The people of Australia’s east coast are catch a first glimpse earlier than expected to rape humpback whales as they migrate north, and scientists say the reason is a conservation success story.
Whale watchers were treated to a spectacular sight in Sydney on Monday as two humpback whales sprang from their boat’s water meters. Dr Wally Franklin, director of the Oceania project, said sightings had also been reported off Merimbula, Byron Bay, Tweed Heads, the Gold Coast and Hervey Bay, as the whales traveled north from Antarctica to the Great Barrier Reef.
Professor Mike Noad, director of the Center for Marine Studies at the University of Queensland, said the number of sightings at the start of the season, which usually peaks in late June and July, is due to the explosion of the eastern Australian population of humpback whales. during a remarkable period of recovery.
In the early 1960s, when commercial whaling was banned in the area, Noad said it was estimated that only around 300 of eastern Australia’s humpback whales remained. Sixty years later, he suspects the population is now around 40,000.
“About 20 years ago we had the first whale or two to pass at Easter, but there were about an eighth of the number of whales there are now,” he said. “So one or two at Easter now becomes 16 or 30…so every year it’s probably the same migration.” It’s just that there are more whales in the population.
“It’s a great success. They went down to about 1% of the original population – 99% were wiped out. That’s how close they came to being completely wiped out.
“All we had to do was stop killing them, we didn’t do much but leave them alone…and they bounced back themselves in a very healthy way.”
Noad said the last major whale population survey was conducted in 2015, so the estimated whale population is a “best estimate.” The surveys had since been funded by the federal government due to the whales returning to a healthy population level.
But Noad said there was a need to continue polling the population to understand how the whales are being affected by the climate crisis, pollution, underwater noise and potential collisions caused by boat traffic.
In February, humpback whales were removed from the endangered species list, which angered a number of scientists due to the threats the species continues to face.
“We have no idea if [the population level] is sustainable, we have no idea … if they will increase or if they could collapse if they exceed their food supply,” he said.
Franklin said the whale population increased by 10% every year between the 1990s and 2015.
He said the drastic growth in whale populations had taken researchers by surprise, with scientists working in the northern hemisphere who studied whale populations previously thought that the maximum annual growth rate for whales was 8%.
Franklin suspects the eastern Australian whale population has exceeded that expectation because the Great Barrier Reef is “the perfect place for a breeding ground.” He said researchers have found evidence that whales from other parts of the Pacific have migrated to eastern Australia.
“The benefit is that whale watchers along the New South Wales and Queensland coast can start seeing whales earlier, and they will see them for longer.”