Kill to Save the Reef?

[IceIce]

Sorry if it's been discussed before.
I ran the search engine and couldn't find much.

Inspired by other thread about killing sea urchin, I've had this curiosity for quite sometime and probably some can enlighten me.

I've seen DM kill Crown of Thorns, either by shredding them apart or turn them upside down and put rocks on them.
The DMs then told us that they have to be destroyed whenever we see them during diving as it can help saving the reef.
There are even some activity that invite divers to do 'cleaning', sometimes it's garbage in the ocean and many times it COT killing.
I've seen mass killing by picking them from the ocean and soak them in soap water or put them in the sun to dry.

All the while I live with the answer that everyone gave me, they destroy corals, they over populate, we have to destroy them, to save the reef.

I have ideas in mind that perhaps it's not that wise that we interfere that much.
I suppose everything is there for the reason and for this case, COT over populate maybe because their natural predators are missing and that should be the thing we address to instead of covering mistakes with mistakes.
Shall we execute the COT starfish for doing what they do? Living?

I read not long ago, somewhere in OZ, they kill feral cats to protect some bird, but it ends up as a backfire, overpopulation of rabbits (prey of the feral cats) that destroy the vegetation needed by the birds, in short summary, it creates environmental devastation instead of the original purpose of saving it.
(Removing cats to protect birds backfires on island)

So, it sounds similar to me.
It seems to be norm practice so I kind of think that I probably wrong?
(Although I strongly don't think so since I never buy the explanation of killing after so many years of being told so..), I always feel uneasy about this.

Opinions? Or have you done the reef saving yourself?

Thanks in advance.

 

[Dtaine]

When I'm not in Miami, I'm usually in North-eastern PA; up there we hunt deer not only just for fun, but also because they do overpopulate.

When we remove natural predators sometimes we do have to take their place.

 

[don Francisco]

I can't speak for all situations, but sometimes interfering makes sense.

There might be some sentiment for following a non-inteference policy, since the reefs have been there for thousands of years and done fine without us, but the flip side is that we're already affecting the reefs, so efforts to undo mans effects are jusified.

Certainly, there's no reason not to pick up manmade trash from the bottom. Polution runoff has also favored algae at the expense of coral, fishing has altered the balance of predation, and the accidental introduction of non-native species such as Pacific lionfish to the Caribbean is certainly an un-natural phenomenon that justifies human intervention.

Overall, well considered, focused intervention probably makes sense if done properly. You might adopt the attitude that nature adjusts to changes and would find new equilibrium eventually, but the reef time scale is very long, and we might not want to wait that long.

So far the only intervention I've done, was in Cozumel after Hurricane Wilma. I blew some sand off sponges, re "planted" soft corals and sea fans blown over by the surge, and picked up lots of trash washed onto the reef by the storm. Now that Lionfish have arrived, I'll help in efforts to eradicate them.

I also have a policy of picking up new trash and removing fishing line wherever and wherever I see it while diving.

 

[jswantek]

When I'm not in Miami, I'm usually in North-eastern PA; up there we hunt deer not only just for fun, but also because they do overpopulate.

When we remove natural predators sometimes we do have to take their place.

Dude, I'm in NEPA too...!

This post as me thinking, is it possible to repopulate the natural predators of the crown of thorns, or is there a way of relocating them? Also, what is the root cause of the overpopulation? Perhaps just trying to kill them off is just playing catch-up and not likely to work...

This does seem to be something that's common with aquatic life, similar to the zebra mussels and the snakefish and such...and while it's easy to blame human intervention in hindsight, not all outcomes can be predicted...

 

[Sas]

I have ideas in mind that perhaps it's not that wise that we interfere that much.
I suppose everything is there for the reason and for this case, COT over populate maybe because their natural predators are missing and that should be the thing we address to instead of covering mistakes with mistakes.
Shall we execute the COT starfish for doing what they do? Living?

Sure execute away. If an animal is introduced into an area and is affecting the resident life in a negative way it should be exterminated. The introduction of the species in the first place is interfering so I see it as a problem that needs to be resolved.

For example, if I see any Northern Pacific seastars I collect them all and chuck then in a rubbish bin after a dive. They were most likely introduced by ballast water and are serious pests to the bay I dive in. Northern Pacific Seastar

 

[IceIce]

Appreciate the opinions guys.

This post as me thinking, is it possible to repopulate the natural predators of the crown of thorns, or is there a way of relocating them? Also, what is the root cause of the overpopulation? Perhaps just trying to kill them off is just playing catch-up and not likely to work...

This is the kind of intervention that I thought will have better result. It sounds ideal, if we are doing the effort to find out what is the cause of the unbalance in wildlife then address to it instead of killing, because in long run, the extermination of one species can result in another chain reaction which probably cause more damages in the future.

I agree though that sometime desperate situation needs desperate and fast actions.., and this killing of COT might be one of it. It could be done better maybe, with systhematic method instead of just 'when you see it, kill it' kind of messenge? We might not know when is the limit, we could have not enough supply of COT one day.

In some healtier dive sites, crown of thorn actually grown in reasonable amount, therefore they also playing fair part in keeping the balance of the environment.

 

[Dtaine]

Appreciate the opinions guys.



This is the kind of intervention that I thought will have better result. It sounds ideal, if we are doing the effort to find out what is the cause of the unbalance in wildlife then address to it instead of killing, because in long run, the extermination of one species can result in another chain reaction which probably cause more damages in the future.

I agree though that sometime desperate situation needs desperate and fast actions.., and this killing of COT might be one of it. It could be done better maybe, with systhematic method instead of just 'when you see it, kill it' kind of messenge? We might not know when is the limit, we could have not enough supply of COT one day.

In some healtier dive sites, crown of thorn actually grown in reasonable amount, therefore they also playing fair part in keeping the balance of the environment.

Everyone also needs to keep in mind unintended consequences - if you try to eliminate COT by introducing another predator you might just have two problems instead of one. Also, "synthetic" methods, by which I think you mean using chemicals or instituting some disease or virus into the conversation (if you mean something else please clarify) could have very far reaching affects on other organisms within the ecosystem. Truthfully, simply taking them out one by one might not be efficient, but it certainly doesn't have many unintended consequences.

 

[seaducer]

It is appropriate to kill COT since there is more than likely man-made reasons that the natural checks and balances that keep the COT population levels steady are out of whack, allowing their population to explode to dangerous levels.

From what little I have seen, there is a systematic approach to controlling COT. This is being done by teams of scientists and volunteer divers who are moving through the reef system and taking out all the COT they find. In the video I saw of this the reef was clearly overwhelmed, and 100's were killed in less than an hour.

 

[Gunrock0811]

From what i'v read and watched through discovery/nat geo, the over population of the COT was from over fishing in the area before that basically took out the COT's natural predator. another reason for their overpopulation was due to global warming. temperature in the area is too perfect for them and thanx to all the corals, its basically spawning heaven for the COT.

also, even though there have been groups of ppl and scientists going around killing the COT, the COT multiplies too fast for their efforts to make a dent.

 

[pro99line]

Crown of thorns actually have their place in the reef ecosystem. They keep fast growing corals from smothering slower growing corals and also provide a food source for certain predatory fish, certain shrimp, and even worms.

In the event of an outbreak of them, it is common practice to "extinguish" them though. In large numbers they cause more harm than good.