Between 1947 and 1960, about 10,000 giant tritons were removed each year from the Great Barrier Reef, according to a scientific review published in 2017 in the journal Diversity. Their shells sold well. Sixty years later, this same sea snail is being asked to save the reef.
The idea can be summed up in one sentence. The giant triton (Charonia tritonis) eats crown-of-thorns starfish, those spiny sea stars that devour coral, so it would be enough to raise and release thousands of them.
On paper, it’s appealing. But where does research really stand in 2026, and what is Australia doing meanwhile in the face of crown-of-thorns outbreaks? We cross-checked publications from AIMS, the marine park authority, and dated press reports.
Why is the crown-of-thorns devastating the Great Barrier Reef?
The crown-of-thorns feeds almost exclusively on coral, and its populations explode in waves. The Great Barrier Reef Marine Park Authority (GBRMPA) records four major outbreaks since the 1960s, the latest starting around 2010. According to monitoring data from AIMS cited by ABC News in January 2026, the starfish accounts for up to 40% of coral lost over four decades.
The mechanism is simple. The starfish turns its stomach over a colony and digests the living tissue, leaving only a white skeleton that algae then cover. ABC News compares its daily ration to a plate of coral. A single female can lay hundreds of millions of eggs. When density exceeds a certain threshold on a reef, coral loss outpaces regrowth. Bleaching linked to heat waves adds to this pressure, and the two phenomena accumulate on the same reefs (we detail these threats to corals in another article).
Yet the fifth wave seems already here.
In January 2026, ABC News reported an accumulation of adults over about 240 kilometers between Cairns and Lizard Island, ahead of the cycle observed so far. Roger Beeden, chief scientist at GBRMPA, wants to act quickly. Outbreaks usually start in this northern area, then move south over about ten years, according to GBRMPA. This timeline makes early detection decisive.
A vocabulary clarification is necessary. The crown-of-thorns is a native species of the reef, not an invasive species, even though some press headlines have presented it as such. On the Great Barrier Reef, researchers now often refer to it as Acanthaster cf. solaris, the Pacific form, rather than A. planci. To place the animal in its family, our fact sheet on the sea star covers the basics.
Does the giant triton really eat crown-of-thorns?
Yes, the giant triton preys on the crown-of-thorns, but field data on its attack frequency remain sparse. The review by Cowan and colleagues (2017) notes that it prefers other sea stars when given a choice and that its attacks are not always lethal. No one has yet shown that it could, alone, stop an outbreak.
What is solid is the starfish’s reaction, which flees as soon as it senses the triton’s scent. AIMS announced this as early as September 2017, describing a constant alarm reaction to the snail’s secretions, and the review published in 2022 by Cherie Motti, Scott Cummins, and Michael Hall confirms this short-distance deterrent effect. This chemical trail interests both researchers and the snail itself, because an olfactory lure placed on a reef would probably cost less than breeding in tanks. It remains at the research stage.
Yet the triton is only one predator among others.
The 2017 review lists about 80 reef species that consume the crown-of-thorns at some stage of its life, from fish to invertebrates. A starry pufferfish ate a 20 cm adult in less than ten minutes. The Napoleon wrasse is also among the cited predators. The authors estimate that the disappearance of predators alone does not explain the outbreak triggers. The triton is simply the most media-friendly.
| Reference | Giant Triton | Crown-of-thorns |
|---|---|---|
| Scientific name | Charonia tritonis | Acanthaster cf. solaris (often called A. planci) |
| Size | Shell up to 50 cm (Motti et al., 2022) | Up to nearly one meter in diameter (GBRMPA, 2026) |
| Diet | Sea stars, including crown-of-thorns | Almost exclusively living coral |
| Larval phase | Very long, possibly several years | A few weeks in plankton (order of magnitude) |
| Status | Rare, protected in Queensland waters | Native species, controlled by targeted culling |
Where does giant triton breeding stand in 2026?
No one has yet succeeded in raising a giant triton larva to the stage of a snail fixed on the substrate. AIMS obtained more than 100,000 larvae in 2017, and the 2022 review reports up to 1.47 million larvae per spawning season from breeders kept in captivity. None reached metamorphosis. A genomic study published in July 2026 in DNA Research reached the same conclusion.
Let’s revisit the 2017 announcement. The Australian government funded a trial of 568,000 Australian dollars, planned from mid-2017 to June 2019, as part of a 27.4 million plan dedicated to crown-of-thorns. The stated goal was to understand the signals triggering metamorphosis. Yet some of the press summarized the matter as “baby tritons” ready to be released, which primary sources never said.
The bottleneck comes from biology.
Triton larvae are said to be teleplanic, capable of drifting across an ocean, and this phase could last years, according to Motti and colleagues. A related species reaches 4.5 years. Keeping a larva alive that long in tanks, with the right food and chemical signals at the moment of settlement, remains out of reach. And the species has separate sexes, complicating reproduction when adults are rare. In short, breeding giant tritons released by the thousands on the reef is still hypothetical.
