Coral Bleaching in the Galapagos Islands

[JOSHUA Feingold]

Dear List Members,

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.

Sincerely,

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