COTS clean up February 2017

crown of thorns starfish malapascua philippines


crown of thorns starfish malapascua philippines

COTs is what we call Crown of Thorns starfish living in the ocean. These creatures belong in the family of sea stars and are really bad for the reef. They actually eat corals and as you can imagine this is bad for the reef, and all it’s inhabitants.

The COTs eat mainly hard corals and polyps on the reef. They do this by inverting their stomach inside out so that the acid from the stomach is straight on the corals and that dissolves the polyps and leaves their “track” of white dead corals behind them which is easily visible to divers. They can eat up to six square meters of coral per year!

crown of thorns starfish philippines

COTs have natural predators such as Titan trigger fish, Triton Shells and Puffer fishes. But sometimes they cant keep the population of the starfish under control, especially if their numbers have been reduced due to fishing, or collection for souvenirs in the case of the Triton shells.

So a few weeks ago when we discovered a cluster of COTs out at Monad shoal and we knew we should do something about it. When we had some staff available we decided to go hunting, we picked them up with bamboo sticks and then put them in big net bags underwater. We are then able to remove them from the water and make compost. Hopefully this will help to keep the population under control and avoid the reef becoming damaged.

The team that went included Seb, Alex, Joshua and Dannie and between them they were able to collect almost 100 COTs

malapascua crown of thorns starfish


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