The crown-of-thorns starfish, which has the scientific name (Acanthaster planci), is a beautiful creature with a massive appetite for coral. It is a native of many coral reefs around the world including the Great Barrier Reef.

Facts About Crown-of-Thorns Starfish Outbreaks

The population of the crown-of-thorns starfish undergoes cyclic outbreaks roughly every 17 years. Since the 1960s, the Great Barrier Reef has had four recorded outbreaks. The most recent began in 2010 and is still going on.

The crown-of-thorns starfish has a voracious appetite; it takes only 12 starfish to devour a reef with the area of a football field. It has digestive enzymes in its stomach that enable it to absorb nutrients from the coral, leaving only a white scar of a coral skeleton.

While the earlier outbreaks soon naturally receded, the later ones have been lasting longer and becoming more frequent. As a result, the coral has not had sufficient time to recover, and it has been in a steady decline. The Great Barrier Reef now covers half the area that it did in 1985, and that coverage could halve again in 2022 – six years from now!

The decline of the Great Barrier Reef has been attributed to three major causes: coral bleaching (10%), crown-of-thorns starfish (42%), and storm damage (48%). While there is some debate over the causes of the current, ongoing starfish outbreak, it is believed to be caused by nutrient runoffs, overfishing and/or climate change.


What’s Being Done About It?

The Association of Marine Park Tourism Operators (AMPTO) is running a human dive team culling effort. The organization dispatches 12 divers to manually inject starfish. While the divers have been able to save from critically threatened reefs, the Great Barrier Reef is simply too large for AMPTO’s teams to handle.

The Queensland University of Technology (QUT) is developing a robot that can autonomously identify and inject starfish.

The Australian Institute of Marine Science (AIMS) has been researching the Giant Triton Snail (Charonia tritonis), which is one of the few predators of the crown-of-thorns starfish. The scientists want to learn about the possibilities of using the snails to control the starfish populations.

How can you help?

Become a citizen scientist. You can take pictures of the starfish to help refine the robot’s detection system. Visit the QUT website to learn how to report on the starfish’ s location, plus depth and light conditions. You can also download the Eye on the Reef app to report your findings. You can get the App from Google Play or Apple’s App Store. 

Source of the infographic: Reef Free