Date: Mon, 30 Mar 1998 06:57:49 -0500 (EST)
From: JOSHUA Feingold <joshua@polaris.acast.nova.edu>
Subject: Coral Bleaching in the Galapagos Islands

Here's an update to Dr. Wellington's report from December. 
On a recent trip to the Galapagos archipelago Andrew Baker 
and I observed extensive coral bleaching. One benefit was 
that it was extremely easy to see scattered colonies on the 
dark basalt backgrounds, making swimming surveys as 
comprehensive as I have ever experienced. Nearly all corals 
were bleached to some extent. The most strongly affected 
species was Porites lobata followed by Pavona clavus, Pavona 
gigantea and Pavona varians.  Other affected species included 
Psammocora stellata, Diaseris distorta and Cycloseris curvata. 
Interestingly, the genus most impacted during the 1982-83 
ENSO, Pocillopora, seems to be faring quite well. Many 
Pocillopora colonies exhibited normal pigmentation, while 
others showed variable amounts of pigmentation loss. In other 
genera, many colonies exhibited pigment loss on their tops with 
some pigmented tissues still present along their flanks and in 
shaded portions. Psammocora exhibited a range of pigment loss, 
and was one of the few genera to show distinctive paling. Some 
Diaseris individuals (at 15m depth) were completely bleached, 
but many still had pigment remnants in tissues btween septae. 
Most Cycloseris individuals had relatively normal looking 
tissues on their flanks. Bleached corals were observed in water 
depths ranging from the surface to 30m. However, bleaching 
was more extensive in corals shallower than 10-15m depth. A 
follow-up trip is planned for May.

Joshua Feingold
Department of Math, Science and Technology / Oceanographic Center
Nova Southeastern University
Fort Lauderdale, Florida
joshua@polaris.acast.nova.edu