There’s hope across a South Australian coastal town after holidaymakers cancelled their trips when a natural annual event didn’t occur as expected this winter.
Every June, between 75,000 and 150,000 brightly coloured giant cuttlefish assemble to mate in one place — the shallows of Whyalla, in South Australia’s Spencer Gulf.
Their bright displays and huge numbers attract thousands of people, bringing in close to $10 million for the town’s Cuttlefest festival alone.
But so far, only a few dozen have been documented, possibly due to the toxic algal bloom that has killed upwards of 90,000 marine creatures, from 390 species.
Over the weekend, local tour guide Steve Storic saw something through his boat’s glass bottom that has left him “super excited”.
Have you been affected by the algal bloom? Contact newsroomau@yahoonews.com
“I saw a really good arrival yesterday, it was a pack of around 50,” the Spencer Gulf Adventures owner told Yahoo News.
Whyalla is the only place in the world where tens of thousands of giant cuttlefish congregate to mate.
(Getty)
“I’m absolutely buzzing, and I’d really like to keep some hope and faith.”
“People have been cancelling flights, accommodation, and holidays, and everyone is feeling the pinch in Whyalla, and I’d love to be able to say, We’re back on.”
Storic doesn’t ordinarily start seeing cuttlefish amass until the blue swimmer crabs have gone.
They’ve only just started to disappear, and so he’s hoping the cuttlefish might just be late.
“Things could be right in two weeks’ time,” he said.
Three events linked to the cuttlefish disappearing
Staff at the Whyalla Dive Shop and Cutty Tours are less hopeful – on Friday, they declared the season had been “cancelled”.
And they believe the remaining animals should be left alone, so they can complete their breeding cycle without interference from human activity.
Whyalla Dive Shop owner Manny Katz said his crews have only spotted a couple of dozen cuttlefish, and it’s clearly the “smallest population by this time of the year” on record.
“This season is a write-off,” he told Yahoo News.
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Katz suspects the mass die-off of marine life caused by the algal bloom is to blame for the collapse.
But he can’t be sure, because historically there has been very little funding for research or monitoring of the species.
Garfish lie rotting along the South Australian coast due to the algal bloom last year, which has turned waters green.
(Stefan Andrews, courtesy Great Southern Reef Foundation)
He doubts cuttlefish numbers will rebound next year, and it will be “a bust” because he fears there still won’t be enough food for them to eat.
“If baseline food species get wiped out, then it trickles up,” he said.
The 2025/2026 algal bloom was the worst in South Australia’s history, and the bad news is that several of the environmental conditions that triggered it could persist, primarily because of climate change.
The Karenia mikimotoi and Karenia cristata thrived because of three main factors:
Warmer than average sea temperatures.
Nutrients from farms along the Murray-Darling River flushed into the ocean due to flooding.
The state government has established a $3.8 million Office for Algal Bloom Research to investigate techniques to try and mitigate the impact of future events.
19th-century decision still impacting South Australia
On top of climate change impacts, the state’s waters also struggle to naturally process pollutants due to a near-extinction event in the 19th century.
Around 98 per cent of the Australian southern coast’s native oyster beds were plundered — their meat was used as a cheap food source, and their shells for grout — and their loss has crippled the ocean’s ability to filter out pollutants.
Katz is part of a project to restore them, but he warns that there are a “bunch of different problems” stifling the giant cuttlefish’s rebound.
“In Whyalla, we’ve got the steel works and an oil refinery, and the cuttlefish aggregation site sits between them,” he said.
“But there’s so much industry between farming, fishing and mining that happens all around this state.
Cuttlefish decline a ‘byproduct of progress’
Storic won’t know whether the cuttlefish are late or have failed to show up until the end of the week.
The conditions are expected to be choppy, and so he will spend the week “sitting tight and being patient”.
“It could be the story of the season,” he said.
The toxic algae bloom in South Australia killed hundreds of different species.
(hozie.r/TikTok)
Katz is confident this year is a “bust”, but he’s confident the numbers will eventually rebound.
“They are resilient organisms, and they have a propensity for life,” he said.
But to ensure the cuttlefish aren’t just wiped out by another algal bloom, he said more research and monitoring are needed to understand how industry is impacting them and the wider ecosystem.
“We’re watching our oceans dying in front of us, and this is the byproduct of the progress of humanity,” he said.
“There’s a lot that needs to be done.”
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