Controlling Crown-of-Thorns Starfish Outbreaks with One Simple Ingredient

Written by on October 9, 2015 in Coral Reefs, Other Marine Life

By now, you’ve probably all heard about the Crown of Thorns Starfish (CoTS) and how they’ve been devastating the Great Barrier Reef (GBR) for years.

Crown of Thorns Starfish. Photo credit: JCU.

Crown of Thorns Starfish. Photo credit: JCU.

A 2012 study found that a CoTS outbreak can destroy 40 to 90 percent of corals on a reef. In the last 50 years, it’s done more damage to reefs than bleaching. A separate study found that coral cover in the GBR declined by more than half in less than three decades. About 42% of that decline can be attributed to CoTS outbreaks.

Scientists have put lots of time and effort into finding ways to control CoTS outbreaks, and in 2012 they were successful on an individual level. They created a protein mixture that was capable of destroying CoTS in only 24 hours. The problem is that it’s expensive and difficult to source.

Now, James Cook University scientists have found a cheaper, simpler solution: vinegar. Regular household vinegar kills the starfish just as effectively as the current drug, ox-bile.

“Currently divers use 10 or 12 ml of ox-bile to kill each CoTS. It’s expensive, requires permits and has to be mixed to the right concentration,” lead author Lisa Boström-Einarsson explained in a news release. “We used 20 ml of vinegar, which is half the price and can be bought off the shelf at any local supermarket.”

In lab tests, the CoTS were all dead within 24 hours. They were also consumed by fish, which experienced no ill-effects.

“There’s no reason to think it won’t work or it’ll be dangerous, but we have to be sure,” Ms Boström-Einarsson said.

Crown of thorns starfish. Photo credit: NOAA.

Crown of thorns starfish. Photo credit: NOAA.

The scientists also recognize that killing the starfish individually isn’t an ideal situation. It requires a lot of manpower and it’s incredibly difficult to keep up with the rapid rate at which CoTS breed, but it’s certainly better than nothing. Several groups are working on population-level controls, but for now this is all we have.

“While it would take an insane effort to cull them all that way, we know that sustained efforts can save individual reefs,” Ms Boström-Einarsson concluded.

To learn more:

Copyright © 2015 by Marine Science Today, a publication of Marine Science Today LLC.

About the Author

About the Author: Emily Tripp is the Publisher and Editor of She holds marine science and biology degrees from the University of Miami's Rosenstiel School of Marine and Atmospheric Science and a Master of Advanced Studies degree in Marine Biodiversity and Conservation from Scripps Institution of Oceanography. When she's not writing about marine science, she's probably running around outside or playing with her dog. .


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