Comparing whale populations year-on-year with precision is difficult because of a lack of funding for research, Pirotta said. While citizen scientists work hard to plug the gaps, they are often short of resources.

Meanwhile, a white whale sighted off the Queensland coast this week may be the legendary Migaloo, an albino humpback whale that was thought missing, and possibly dead, since 2020.

Migaloo became the leading celebrity in the whale world after it was first sighted in 1991.

Its speedy annual migrations up and down the east coast of Australia - Migaloo averages over 125 kilometres a day, a fair clip for a Humpback in open water - have become a highlight for scientists and whale watchers.

Migaloo has been declared dead twice, but in each instance it has been a case of mistaken identity.

Footage taken from a tourist aircraft flying near the Whitsunday Islands last week showed a white humpback swimming at the surface.

Pirotta said white whales are extremely rare - only a handful of individuals have been identified worldwide - but it has not yet been confirmed whether last week’s sighting was Migaloo or another whale.

The Morning Edition newsletter is our guide to the day’s most important and interesting stories, analysis and insights. Sign up here.