent of the population passes within 5 kilometres of the headland, so they're easy to see — it's a bit like counting sheep as they go through a gate."

The data was collected by scientists observing whales from Point Lookout on North Stradbroke Island. ( ABC News: Shelley Lloyd )

If there was a population crash, it could have several consequences for Queensland.

"There'll certainly be fewer whales and those whales might be struggling — you might be seeing sick calves not in good condition and that could have an impact on the east coast whale watching industry, which is worth more than $100 million to the economy," Dr Noad said.

"We are very likely to see an increase in the number of strandings as well — possibly sick whales beaching themselves, and also whales that die at sea will represent a shipping hazard."

The research has been published in the scientific journal Population Ecology.