- Giant no-show comes as South Australia continues to grapple with one of the most severe harmful algal blooms Australia has recorded
- Evidence that the ocean is changing in ways we don't yet fully understand
- Much more investment needed to protect our marine wildlife and habitats
- AMCS urges Australian and South Australian Governments to take immediate, coordinated action to protect marine resilience.
Every winter, up to a quarter million giant cuttlefish gather in the shallow waters off Whyalla for one of the ocean's most extraordinary natural spectacles, a frenetic, colourful mating aggregation found nowhere else on Earth. This year, divers report finding the reefs largely empty.
The South Australian Department of Primary Industries and Regions has today confirmed that surveys conducted revealed population estimates of less than 2,000, with some surveys showing zero cuttlefish.
The scale of the no-show is deeply concerning, and comes when South Australia's marine environment is under significant pressure from possibly the most severe harmful algal bloom (HAB) recorded in the country.
The recent HAB is the most likely driver behind 2026's plummeting cuttlefish population. Species such as giant cuttlefish - which depend on healthy shallow bays for their once-in-a-lifetime opportunity to reproduce - are particularly vulnerable to these kinds of pressures.
Australian diver and filmmaker Woody Spark, of Grumpy Turtle Films, spent two weeks in June in the water at Whyalla documenting the event.
"I was there in Whyalla, when hundreds of thousands of cuttlefish normally gather to breed," he said. "It's one of the most incredible natural spectacles on Earth, but this year there was next to nothing. I spent 15 hours in the water that first week, diving empty, barren reefs, looking in every crack and crevice, and in that time I saw just 3 cuttlefish.
"I've filmed the place many times before, and I've never seen anything like this.
"It was incredibly confronting to visit Whyalla and to see so few of the spectacular giant cuttlefish that are normally there – but to see this absence backed up by data PIRSA's report is truly devastating."
AMCS Wildlife and Habitat Campaign Manager Jaimi Webster said: "The missing cuttlefish are a powerful reminder of how much is still unknown about the pressures facing our oceans, and how urgently that needs to change.
"What we've heard from divers in Whyalla is heartbreaking. This is one of the most spectacular natural events anywhere in the world, and this year it simply hasn't happened.
"Our oceans are changing in ways we can't always predict or fully understand, and that's exactly why we need to do everything we can to protect them and build their resilience. Whether it's giant cuttlefish in Whyalla or the harmful algal bloom devastating marine life elsewhere in South Australia, we are seeing more and more signs of ecosystem decline along our coasts.
"We call on the Australian and South Australian governments to take immediate, coordinated actions to protect our marine life. We urge them to immediately disclose all historic, current and projected funding allocated to long-term monitoring of our marine life and habitats and to act now to reduce threats and build the resilience of these important habitats"
About the Australian Marine Conservation Society (AMCS):
The Australian Marine Conservation Society (AMCS) is Australia's leading voice for ocean conservation. As an independent charity, we have been protecting our precious marine life and habitats since 1965.
We are a passionate community of scientists, educators, and advocates dedicated to safeguarding Australia's oceans. Our work has helped establish vital marine reserves, protect endangered species like the Australian sea lion, stop super trawlers and lead efforts to ban whaling.
From the Great Barrier Reef to Ningaloo, together with our community of ocean lovers, AMCS fights for healthy oceans and marine wildlife every day.
