[Coral-List] Responding to Coral Bleaching
tim at atolleditions.com.au
Mon Sep 21 08:56:51 EDT 2015
There are around four Stegastes damselfish in the Maldives, of which two species Stegastes nigricans and Stegastes lividus – both widespread Indo-Pacific species – appear to be the most common.
I'm not sure how many species occur elsewhere, or their abundance, but if I had to choose representative species to monitor across the entire Indo-Pacific, it would be these two. Would you agree?
What about the other farmer damsels, the Plectroglyphidodon? Plectroglyphidodon lacrymatus and Plectroglyphidodon dickii are two of the five common Maldives, widespread Indo-Pacific species. From your experience, are these as equally aggressive in attacking COTS?
Is there any benefit to be gained by widespread Indo-Pacific monitoring of representative fish species, such as the Stegastes, as a comparative COTS study before, during and after outbreaks?
I ask this because if controlling COTS outbreaks means involving the wider community for assistance, involvement can be made more enticing by providing interesting and stimulating engagement in monitoring activities.
I also adhere to the KISS principle, Keep it Simple Sid (as well as Keep it Sexy Sid!)
that are absolutely essential in the post-bleaching survival of
On 19 Sep 2015, at 18:12, Austin Bowden-Kerby wrote:
> Bula Dennis and others on the list,
> Interesting observations, many of which have good merit. However, I find
> that a paralysis of will can sometimes be the result of too much side
> thinking and doubting. This massive bleaching will come and then it will
> go very quickly, and it may not return for five years or a decade or so, so
> study it now or perhaps lose the chance- none of us are getting any
> The point I have tried to make is that we have an urgent situation at hand
> that threatens coral reefs NOW. If this were a climate change event
> occurring ten thousand years ago when human impacts were insignificant,
> coral reefs would be ecologically balanced and certainly better capable of
> adapting. But from what I have experienced, every reef is more or less
> under some sort of human-induced stress that makes adaptation to climate
> change much more difficult. I am proposing a completely new strategy that
> gives people something to actually do about bleaching over the short term.
> I have seen that it can make a very big difference.
> Most of the adaptive potential of coral species to beaching rests with the
> bleaching resistant coral colonies, but adaptation is for the most part
> (based on my own experience), being prevented by over-abundance of coral
> predators on reefs, which so often kill most of the surviving corals. This
> is a testable hypothesis that could be an important part of the salvation
> of coral reefs. Predator removal during and after bleaching also gives
> conservationists and activists something to do to fight back, rather than
> sitting on their butts and becoming depressed because there is nothing they
> can do. People desperately need hope at this time, otherwise they may just
> give up on coral reefs.
> I am simply suggesting that for those who live near coral reefs, that they
> might focus on what happens subsequently to a massive die off of
> susceptible corals, knowing that the surviving resilient corals must
> survive in order for the coral reefs to adapt to the new stressors.
> Wherever 80-95% of the corals end up dead, high background numbers of COTS
> and snails etc. seem to prevail nearly everywhere, and these predators have
> the potential to kill everything (palatable) that survives the bleaching.
> Ironically for Pacific reefs, in my experience, it is the Stegastes
> damselfish that are absolutely essential in the post-bleaching survival of
> corals- on many reefs their territories are the ONLY place where any
> Acropora or Pocillopora will escape the COTS. They actively attack the
> COTS and drive them away, as if the COTS were invading sea urchins trying
> to steal their algae. Another easily tested hypothesis, although there is
> an older paper documenting this behavior from Pacific Panama.
> In the Caribbean, I have found that snails and fire worms rarely kill an
> entire colony, and when they do it may take weeks for them to finish the
> job. However, in the Pacific, a single COTS will kill a fist-sized or
> plate-sized piece of coral every day/night, and will normally kill entire
> colonies before moving on. They can also form fronts and kill every
> coral that is tasty to them. It is fairly safe to postulate that if we
> remove a thousand COTS, that we have saved roughly 300,000 corals per year
> for several years. Therefore, COTS removal can be very effective as even a
> one-off intervention to help deal with this emergency. We have an
> opportunity to protect and nurture pockets of reef and to encourage
> accelerated recovery. The development of resilience to future bleaching
> events will then occur, as these pockets of health end up becoming filled
> with thermally adapted corals. Of course the bigger picture issues must be
> dealt with as well, but this approach can reinforce and support MPAs,
> because without corals MPAs function poorly.
> Whether COTS removal is an effective long-term strategy under normal
> conditions was not my point of discussion. We sometimes do it for
> community involvement as much as to save corals. Of course no-take MPAs
> and nutrient control are better long-term solutions that address the root
> causes of predator over-abundance, but you have to have a strategy to get
> fishing community support, and this type of activity builds support
> while offering a very real short-term solution to increase coral cover and
> fish habitat, as Janis and Brooks and many others will testify.
> Again, my original point is that we have an opportunity to act NOW, and so
> I shared a new idea that has potential to motivate communities, NGOs, and
> hopefully scientists, and that helps give the surviving corals a future and
> the people involved more hope. The key element of the strategy is to keep
> the precious corals that survive alive even after the bleaching abates, and
> by whatever means that are at our disposal. This will include predator
> removal and the collection and propagation of corals that thrive in spite
> of hot water and post-stress disease.
> Shouldn't we protect these survivors like we would precious gold and
> diamonds? We put our precious cash and heirlooms into secure banks, and so
> why not create secure "gene bank nurseries" for cultivating resilient
> corals (temperature, disease, etc.). This is exactly what we have done in
> Belize and the Dominican Republic, and we are then using second generation
> fragments trimmed from the nurseries, to restore coral cover to rather
> sizable patches within no-take MPAs where the Acropora corals have not
> returned in spite of other types of management.
> We did all of this in spite of opposition from certain of you within the
> coral reef research community, who went so far as to publish a formal
> position paper that dismissed our efforts, based on incorrect assumptions
> about what we were actually doing. Of course the opposition made it very
> difficult to access funding. I hope that our ultimate success has now made
> it clear that certainly there is room for every approach.
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