Strange whale trend on Aussie coast during migration: 'Really different from last year'

Exclusive: Not only are the whales migrating earlier, their behaviour has changed. And they even look different.

Two underwater pictures showing a diver and a humpback whale.
Rather than roaring past to get to the Great Barrier Reef, some whales are stopping around northern NSW to play. Source: @tweedgoldcoastdivecharters

Something strange is happening along the coast of Australia. The annual humpback whale migration has occurred. But the timing is out, and the animals are behaving differently.

And there’s another thing — some look completely different. Several have been photographed with deep white lines criss-crossing on their backs.

Yahoo News first became aware of the scope of the change after speaking with a dive tour operator who saw an emaciated whale on the north coast of NSW covered in sea lice.

"Normally when whales come past they're steaming by at four to six knots on their way to their [Great Barrier Reef] playground.

"But this year the water has been warmer here and we've had whales stopping to play — just hitting these warmer waters and just chilling. It's like they're saying its warm enough here, we don't have to go any further," David Jaeger said.

But he's not the only ones watching the situation unfold, a group of international experts are also on the case.

Related: Disbelief as Australia smashes 400-year-old record

A group of boys watching a whale breaching from a boat.
While tourists probably haven't noticed anything strange, experts are witnessing massive behavioural changes. Source: @tweedgoldcoastdivecharters

Griffith University whale researcher Dr Olaf Meynecke is a member of the Whales and Climate — Humpback Whale Research Program. And he doesn’t think most people are aware of the scale of the issue.

He suspects the unavailability of the right kinds of food, climate change, and the ongoing shift between El Niño and La Niña could all be contributing to the problem.

“If members of the public are lucky enough to see whales from the shore or go on a whale watching trip, they don’t really see the differences between years,” Meynecke told Yahoo News.

“Because we’re doing daily observations from 130 to 135 days throughout the season, we pick up on trends. And this year is really different from last year.”

Related: Overwhelming discovery off Heron Island: 'Never imagined this would happen'

The whale migration has been shifting since monitoring began 13 years ago and 2024 is different again. Whales were first seen heading north on northern NSW and southern Queensland two to three weeks later than usual. They then spent less time on the Great Barrier Reef, and began migrating south early.

Meynecke's team has noticed dozens of humpbacks were sporting what he describes as “really interesting skin conditions”. You can watch a video showing one example of the problem below.

“They do not look normal. Some have these openings that are all white and look gooey. And at the end of the season, we’re seeing others with this condition where under the dorsal fin a blood red wound appears,” Meynecke said.

“It seems to be an indicator of stress. The skin is the mirror of the soul. And they might not have enough food or the water temperature is too warm and it allows a higher number of viruses or bacteria to grow on their skin.”

He has also seen some whales undergoing intensive skin shedding which is believed to be linked to warmer water.

"We normally see some shedding. But we are seeing big chunks of skin coming off them," he said. "It will be interesting to see how they recover."

A whale with a cut below its dorsal fin.
Whales have been spotted with severe splits under their dorsal fins. Source: Whales and Climate - Humpback Whale Research Program

Last summer Antarctica experienced record summer heat levels and this could have triggered changes in behaviour including lowering the number of calves born this year. And that's resulted in less whales being close to shore.

“We do actually see a two to three year pattern of calving rates. And because we had a lot of calves last year, it's not entirely surprising that there's lower numbers,” he said.

“But there’s a very stark difference — it’s the opposite of what we saw last year.”

Background: A whale with white criss-crossing marks on its back. Inset: A whale with peeling skin.
Several whales have been spotted with strange markings and flaking fins. Source: Jodie Lowe/Whales and Climate - Humpback Whale Research Program

In 2023 there was a record number of humpback whale calf strandings, and despite the number of births being lower this year, occurrences have remained high.

While a dozen or so deaths may not seem high when you consider 35,000 whales are migrating up both the east and west coast, the strandings are just some of the whales believed to be perishing. And many of the deaths are believed to be caused by entanglement with fishing gear.

“There are a high number of calves that would die at sea and disappear, but we only see strandings in very rare occasions,” Meynecke said.

“The stranding numbers give us an indication that something is going on.”

While this year’s migration is different, it is part of a “trend” of “extreme fluctuations” in how whale populations around the world are adapting to climate change.

“We’re also studying two population in South Africa and another in South America. What we see are drastic shifts in migration, higher mortality rates, but also higher calving rates,” Meynecke said.

“Everything is more extreme. But that makes sense because the weather conditions and food conditions are becoming just more unreliable.

“So they have to respond to it. It's a form of adaptation that we're seeing as a new trend, in the sense they are trying to cope with those more extreme conditions along their 10,000 kilometre migration route.”

Love Australia's weird and wonderful environment? Get our new newsletter showcasing the week’s best stories.