Crown of Thorns: Ideas about its eradication?

[Newreeflady]

I am carrying this over from a much less productive forum I guess I am hoping that if we all throw ideas out, and enough people care, a solution will be approached.

So, as I understand it, the verdict currently is that the additional organic components promote planktonic or other sources of food on which the spawn feed and this causes a higher survivability of offspring which in turn breed more of these starfish.

So, do they have any predators? Are there any other factors at play here? Are the adults producing more offspring or living longer due to some change in ocean chemistry? What ideas, other than manual injection of the legs of these creatures by divers, are being explored to reduce the population?

All ideas and posts are good ones. We all need to throw in on this, maybe research will somehow be advanced.

-A

 

[Samala]

Humphead wrasse, Cheilinus undulatus, are predators but are themselves facing habitat loss and over fishing for typically the Japanese and Philippine markets leading to smaller populations of these enormous fish. They are listed as Endangered by the IUCN Red List.

It is very hard to name another fish or invertebrate predator for crown of thorns. Their toxicity really eliminates them from the menu of many creatures.

Fishbase.org entry on the wrasses.

>Sarah

 

[Newreeflady]

Wow, that looks like a neat fish! What a shame I hope that the overfishing will cease, I hope the upcoming conference in Hong Kong is productive in figuring a plan for this species.

Do you think this has had a great effect on the proliferation of the COT?

-A

 

[Samala]

I really dont think the loss of a predator for COT has helped the situation at all. As you've stated the population spike seems to be driven by higher than normal survival rates of their larval stages which eventually become adults that go on to reproduce. It seems to fit that predators arent keeping up with curtailing the reproductive age animals because they are themselves in short supply. I'm not sure what animals consume the larval stages of COT.. that would be interesting to find out.

>Sarah

 

[SerranidTerror]

Yeah unfortunately COT problems were just a blip in my classes in college. I have also not heard of any solutions to this problem. So your posts are going unanswered for a reason. (We can only hope some biologist/ecologist is busy at work somewhere close to an answer.)

I didn't know the Napolean Wrasse ate those COT btw...learn something new every day. Those fish are enormous. I do know there are some areas of the pacific (or so I have been told by some respectable free divers) where the numbers of those fish are still good, thanks in great part to local laws.

 

[Newreeflady]

Definitely, finding out what eats the larvae would be a good call!

I guess, as a chemistry major, I assume there ARE biologists/ecologist on this forum who will either be motivated by the post or maybe have more info than we have.


-A

 

[RGBMatt]

Crown of thorns have been around for hundreds of thousands of years. Why should they be eradicated? Coral damage caused by COT blooms is a natural process, whether we like it or not.

This is yet another example of humans trying to manipulate something we don't fully understand.

 

[mr.wilson]

<a href=showthread.php?s=&postid=6957462#post6957462 target=_blank>Originally posted</a> by RGBMatt
Crown of thorns have been around for hundreds of thousands of years. Why should they be eradicated? Coral damage caused by COT blooms is a natural process, whether we like it or not.

This is yet another example of humans trying to manipulate something we don't fully understand.

I wouldn't have said it that harshly, but I understand your frustration and wholeheartedly agree with your position.

Humans have a duty to tip the scales of nature only to correct damage that we have done. If we cut too many trees down, we must put out some forest fires to balance our impact. On the other hand, we need to respect the natural order and allow some forest fires, as they serve a purpose in the cycle.

Oceans are the same. If nature elects crown of thorn starfish to rule the world, I second the motion.

I'm sure they will crash at some point in time, and we will be printing "save the COT" bumper stickers.

As they say in the commercial "It's not nice to mess with mother nature".

 

[logans_daddy]

as far as i understand the situation the increase in COT populations is a result of "damage" caused by us. if im not mistaken....the prominent theory is that excess algae blooms are substantially increasing the survival rates of COT at the larval stages. where are the excess algae blooms coming from? large amounts of nitrates and phosphates being washed out to the ocean from heavily cultivated farmland. what is the primary cause of this run off? irresponsible foresting and agricultural practices. is the COT dilemna a natural process? absolutely not. RGBmatt and mr. wilson...if you were simply refering to the natural cycles in COT populations to offest the smothering populatoins of staghorn coral.....i would agree with you both 100% but i believe you are both way off mark. to follow your logic mr. wilson, it would seem that nature has elected us to rule the world...so who cares if were depleting the ozone, exhausting our natural resources, and causing irreversible damage to our weather patterns....lets keep on trucking....that sucks! we have an obligation to attempt to restore the nature's balance that we do our best to knock of kilter daily.

