Friday, May 16, 2008

Crown-of-thorns starfish threaten coral reefs

Crown-of-thorns starfish threaten coral reefs

This surprising header, to me, was found in today's issue of the The Nation, a Thai nation wide English language paper made in Bangkok.

As a long term diver in the Gulf of Thailand, since 9 years and various other parts of Thailand, but mostly in the Gulf, I've seen plenty of Crown of Thorns and they're mean guys.



Here's a not so great picture that I made not too long ago at White Rock near Koh Tao. They demolish coral reefs and are very difficult to destroy, if you cut of a piece of them, they basically live on now as two new crowns of thorns. The only way I know to destroy them is to take them out of the water, which is a completely different story, since their stingers hurt tremendously and give you long lasting scars on top of that.
The article in the Nation mentions injections, which is interesting.
Anyway, without further ado, here's the full length article;
Crown-of-thorns starfish are threatening coral reefs in at least three locations, including a popular destination off Phuket. "These starfish destroy natural reefs," says Niphon Pongsuwan of the Phuket Marine Biological Centre.

Damage to the reefs is evident at Aew island off Phuket, the fifth in the Similan chain and another island off Krabi. In an ecologically sound environment there should be just one crown of thorns starfish for every 100 square metres.

"But in these three locations there are more than 30 per square metre," Niphon says.

In a bid to reduce their damage, centre divers are collecting the starfish from Aew and then destroying them using chemical injections.

Niphon is asking recreational divers to alert national park officials if they encounter the starfish.

"Don't destroy the crown of thorns starfish before you notify officials or else you may face legal action," Niphon says.

4 comments:

soldave said...

They can be a nuisance, and are here around the islands in Okinawa. A couple of dive companies on the outer islands do special weekends where divers go in and remove them from the reefs.

You are correct that if you cut them in half or something they will grow back (like earthworms), but I believe if you cut out their entire centre disc it will kill them.

I read a good article in Dive Training magazine about them a few months ago

Bill said...

If you brought the Crown-of-thorns to the surface, will they die? I'm just curious because there are a few places here in the Philippines right now that have problems with them. Before in Boracay they had a problem and they did use some form of injection.

Camille Lemmens said...

Hi Bill,

Yes, brining them to the surface they will die, however, it ain't easy to do.

An injection sounds like a lot easier to me!

Anonymous said...

From what i understand, you should not cut it completely (since it will grow as 2). Just cut the external skin to expose its soft internals. In that case, fishes and other marine creatures can feed on it and it will die eventually

can anyone confirm on this ?