[Coral-List] Grazing vs fertilization

Michael Risk riskmj at univmail.cis.mcmaster.ca
Fri Oct 13 10:22:36 EDT 2006

Hello Andrew.

I have been following this thread with wry amusement, waiting for
SOMEONE to mention bioerosion. It seems the modern coral reef
biological community has a knowledge lacuna. To summarize:

-bioerosion accounts for >50% of the carbonate balance of a reef, and
hence no study that omits this process has a snowball's chance of
understanding reef trajectories. Not a chance.

-rates of bioerosion are directly correlated with water quality, hence
many modern reefs are already in a deficit position.

-the Caribbean has a wonderful bioindicator, Cliona delitrix
(bright-red boring sponge, kills corals, eats fecal bacteria). EVERY
Caribbean monitoring program should include estimates of occurrence of
this sponge, and very few do. (There is a Pacific equivalent, C.
orientalis, but it's sort of a boring brown colour... As far as I am
aware, not a single Pacific monitoring program includes bioerosion

All this has been said before, and has been in the literature for more
than 40 years now. What's wrong with this picture? Why is it so hard to
get this message across?


On Wed, 11 Oct 2006 11:46:41 -0700 (PDT)
 andrew ross <andyroo_of72 at yahoo.com> wrote:
> All,
>   I hear nothing of the double edged sword that is top-down grazing
> in the presence of plenty of nutrient: the boring/ bio-erosion aspect
> of reef dynamics.
>   In terms of overall reef preservation/restoration there is more
> then just top or bottom... It's more of a 3-D set of dramas.
> Even if the grazers turn out to be the great saviors of living,
> growing coral, based on what i see in Montego Bay the reef structure
> is still crumbling from within so long as the water is full of sponge
> food. And the urchins themselves are no angels.
>   My two cents.
>   Andrew 
> DeeVon Quirolo <deevon at bellsouth.net> wrote:
> James---anyone who knows me realizes that the bottom up theories of 
> Dr. Brian Lapointe and others have been endorsed and implemented in 
> Reef Relief's educational programs for the past twenty years......I 
> was just saying that we should all come together and stop the eternal
> dialect of I'm right, you're wrong, when each side is equally sure 
> they are 100% right. We all need to get over that and work together 
> to save the remaining vestiges of reefs. Best, DeeVon
> At 02:39 PM 10/10/2006, Dr. James M Cervino wrote:
> >Dear Ilsa & Devon,
> >
> >Congrats on a thorough well put together manuscript! It is about
> time
> >that these data are beginning to get published, I will use this for
> >my class this next semester.
> >
> >The sad point is that the people that think urchin grazing and other
> >dwindling herbivores/landscapers swimming on reef system control the
> >algal lawns that smother corals. This says to the developers that
> >claim "hey our point source" that is spewing secondary treated
> >sewage out into a reef is not the reason for the reefs to become
> >algal dominated, its because the spiny urchin died off that used to
> >be a proficient landscaper and kept the corals "macro-algae free".
> >
> >Devon what I am not saying that top down controls are not
> >significant, they are. However, what I am trying to say is that the
> >levels of nutrients that induce algal blooms cannot be controlled
> >with more grazers.
> >
> >Cheers, James
> >
> >--
> >**************************************************
> >Dr. James M. Cervino, MS, Ph.D.
> >Marine Pathology
> >Department of Biological & Health Sciences
> >Pace University New York NYC
> >Phone: (917) 620-5287
> >Web site: http://www.globalcoral.org
> >***************************************************
> >_______________________________________________
> >Coral-List mailing list
> >Coral-List at coral.aoml.noaa.gov
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Mike Risk
Marine Ecologist
PO Box 1195
Durham Ontario
N0G 1R0

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