The National Parks and Wildlife Service in New South Wales state said a large number of whales with newborn calves were set to swim past Sydney towards the cooler waters of Antarctica between September and November.

More than 1,000 whales were spotted passing Sydney's Cape Solander in June alone as the marine mammals made their way up to the warmer northern waters of Queensland state to breed. Volunteer whale spotters at Sydney's Botany Bay logged a 17 percent increase in whales migrating north, while whale-watching vessels were noting more calves making the trip back south. Skippers also spotted more young calves.

The numbers of humpback and southern right whales visiting waters off Australia's east coast are gradually growing back to levels not seen since the end of commercial whaling in New South Wales in the 1960s. Humpback numbers on the east coast have taken a long time to recover after being heavily hunted to very, very low levels, with southern right whales almost to the point of extinction. Good news all around!