Crown of Thorns - COT

Crown of Thorns

By most people’s standards, the Crown Of Thorns starfish (Acanthaster Planci) is a beautiful creature. They can have up to 18 arms, can grow almost half a meter in diameter and come in a range of stunning colour varieties.

It’s only when you start to learn a little more about their physiology and life cycle do you realise that they’re actually covered with long, venomous spines and their main purpose in life is to munch on coral!

Coral reefs can get cancer too!

Crown of Thorns (COT) starfish are found on coral reefs in the tropics ranging from the Red Sea, throughout the Indian and Pacific Oceans. It is a coral eating starfish which can destroy vast areas of hard coral reefs within just a couple of month.

Worldwide, coral reefs are facing the danger of COT outbreaks. Popular dive spots such as the Great Barrier Reef of Australia and the coastline of Sharm-el-Sheikh in the Red Sea have not yet recovered from catastrophic outbreaks in the late 1990s. It is believed that the main reasons for the regular explosions in population is the nutrition rich water due to pollution and also the collection of their main predators, the Triton snail (Charonia tritonis) with its beautiful shell, which you find nowadays almost only in souvenir shops.

The authorities of Egypt, Australia and other nations have tried literally everything to get rid of the COT, but the only methods that work are either to inject them with a poison or to collect them and bury them on land.

All reefs in Malaysia are under threat and the reefs on our dive sites are unfortunately no exception. B&J organises monthly events to control the COT. The local Marine Park of Tioman Island also organise a yearly collection where most dive centre on the island participate.

We are always looking for volunteers. Check out our upcoming event calendar. If none of these days match your plans, then still get in touch – we can organise a bespoke event just for you!

If you like to know more about COT and how to conduct COT injections, read the interesting COT Best Practice for Clean ups guide.

Join our next COT event and learn more about the methods to inject this coral eating starfish.