[Coral-List] Do corals need fish to remain healthy?
Eugene Shinn
eshinn at marine.usf.edu
Fri Feb 20 09:53:51 EST 2009
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----------------------------------
-----------------------------------
More information about the Coral-List
mailing list