The Attack Of The Killer Starfish

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The decline in coral reefs has been attributed to a number of different causes including over fishing, pollution, typhoons and global warming.

A factor, especially serious for coral reefs near Japan, has been a large increase in the number of a thirteen armed starfish called "The Crown-of-Thorns," which feasts on coral reefs.

As is usual in these complex multiple cause problems the contribution of each individual factor is difficult to quantify.  An increase in the number of typhoons has not only increased the physical damage but has stirred up more sediment, increasing the amount of plankton on which the young starfish feed.  Current methods of dealing with the starfish have not proved effective.  Poisoning them harms other valuable creatures, while physically cutting them up is compromised by the starfish's ability to grow whole creatures from the severed parts.

Recently researchers in Japan have discovered that sea urchins contain a chemical compound that attracts the starfish by acting as a feeding stimulant.  Chemists have now extracted and identified two active chemicals from sea urchins, and used them successfully to lure the notorious coral eating starfish away from coral reefs.

So next time you snorkel near a coral reef, be thankful that new research is able to save at least some of them.