Crown of Thorns Sea Star!

[Hank49]

This may sound crazy...but maybe in the long run the COTs are good...and a natural part of the healing process of a weakened, damaged reef.

 

[World Wide Diver]

I don't know too much about cot physiology, but they do seem to be made up of a high % water - a bit like a 'cushion'. When removed from water, they quickly lose their water content and 'flatten' out.

I do think injection and removal would better - especially when you have piles of them on table corals.

 

[World Wide Diver]

To add; COTS are more active in the dark than the daytime. In the daytime they rest under table corals and in crevices. The COT gun developed has a long needle to inject COTS that hide in crevices and under coral - without damaging coral.

Please can people who have use these guns comment on this.

WWD

 

[Gen San Chris]

Me and John went across the bay to the Glan area yesterday and got 318 Crown of Thorns! We were very happy at the front of the Hotel that a Dutch Guy is hoping to open one day as we only got about 20 there while just a while ago with Jane and Andrew (WWD) we got around 400! I think that this shows that if you whack them good then the corals get a bit of a breathing space which allows them to recover a bit!
We Will keep on getting them until they are in easily controlable numbers!

 

[drgreenthumb]

Hello Gen San Chris,
Im a newbie to this site and find your report interesting. Im from Negros Occ and have seen this problem excalating into huge proportions. For ex., When I first went to the coastal town of Sipalay 15 yrs ago (when it was not on the guidebooks or even rooms were available to tourists, I do NOT recall seeing COT there but during the last 5 yrs had really "blossomed"! The coastal coral formation that I had remembered when I was younger as well as the marine life is now completely decimated! The eastern part of Negros (oriental part-cebuano speaking) has increased as well and it present on the coasts of Dumaguete, Bais, and Hinobaan. Everything near the Sipalay coast is DEAD while the area is increasing in tourists but divers dont usually see this issue because the sites are further from the coast. These areas eversince werent prone to overfishing as compared to Dumaguete, Bacolod or Iloilo.

Im on the band wagon collaborating with post grads at Siliman University that climate change has favored them to multiply much faster along with the deterioration and stress of corals together with overharvesting of tritons from many decades.

Its really a catch 22 that tritons can keep the COT in check but at the same time needs a healthy ecosystem around them.

Maybe an alternative is to catch and preserve COT and promote them as souvenirs while breeding tritons and re-introducing back to have a balanced ecosystem?

 

[Gen San Chris]

The preserving of C of T's is an interisting idea but seeing as they are mostly water it would be difficult and the poisen in the spines might not be good for kids to play with!
We ahve now the Camanga Marine Reserve and have noticed that Triton shells are around again but we would like to try a breeding programme if we could find some seeds and get a local Marine Bio interested! Unfortunatly the MSU who teach Marine Bio's are only interested in sea grass and are pretty worthless!
We will keep on removing them until they all go away!

 

[Chuck SS]

Glad to see a spirted discussion still going on. Some thoughts: Take them out of the water and you remove nutrients from the ecosystem. Needle and inject them and you may leave something amiss also. Do nothing and watch your reefs get decimated. It's a tough call but nature needs a helping hand at times and yes Virgina, mankind is a major part of nature. I favor removing them as it's very specific and can be quantified and tailored to the individual reef or reef area. I recognize that manpower and disposal are the problems here. In some decimated areas perhaps the needle guns are the way to go. Above all assist with research and figuring out the problems when and where you can. So far my bet is that contributing factors include some out of balance contributors such as Triton gathering but I feel that this is a smaller problem. One of the major problems seems to be erosion and runoff control. Another very likely major contributor is shifting currents carring their spawn to new reef areas. All in all, for the good, I feel that they often eat themselves out of house and home, die off and then the reef returns although this may take years. Again great discussion!!!

 

[kevinl4270]

Does anyone know of any active removal projects in the Philippines? Or any other similar projects? I will be in Cebu the last two weeks of April.
I am interested in eventually working on reef restoration projects once I retire. 5+ years from now.I am really interested in a thing called BioRock and Reef Balls. Google them. Anyone ever worked on similar projects. Thanks.

 

[grandizer52]

Hawaii, has a huge prob with them too, try to off as many as possible. in the early 80's there was a C/T prob in guam, the military along with a commercial fir did a good cleany cleany

 

[Hank49]

To add; COTS are more active in the dark than the daytime. In the daytime they rest under table corals and in crevices. The COT gun developed has a long needle to inject COTS that hide in crevices and under coral - without damaging coral.

Please can people who have use these guns comment on this.

WWD

I haven't used a specific COT gun but we DID inject them with copper and chlorine back in 99 on Boracay. We did controlled tests where we injected, then trapped them using pots and cages to see what happened over the next few days. We found that you need to use multiple injections, or one in the base of each appendage, to get a kill. They have a reproductive organ in each appendage.
We injected others in only a few appendages and those appendages died. But the remaining ones stayed intact. It reminded me of the movie Terminator, when the hand kept crawling at the end after he was blown up.
We determined that gathering was more efficient, although it appeared to have no real affect after a few months. The COTs just ran their course on the stressed reef.