Destructive starfish is delicious to some

  Last updated May 21, 2020 at 4:13 pm

Topics:  

Fish might be our best weapon for controlling Crown-of-Thorns starfish on the Great Barrier Reef.


starfish_crown of thornes_coral reef

Crown-of-thorns starfish moving on a coral outcrop on the Great Barrier Reef. Credit: Kroon/AIMS




Why This Matters: Crown-of-Thorns are devastating the Reef.




Crown-of-thorns starfish, the scourge of Australia’s Great Barrier Reef, may have more natural predators than we thought.


A novel study of fish faeces and gut contents suggests a number of fish are interested in Acanthaster solaris, including popular eating and aquarium species.


The native starfish has surged to plague proportions three times since 1962, with a fourth under way. Each time it has caused a significant loss of large amounts of hard coral.


Increasing the amount of predation has long been touted as a potential solution to preventing outbreaks but, aside from a mollusc called the Giant Triton (Charonia tritonis), identifying what eats it has proved challenging.


Fish feast on spiny starfish


Now a team of scientists led by Frederieke Kroon from the Australian Institute of Marine Science has applied a genetic marker unique for crown-of-thorns, developed at AIMS, to detect the presence of starfish DNA in fish faeces and gut contents.


Over three years, they used it on samples taken from 678 fish from 101 species, comprising 21 families, gathered from reefs experiencing varying levels of starfish outbreak.


The results, published in the journal Scientific Reports, confirm that at least 18 coral reef fish species – including Spangled Emperor (Lethrinus nebulosus), Redthroat Emperor (Lethrinus miniatus) and Blackspotted Puffer (Arothron nigropunctatus) – eat young or adult starfish.




Also: Researchers find weakness in deadly Crown of Thorns




Significantly, nine had not been previously been reported as doing so, including the Neon Damsel (Pomacentrus coelistis), Redspot Emperor (Lethrinus lentjan), and Blackspot Snapper (Lutjanus fulviflama).


“Our findings might also solve a mystery – why reef areas that are closed to commercial and recreational fishing tend to have fewer starfish than areas where fishing is allowed,” says Kroon, who worked with colleagues from AIMS, the CSIRO and the Great Barrier Reef Marine Park Authority.


New management approaches to mitigate crown-of-thorns outbreaks by enhancing coral reef fish predation should be seriously considered, the researchers write, “both on the GBR and on Indo-Pacific reefs more broadly”.


More Like This


If we can put a man on the Moon, we can save the Great Barrier Reef


The Great Barrier Reef bleached for the third time in five years, and its more widespread than before




About the Author

Nick Carne
Nick Carne is the Editorial Manager for the Royal Institution of Australia.

Published By

Cosmos is a quarterly science magazine. We aim to inspire curiosity in ‘The Science of Everything’ and make the world of science accessible to everyone.


At Cosmos, we deliver the latest in science with beautiful pictures, clear explanations of the latest discoveries and breakthroughs and great writing.


Winner of 47 awards for high-quality journalism and design, Cosmos is a print magazine, online digital edition updated daily, a daily and weekly e-Newsletter and educational resource with custom, curriculum-mapped lessons for years 7 to 10.


Featured Videos

Placeholder
Fitting natural water treatment processes back into the landscape
Placeholder
Protecting the Great Barrier Reef at the National Sea Simulator