Crown-of-thorns starfish are notorious for devouring coral reefs, but surprising new research reveals these spiny predators may actually help reefs thrive when their populations are kept in check....

However, new research from the University of Sydney suggests these infamous reef destroyers may also have a surprisingly beneficial side. When their populations remain under control, crown-of-thorns starfish can help maintain healthy coral communities and support greater biodiversity. Native to Australia's Great Barrier Reef, these coral-eating starfish have caused enormous damage during population explosions. Since the 1960s, the reef has experienced four major outbreaks, occurring roughly every 15 years. Declining numbers of natural predators, including tritons and several species of reef fish, have made the Great Barrier Reef and other marine ecosystems more vulnerable to these destructive events. Scientists Discover That Coral Often Survives Starfish Attacks In a study published in Ecology and Evolution, researchers investigated what happens to coral after crown-of-thorns starfish feed on it. The team examined feeding scars and remaining living tissue at the University of Sydney's One Tree Island Research Station, located on the Great Barrier Reef. The study sites were within protected areas where healthy fish populations help keep starfish numbers under control. Unlike other parts of the reef that experience devastating outbreaks, these locations maintain relatively low populations of crown-of-thorns starfish. The results revealed an unexpected pattern. A team led by Dr. Shawna Foo...

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With the potentially catastrophic, record-smashing El Niño still peaking in the Pacific Ocean, scientists are warning of a fundamental ecological shift that would see swathes of the Great Barrier Reef become dominated by seaweed instead of coral. During El Niño events, warmer ocean waters pool in the eastern and central Pacific. However, the phenomenon also dramatically disrupts the usual monsoon troughs, low-pressure zones that bring cooling clouds and rain to the Great Barrier Reef region. This is why the worst Great Barrier Reef coral-bleaching events have coincided with past El Niños, such as the devastating reef mortality that occurred in 2024. Coral bleaching occurs when reefs turn a brilliant white after water temperatures become higher than the animals that comprise the colonies can tolerate. Heat stress leads the corals to eject the colourful algae that live within their tissues and provide them with food. This puts them at risk of starvation and death, unless waters cool quickly. Now, David Schoeman at the University of the Sunshine Coast says that ocean temperatures have increased so much that coral bleaching is occurring even during neutral and La Niña periods, which normally bring cooler weather to the reef. “We’ve had six events in...

When you swim through the azure waters of the Great Barrier Reef, there is one entity on the seafloor that’s almost impossible to miss: the giant clam. Its huge, fluted shell frames a soft mantle shimmering with electric blue, green and gold. As the world’s largest living bivalve, Tridacna gigas can reach 1.2 metres, weigh more than 200 kilograms and live for over a century. Across their long lives, these clams record their daily life in their shells, creating an autobiographical shell diary. In our new research, we read one of these shell diaries to reconstruct month-by-month climate conditions at Jiigurru (also known as the Lizard Island Group), in the northern Great Barrier Reef. The shell’s story reveals that, before widespread industrial-era warming, Jiigurru’s summers were cooler than today, while winters were surprisingly similar. How can a shell keep a diary? As a giant clam grows, the cycle of day and night produces microscopic daily lines in its shell, while the changing seasons produce broader annual bands. Like tree rings, these layers turn the shell into a diary. The growth lines provide the dates, just as we date entries in our own diaries. The surrounding seawater writes the content by...

A dolphin who harasses fish until they regurgitate their food – then swoops in to steal it – has astonished University of the Sunshine Coast researchers who have documented this novel feed...

Scientists have been monitoring the reef’s health for the past 40 years.

Marine researchers in Australia’s Great Barrier Reef were astounded when they saw a bottlenose dolphin chasing a bigeye trevally until it vomited, before eating what the fish had just spewed up. "I started screaming." Scientists were filming dolphins in Australia, when this happened Romney Edwards-Francis, a PhD candidate at University of the Sunshine Coast in Queensland, first saw the unusual behaviour while snorkelling on a visit to Lady Elliot Island Eco Resort for the Leaf to Reef Project. Edwards-Francis had heard from master reef guide Pieter Demmers and marine biologist Jacinta Shackleton that a dolphin called Bubbles, who often visits the island, was known for a strange behaviour. “He basically chases this one fish. The fish throws up. He eats the vomit,” explains Shackleton. Whale vs dolphin: what's the difference? “I can’t express to you how rare this behaviour is." 'Tail walking' dolphin filmed in California She’s seen this happen several times. Bubbles even seems proud of his smart hunting strategy. After gobbling down the barf, “he turns his head straight towards me, does this really long click, and it's almost as if he's saying like, ‘Look what I did! I got the food. I'm so smart.’,” she says. Edwards-Francis...