91�ȱ�

Humpback whales have been removed from Australia's threatened species list 60 years after the practice of whaling, which is when the mammals are hunted for food and other products like oil, largely came to an end.

Humpback whales, which were once on the brink of extinction, have seen a remarkable improvement in their numbers.

"At the height of the global whaling industry there were as few as 1500 humpback whales in Australian waters, today that population is believed to be as many as 40,000 individuals and growing," said Australia's environment minister Sussan Ley.

It suggests efforts to look after the mammals have been largely successful. However, the Australian government says measures will still remain in place to protect the mammals.

"This is not about removing safeguards for humpbacks, which are still a protected migratory species, but it is a recognition of the success of the outstanding conservation efforts that are in place," Minister Ley said.

"Our removal of the humpback from the threatened species list is based on science and sends a clear signal about what can be achieved through coordinated action. It is a message of hope for the welfare of a number of species."

Despite the positive change to humpback whale numbers, conservationist groups supporting the protection of the animals have raised concerns about the impact climate change could have on humpback whale numbers as the world's oceans get warmer.

It's believed changes to ocean temperatures could have a significant impact on krill populations in Antarctica. Krill are one of the main food sources humpbacks rely on.

The whales also face problems caused by plastic pollution, with the mammals getting trapped in larger plastic items and swallowing smaller objects.