Dr Scott Ling with a crown of thorns starfish
Original Published Date: 
Friday, November 6, 2020

Full article issued by The ARC Centre of Excellence for Coral Reef Studies.

A world-first study by scientists at the ARC Centre of Excellence for Coral Reef Studies on the Great Barrier Reef shows crown-of-thorns starfish have the ability to find their own way home – a behaviour previously undocumented – but only if their neighbourhood is stocked with their favourite food: corals.

The researchers observed the starfish emerging from their shelters in the afternoons so they could feed on coral during the night before returning home at dawn.

“The crown-of-thorns starfish often partied all night, slept-in and only those with a well-stocked larder found their way home – so it’s very much a teenager model of behaviour,” said lead author and ARC Future Fellow, Dr Scott Ling, from the Institute for Marine and Antarctic Studies at the University of Tasmania.

The researchers used in-situ time-lapse photography to track the movements of 58 starfish in the northern and southern Great Barrier Reef during an outbreak in 2015. In the absence of their preferred Acropora coral prey, starfish were typically homeless and instead roamed up to 20 metres per day.

“Unlike sea urchins that can switch diet once they overgraze kelp forests, results of the time-lapse monitoring indicate that the starfish will consume available Acropora and ultimately eat themselves out of house and home before dispersing in search of new feeding grounds,” Dr Ling said.

Previous outbreaks on the Great Barrier Reef were recorded in 1962, 1979, 1993 and 2009. Though mass-coral bleaching due to global warming is now the greatest threat to coral reefs worldwide, the combined impact of mass-bleaching and crown-of-thorns outbreaks is potentially catastrophic for coral reefs.

Photo credit: 

Dr Scott Ling with a crown of thorns starfish. Credit: Dr Scott Ling.