[Coral-List] Bleaching update - West coat of Puerto Rico

Ernesto Weil eweil at caribe.net
Mon Sep 20 10:19:25 EDT 2010

Dear listers,

We went  diving last Friday to check bleaching signs is several reef sites
around La Parguera, southwest coast of Puerto Rico. There were bleached
colonies in all 6 reefs checked. Several colonies of the most susceptible
species were  already white.  The most affected species is the zoanthid
Palythoa caribaeorum, with most colonies showing signs of bleaching. This
species however bleaches almost every year.  Few colonies of the crustose
octocorals Erythropodium caribbaeorum and Briaeorun asbestinum also showed
bleaching signs. Within the corals, the  Agaricia agaricites species complex
(A. agaricites, A. humilis, A. danae, A. purpurea) was the most affected
with most colonies highly bleached in shallow habitats and few bleached and
pale colonies in deeper (15-20m) habitats. Several large colonies of
Colpophyllia natans and Siderastrea siderea between 6 an 12 m  were fully
bleached (White and blue respectively)   and several more were pale and/or
showing patchy white areas. Small colonies of  Porites porites  and P.
divaricata, and a large number of colonies of  P astreoides were totally
white. Few colonies of Stephanocoenia intersepta in deeper habitats showed
paling and bleached patches. Only broken fragments of  Millepora lying flat
on the bottom were bleached. All the standing colonies observed have not
bleached . Within the Montastraea group, both M. faveolata and M. franksi
had several (less than 10% of the observed colonies) paling colonies and
colonies with white patches and/or pale patches Neither species had totally
white colonies. Several knobs of  M. annularis however, were bleached white.
No colony of M. cavernosa showed bleaching signs. Within the branching
octocorals, only Pseudoplexaura porosa and Plexaurella nutans had a couple
of bleached colonies. We also observed a few corallimorpharinas withat were

Water temperatures were around 29.7 celcius at 12 noon from 5m all the way
down to 20 m. Surface water temp. was 30.5 celcius. Wind was from the west
and water clarity had improved during the last days due to lack of rain in
the area. We'll check the deep bank reefs at the shelf edge and other reefs
around La Parguera this week.


Dr. Ernesto Weil
Dept. of Marine Sciences
University of Puerto Rico
PO BOX 9000
Mayaguez, PR 00981
(787)899-2048 (x.241)
787-899-5500 (fax)

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