What research has produced is less spectacular but useful. We now have a published genome, data on the snail’s salivary glands and venom, and a better idea of the molecules that repel crown-of-thorns. Should this be seen as a dead end? Impossible to decide for now.
What is Australia doing against the current wave of crown-of-thorns?
The operational response relies on divers. Since 2012, the GBRMPA control program sends teams who inject a single dose of household vinegar or ox bile into each starfish. For the 2025-2026 season, GBRMPA reports 64,879 crown-of-thorns culled on 220 reefs, covering 13,210 hectares.
Thus, culling remains targeted. GBRMPA has identified 500 priority reefs and treats 200 to 250 per year, with six boats. Teams spent 17,528 hours underwater in the last season. The switch to single injection in 2014 changed everything since previously between 10 and 25 injections per starfish were needed. The story of this method is told in our article on vinegar against crown-of-thorns.
The result is measured reef by reef.
On John Brewer Reef, GBRMPA indicates that culling reduced the average from 3.5 to 0.35 starfish per survey, with hard coral cover maintained between 31 and 42%. According to ABC News, the program costs about 25 million Australian dollars per year. Officials cited estimate capacity would need to double to keep up with the new wave.
Can you encounter a giant triton while diving on the Great Barrier Reef?
It’s possible, never guaranteed. The species has become rare over much of its range after decades of collection for its shell, and it remains protected in Queensland waters. No operator can honestly promise to see one. If you spot one, watch without touching or moving the animal or its shell, because a living triton counts more for the reef than any photo.
However, the most useful question for you concerns the crown-of-thorns.
Its spines cause painful stings. If your dive crosses a reef currently undergoing culling, the club’s briefing remains the only reference on zones to avoid. The site visited, the season, and coral condition vary from reef to reef, and the Great Barrier Reef stretches about 2,300 kilometers. A turquoise photo on an operator’s page tells you nothing about the reef’s condition this month. Ask the club which reefs it frequents currently.
Reporting a crown-of-thorns takes a few minutes after diving. The free Eye on the Reef app from GBRMPA accepts geolocated observations of crown-of-thorns, as well as rare animals. To see how these stars and their neighbors protect themselves, our marine animal defense mechanisms provide other examples. These minutes of data entry serve the reef more than the hope of spotting a triton.
FAQ
Can the giant triton save the Great Barrier Reef?
Not by itself, given current knowledge. AIMS researchers wrote in 2022 that its ability to control an outbreak remains to be established. It preys on crown-of-thorns, but breeding has never produced juveniles.
Have giant tritons been successfully bred in captivity?
Adults spawn in tanks and produce hundreds of thousands of larvae. No larva has yet reached metamorphosis, according to a 2022 review and a genomic study from July 2026.
How many crown-of-thorns outbreaks has the Great Barrier Reef experienced?
GBRMPA counts four since the 1960s, the most recent starting around 2010. In January 2026, ABC News reported the emergence of a fifth wave between Cairns and Lizard Island.
How are crown-of-thorns killed on the Great Barrier Reef?
Divers from the control program inject a single dose of household vinegar or ox bile into each starfish. For 2025-2026, GBRMPA reports 64,879 starfish culled on 220 reefs.
Sources
- Crown-of-thorns starfish control program (Great Barrier Reef Marine Park Authority, 2026)
- A Review of the Giant Triton (Charonia tritonis), from Exploitation to Coral Reef Protector? (Motti, Cummins et Hall, Diversity, 2022)
Photo: David Burdick, NOAA, Wikimedia Commons, public domain
{“@context”:”https://schema.org”,”@type”:”FAQPage”,”mainEntity”:[{“@type”:”Question”,”name”:”Le triton géant peut-il sauver la Grande Barrière de corail ?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”Pas à lui seul, en l’état des connaissances. Les chercheurs de l’AIMS écrivent en 2022 que sa capacité à contrôler une épidémie reste à établir. Il chasse l’acanthaster, mais l’élevage n’a jamais produit de juvéniles.”}},{“@type”:”Question”,”name”:”A-t-on réussi à élever des tritons géants en captivité ?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”Les adultes pondent en bassin et produisent des centaines de milliers de larves. Aucune larve n’a encore atteint la métamorphose, d’après une revue de 2022 et une étude génomique de juillet 2026.”}},{“@type”:”Question”,”name”:”Combien d’épidémies d’acanthasters la Grande Barrière a-t-elle connues ?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”La GBRMPA en compte quatre depuis les années 1960, la plus récente ayant démarré vers 2010. En janvier 2026, ABC News signalait l’émergence d’une cinquième vague entre Cairns et Lizard Island.”}},{“@type”:”Question”,”name”:”Comment tue-t-on les acanthasters sur la Grande Barrière ?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”Des plongeurs du programme de contrôle injectent une dose unique de vinaigre ménager ou de bile de bœuf à chaque étoile. Sur 2025-2026, la GBRMPA annonce 64 879 étoiles abattues sur 220 récifs.”}}]}
