crown of thorns starfish, an introduction
Dr. Kelli Anderson
The crown of thorns starfish (COT) feeds on live coral, and outbreaks have devastated coral reef ecosystems in the Indo-Pacific region. Affected reefs can take decades to recover. But did you know that under some circumstances the COT can benefit reefs?
When COT numbers are balanced, the naturally occurring predator prefers to feed on fast growing coral species. This can actually help slower growing species compete for space, thus encouraging biodiversity. However problems can occur if excess nutrients enter the marine environment, for example after floods, because this indirectly helps COTs to multiply more efficiently and reach plague proportions. Not good news for reefs at all!
When COT numbers are balanced, the naturally occurring predator prefers to feed on fast growing coral species. This can actually help slower growing species compete for space, thus encouraging biodiversity. However problems can occur if excess nutrients enter the marine environment, for example after floods, because this indirectly helps COTs to multiply more efficiently and reach plague proportions. Not good news for reefs at all!
Crown of thorns starfish in Vanuatu
**If you're snorkeling or diving, it might be tempting to collect these guys and help the reef. But please be very careful. Get stuck with those spines and you'll be in a lot of pain!! If you choose to collect them make sure you wear good quality kevlar gloves, or better yet take them with out touching them at all! |
In the beginning, well meaning ocean lovers were collecting COTs, cutting them up then disposing of them in the ocean. Unfortunately the cut-up sections of the animal are able to regenerate and they ended up with even more animals! Another more successful approach to COT control has to been to collect the animals and either bury them on land (as they do in some parts of Vanuatu) or inject them with acid. Researchers from James Cook University recently developed a single injection method that kills the COT within a day. You can check it out here.
A serious problem in the Indo-Pacific
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