[Coral-List] Coral-List Digest, Vol 48, Issue 17

[Austin Bowden-Kerby Travelling]

Hi Todd (and Andrew), 
 
I have been working with Acropora and Coraliophila snails and Hermodice fire worms for a long time in DR and Honduras and formerly in PR and Jamaica.  Todd, for the sake of the corals, please remove all snails (and worms) from the Acropora colonies when you find them in your work, as a dozen or so snails will kill even a large colony in only a few months, and these corals are truly precious and as you know are mostly either gone or are still in the process of declining.  
 
Regarding your question- my experience is that spreading out the coral transplants is not always the best strategy, unless you have someone to do regular and frequent "coral gardening" - removal of snails and fire worms and the occasional weeding of seaweeds.  If there are a lot of snails around on other corals, spreading them out may end up increasing the predation problem, but if the reef is mostly devoid of other corals, then spreading them out may work fine.  The snails live on all sorts of corals (they love to lurk around the edges of brain corals and on Montastrea, and when very small they seem to prefer Agaricia), but they don't seem to be as devastating to those species with thicker flesh.  However they seem to much prefer Acropora, and so if you spread your transplants out, the corals will almost for sure be attacked, as the snails leave the corals they are on and go for their preferred Acropora.  Probably the most important thing that we have found is that the
 snails do not like to cross sand, so a better strategy is is to locate a reef spur surrounded by sand channels or a small patch reef on which to focus your restoration work, removing any snails you can find on other corals initially, but with the understanding that once the snails are under control, that new snails will not be able to readily move in from the surrounding reefs, although sometimes some very tiny ones appear later on, apparently settling out of the plankton.  Fire worms will cross sand, so it is only a partial barrier, so the corals still need to be monitored for predators, but not as frequently.  Reef balls on sand should also work very well as Acropora nurseries!   It is my hypothesis that a lack of lobsters and trigger fish are the most important factors in the Coraliophila snail (and perhaps Hermodice fire worm problem).   While trigger fish seem to effective controls on snail outbreaks on Acropora palmata, they don't seem to be as effective in
 controlling the snails on A. cervicornis, perhaps due to the species' branchiness.   What this tells us is that no-take MPAs are the foundation of coral reef restoration- otherwise we are fooling ourselves.  I believe that coral predation may have been underestimated as a primary factor in the demise of both species of Acropora, as it is quite easy to attribute fresh coral predation to coral disease (WBD).  I have found that in all of our sites in all of the countries where we have worked over the past several years that predation is presently by far a much more severe problem for Acropora than coral disease is.  If there is a problem with disease, it is sporadic, and often secondary to Stegastes damsel fish infestation (secondary to overfishing of groupers?) or to land based development and dirty water- so if possible stick to clean waters and avoid areas with these damsel fish.  Based on Andrew's posting Hermodice fire worms may also be a vector for disease.... from what
 I have read, this has already been established for Coraliophila snails.
 
I plan to get all of these and other findings and suggestions/opinions out in an Acropora restoration handbook in the coming year or so. 
 
Regards,
 
Austin
 
 
Austin Bowden-Kerby, PhD
Coral Gardens-Living Reefs
Counterpart International
Suva, Fiji; (679)331-3377 
 
www.counterpart.org 


Message: 3
Date: Tue, 19 Jun 2007 15:11:50 -0400
From: "Todd Barber" <reefball at reefball.com>
Subject: [Coral-List] Acropora palmata (Elkhorn Coral) Recovery After
    Hurricanes-coralivorus snails
To: <coral-list at coral.aoml.noaa.gov>
Message-ID: <026701c7b2a5$b0c7f1b0$6501a8c0 at reef8c359cb049>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
    reply-type=original

Hi All,

We conducted a coral propagation and planting training program for the 
National Marine Park(s) of Cozumel (and Cancun) last week in Cozumel.  As 
part of the project, we surveyed the Dzu Ha beach area and only found one 
acropora palmata colony in an area with many dead stands of acropora palmata 
skeletons.  It was under heavy attack by coralivorus snails and looked in 
rough shape.  In was not in a condition to provide stock for coral 
propagation and planting.  Therefore we searched the whole south coast of 
Cozumel along with knowledgable park staff and only found 9 additional 
colonies.  We propagated and planted 32 fragments of the colony that 
exhibited the least number of coralvorus snails.

We spread these colonies widely in the immeadiate area of the original 
colony under attack.  Our hope is to recover many colonies but at a minimum 
to spread out the coralvorus attack taking pressure off the remaining adult 
colony.

My question is if anyone has done studies on coralivorus snails and Acropora 
palmata who might have some advise for us in this situation.  We would like 
to attempt a complete genetic rescue of all 9 original colonies but we don't 
want to risk propagation stress without fully understanding the implications 
of higher than normal coralivorus snail concentrations as a result of the 
hurricane.


Thanks,

Todd R. Barber
Chairman, Reef Ball Foundation
3305 Edwards Court,
Greenville, NC 27858
941-720-7549 Cell
252-353-9094 Direct
Skype Toddbarber or Skype In (252) 557-1047, United States (+1)
MSN messenger reefball at hotmail.com
reefball at reefball.com (email address) 



Message: 5
Date: Wed, 20 Jun 2007 07:42:01 -0700 (PDT)
From: andrew ross <andyroo_of72 at yahoo.com>
Subject: [Coral-List] Coral disease- tissue sloughing
To: coral-list at coral.aoml.noaa.gov
Message-ID: <139899.90748.qm at web50606.mail.re2.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1

List,

For the past 2 weeks i've been seeing tissue sloughing
on M. annularis and A. cervicornis seemingly
associated with recent heavy rain in Montego Bay,
Jamaica. I wave my hand over the coral and tissue
comes away in small (or sometimes not so small)
sheets.

On A. cervicornis this is directly associated with
Hermodice (fire worm)attack- only affects
attacked/bitten corals to continue to kill more/all
tissue over a few days. Associated with (probably) one
'tainted' worm as all are in one re-planting plot area
and bites of similar size. Unbitten corals within same
plot remain healthy.

Andrew


       
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