Effect of Crown of Thorns (COT) Season

[paolov]

'Tis the season for Crown of Thorns in Anilao, batangas Philippines.

What say you on then and their impact on the reef?
Ignore them or do what to them?


paolov

 

[Zippsy]

Apparently, you can not kill them unless you bring them up and bury them or inject them with some lethal concoction. Cutting them up may allow them to multiply faster since they can regererate legs and half bodies can regenerate into two COTs. Both methods of killing them noted above have some significant risks involved so I just usually push them off the reef with a metal pointer and make them start their climb again. I know this only slows them down but....

FYI, just moving them has it's own risks. One dive saw me move a COT with a pointer. He figured that he should help the reef too so he grabbed one with his bare hand to move it. He found out how silly that was very quickly. Ever since then, if I'm in an area with COT, I alwasy make sure to point out to every diver what they are and how dangerous they are.

 

[jplacson]

Paolo... these are very damaging to the reefs...Australia has been trying to control them for quite a while now.

A lot of divers here in the Philippines have been doing 'clean-up' dives for these annoying things. I'm trying to put together a team of my own as well.

Your best bet is to bring a sack, and buy a pair of long tongs... pick them up and sack them... just be careful since their thorns do penetrate the sack as well. Do not poke/stab them, since I heard that they release a mist of eggs in a last ditch effort to propagate their species... so stabbing one will release thousands more in egg form. (or something like that)

I'm thinking of just drying them out in the sun... wait til they die, and turn them into decor or something... maybe tourist souveniers??? HAHAHA

 

[DORSETBOY]

Well intentioned attempts to reduce COT populations by collection / poisoning etc are unfortunatley a waste of time. COT outbreaks will in due course reduce to normal population levels in their own time but the problem is that by this point a hell of a lot of damage will be done.

Will have a look for some of my uni research and see if I can post details on line here.

Current thinking links COT outbreaks on the GBR to runoff of nurtrients along the eastern australian coast, they seem to occur when there has been particularly heavy rainfall for example. Another factor is the reduction in the populations of their predators for example by shellfish collectors.

COT outbreaks may well be quite natural and poss occur without the impact of people, it's likely though that we are making the situation worse.

 

[Zippsy]

I'm thinking of just drying them out in the sun... wait til they die, and turn them into decor or something... maybe tourist souveniers??? HAHAHA

That got me thinking (always a bad sign). Why don't we just get some Chinese doctor to start spreading the rumor that COT pricks are better at keeping you young and virile than sharks' fin soup? Two birds, one stone?

 

[IslandHopper]

Around here, trying to do away with the COT's just gives us something to do while we're diving

 

[bermudaskink]

I went around one little bit of the GBR injecting COT with sulphuric acid while assisting with a programme trying to eradicate them from one dive site.... later after talking to lots of different people including scientists where I was working in Oz, I discovered that there is nothing we can really do about COT just like DORSETBOY says..... most agree now that there are natural outbreaks of these blighters, and that reefs have recovered from outbrakes in the past.

Seems hard to just sit by and watch them eat up so much when the reef gets so much SH** from humans now anyway....

 

[archman]

A more efficient use for those acid-filled syringes would be to spear cyanide fishermen... it'll take THEM longer to recover than Acanthaster, and they're a dangerous exotic to boot!

 

[paolov]

update

http://www.scubaboard.com/showthread.php?p=1076267#post1076267

 

[Hank49]

Seems hard to just sit by and watch them eat up so much when the reef gets so much SH** from humans now anyway....

I agree. But on Boracay in 99 they got so bad that tourists were stepping on them in the shallow beach. So we tried to clean them out. "Tried" is the key word here. Hank