Scientists Use Starfish Pheromones to Save Great Barrier Reef

For 60 years, pizza-sized starfish have been devouring Australia's Great Barrier Reef, and scientists finally have a clever new weapon to fight back.

Crown-of-thorns starfish are natural reef residents, but human activity has turned them into a nightmare. Overfishing their predators and pollution-fueled algae blooms have caused their populations to explode every 15 years since the 1960s, with a fifth outbreak now emerging.

The numbers are staggering. A single female can release 200 million eggs each year, and one adult eats enough coral annually to destroy 110 square feet of reef. When millions of these spiny invaders swarm together, they can reduce a thriving reef to rubble in weeks.

Until now, conservationists have fought these outbreaks by killing starfish one at a time. Divers in Okinawa once removed 1.5 million by hand to save their reef. Scientists later developed methods using vinegar injections and even created an underwater robot assassin called the RangerBot.

But molecular biologist Scott Cummins from Australia's University of the Sunshine Coast saw a better way. After years studying how sea creatures communicate through chemical signals, he discovered that crown-of-thorns starfish release specific peptides to find each other for mating.

His team created synthetic versions of these pheromones, nicknamed "Acanthaster attractins." In laboratory tests, the chemicals worked like a dinner bell, drawing adult starfish straight toward the source. The best part? The pheromones are completely nontoxic.

Why This Inspires

This breakthrough transforms an exhausting battle into smart warfare. Instead of chasing millions of venomous, toxic-slime-releasing starfish across vast reef systems, conservationists can now lure them together and eliminate them efficiently. The approach mirrors nature's own communication systems, turning the starfish's survival instinct against them.

Marine biologist Maria Byrne from the University of Sydney calls the method promising but notes that real reefs are chemically complex environments. Field trials will determine whether the pheromones work as effectively in nature as they do in the lab.

Cummins is optimistic as his team prepares to test the approach on the Great Barrier Reef itself. "Australians have been fighting against [these starfish] for 50 years," he says. After decades of losing ground to these coral-eating invaders, researchers are ready to shift the balance back toward protection and recovery.

The timing couldn't be better, with coral reefs worldwide facing mounting pressures from climate change and human activity. A cost-effective way to control crown-of-thorns outbreaks gives these vital ecosystems a fighting chance at survival.