 

[Lev F.]

Harlequin Shrimp go after juvenile crown of thorns, but Triton Trumpet Snails are also major predators of the COT. But the Triton Turmpet is also in danger because of the popular use of it's shell in the Curio trade. Sad.

 

[RGBMatt]

<a href=showthread.php?s=&postid=6957813#post6957813 target=_blank>Originally posted</a> by logans_daddy
as far as i understand the situation the increase in COT populations is a result of "damage" caused by us.

Crown of Thorns blooms are believed to have been occurring for thousands of years, as suggested by COT spine accumulations in sediments. It is doubtful that human activity has anything to do with it. The "algal bloom" hypothesis you proposed is pure speculation.

The real issue is that corals today are subjected to a variety of other stresses, and less able to recover from catastrophic events such as starfish predation.

 

[logans_daddy]

your are absolutely correct...blooms have been occurring for thousands of years...however, the part you are leaving out is that the blooms are now overlapping. these overlaps are absolutely a new occurence.

there has been long term studies done on how algae affects these COT blooms and it is FAR from speculation.

i will concede that other problems(i.e., bleaching due to global warming and COT predator depletion) complicates the issue.

shawn:bum:

 

[Newreeflady]

I am sorry to have written "eradication" when what I was meaning was to find out the cause of the large increase that has caused them to be problematic, and try to counter it.

I absolutely believe that nature happens and who are we to stand in the way. But, in this case, it could be that people happened and we have made this a problem, so we should do something about it.

I think it's silly at times the cities who build dams around themselves in hope of holding the tide out (i'm bad with geography, maybe the dutch or someone over there has such a complex town.) Look at what happened in New Orleans. I can see this happening again this year.

But, back to COT, thank you logans_daddy for clearing that up. I didn't mean to sound like someone who likes to go killing species just because they are killing something I love. I just don't want to see the reefs all disappear because we have caused this problem and didn't give it the attention it needed. It sounds like it could be many factors, algae blooms, lack of predators, all possibly influenced by us. What a shame.

-A

 

[auSS/Tin]

There was a special on Discovery recently about the COT problem. The Australlian governement has a vessel on the Great Barrier Reef that has a team of divers that work 24/7 3 dives a day that are tasked with killing COT's as quickly as they can. The chemical that they were using was not disclosed, but they showed the divers inserting a large thick guage needle in the body of the COT and injecting a poison. Whatever the chemical is it must not be too harmful because they just left the bodies behind. Is this the correct thing to do I don't know. I agree that we as humans do try to control to many things that are natural, but we do have a responsibiltiy as stated above to help correct a problem that we might have started. I also agree that the COT blooms have occured before, but evidence indicates that the current blooms are coming at a much faster pace than before. Mother Nature is fickle and we cannot control the direction things will go sometimes.

Bill

 

[SDguy]

<a href=showthread.php?s=&postid=6991882#post6991882 target=_blank>Originally posted</a> by auSS/Tin
There was a special on Discovery recently about the COT problem.
Bill

Actually this thread pretty much reads like a transcript of that show

 

[Aquaman]

save the reefs, shoot the humans!

 

[Newreeflady]

Or, alternatively, "save the reefs, TEACH the humans!"


-A

 

[Aquaman]

Naw, to many humans here anyway! time to thin the herd :eek1:

 

[logans_daddy]

<a href=showthread.php?s=&postid=6991882#post6991882 target=_blank>Originally posted</a> by auSS/Tin
The Australlian governement has a vessel on the Great Barrier Reef that has a team of divers that work 24/7 3 dives a day that are tasked with killing COT's as quickly as they can.
Bill

i recall seeing this special also. I remember shaking my head in a very sad sort of way thinking about the futility of this remedy. if i remember correctly....i think it was said that unless every arm is injected that the COT would be able to recover. what are the chances that these divers...who dive for 8 hour shifts injecting hundreds, if not thousands of COT, get every arm of every COT?

this solution is very typical of the times we live in....why solve the problem when we can simply apply a band-aid and let our children worry about what happens when the adhesive wears out.

 

[Newreeflady]

I agree, this remedy seems close to useless in the long term.

-A