[Coral-List] Do corals need fish to remain healthy?

Szmant, Alina szmanta at uncw.edu
Fri Feb 20 11:23:57 EST 2009

Hi Gene:

I have been to Smith Bank on the S side of Roatan with the incredible A cervicornis patch a number of times, and have plenty of photo and video documentation.  Harold must not have been paying attention because the place is crawling with both 3-spot damsels and lots and lots of parrotfishes (smaller sizes of course).  Roatan has large schools of grazing/roving surgeon fishes and doctor fishes.  And I have seen large schools of blue parrot fishes as well.  Thus while this may have nothing to do with why this substantial patch of A cervicornis is there, it is incorrect to state there it's there without fishes.  I'd attach photos if Coral-List allowed and don't have time just now to post any photos or video to my web page.

My concern about this particular site is that it is fairly close to shore and right next to a shipping channel used by large cruise ships, and a new cruise ship dock has just been built near it.  It could all be gone with one steering mishap.  Someone/some organization needs to step in to somehow better mark it and make sure it does not get flattened.

There is a similarly impressive stand of A palmata in the Rincon are of Puerto Rico, and it is alive and will with big schools of grazers.  There are lots of sexual recruits at this site.  It is a protected area near a beach, and the biggest threat is unbridled major development and sediment near the site.



Dr. Alina M. Szmant
Coral Reef Research Group
UNCW-Center for Marine Science
5600 Marvin K. Moss Ln
Wilmington NC 28409
Tel: (910)962-2362 & Fax:  (910)962-2410
Cell:  (910)200-3913
email:  szmanta at uncw.edu
Web Page:  http://people.uncw.edu/szmanta
-----Original Message-----
From: coral-list-bounces at coral.aoml.noaa.gov [mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Eugene Shinn
Sent: Friday, February 20, 2009 9:54 AM
To: coral-list at coral.aoml.noaa.gov
Subject: [Coral-List] Do corals need fish to remain healthy?

Bill Precht, Program Manager at the Florida Keys National Marine
Sanctuary  recently made me aware of a new paper titled, "Macroalgae
Has No Effect on the Severity and Dynamics of Caribbean Yellow Band
Disease." Ivana Vu et. al, 2009, published in PloS Feb 09 Vol 4 Issue
2. The paper is the result of an ingenious  manipulative field study
in Puerto Rico. As the title implies it shows, that various
Macroalgae have no effect on CYBD in Montastraea faveolata . This
conclusion contradicts the widely repeated mantra that these algae
stimulate coral disease by serving as a reservoirs of pathogens  and
that their proliferation on reefs is due to removal of herbivorous
fishes. In other words, remove fish (overfishing) that eat algae and
the algae will grow and cause decline of coral.
When I read the paper I was reminded of a recent conversation with
Harold Hudson of Reef Tech  who described to me what he recently saw
in Roatan. "It was the biggest healthiest staghorn coral forest I
have seen in many years", he said.  What caught his eye also was that
there were essentially no fish! Not even the ubiquitous Damsel fish
that normally thrive among staghorn branches. It was wonderful to
hear that such healthy staghorn fields still exist but isn't it odd
that it is thriving  without the usual tropicals, surgeon, and parrot
fish? Similar observations have been recorded by J. Keck et al.,
"Unexpectedly high cover of Acropora cervicornis on offshore reefs in
Rotan (Honduras)" published in Coral Reefs, DOI
10.1007/s00338-005-0502-6  and also confirmed in a paper by B. Riegl
et al, Offshore refuge and metapopulation resilience explains high
local densisty of an endangered coral (Acropora cervicornis). In
Marine Pollution Bulletin.  Many of us can remember the luxurious
corals on the North coast of Jamaica before the early 1980s at a time
when the area had already been fished out. Apparently what ever
started the general Caribbean decline in the late 1970s and early
1980s remains  somewhat elusive but widespread.  I suggest we need
more straight-forward in-the-field experiments such as the Puerto
Rico study cited at the beginning.  May be we should  rethink the
commonly cited association between fishing and coral health??  Gene

No Rocks, No Water, No Ecosystem (EAS)
------------------------------------ -----------------------------------
E. A. Shinn, Courtesy Professor
University of South Florida
Marine Science Center (room 204)
140 Seventh Avenue South
St. Petersburg, FL 33701
<eshinn at marine.usf.edu>
Tel 727 553-1158----------------------------------
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