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archman:Weeeell... Cozumel reefs have a tendency to stay healthier than most other regions of the Caribbean, but the area does get mass bleaching events. 1989 and 1995 were particularly severe on the local reefs. The 1997-98 El Nino problems somehow avoided Cozumel. To quote Napoleon Dynamite, "LUCKEEEEE!"
Bleaching is usually related to water temperature. Cozumel reefs get all jacked up when it gets too hot, just like other reefs. The 2005 mean summer temps around Cozumel were much cooler than that for the parboiled eastern Caribbean, which explains a lot.
Scientists don't really survey Cozumel reefs much. Hardly at all, actually. Thus the public often synonymizes a lack of coral reporting to mean the same thing as the reefs being healthy. However, historical comparison studies by Goreau (a leading coral dude) have shown otherwise. It's the very devil to track down this research. There's some nice stuff about white plague on Cozumel corals.
http://www.globalcoral.org/Dolphin enclosures and algae distributions at Chankanaab, Co.htm
The reefs are still in better shape than most other places in the Caribbean. And americans really can't beat the prices either.
Regarding 2005 bleaching damage for the area, I haven't read anything but anecdotal or amateur accounts. Usually it takes at least a year before final reports are completed. I haven't seen anything on NOAA's coral researcher listserv regarding hurricane wilma. Not one peep. Which either means nobody's done any surveys, the research is still being worked up, or the researchers aren't on the listserv. EVERYBODY'S on the listserv.
archman:One normally doesn't see much (new) bleaching in the winter months. Folks that perform coral surveys during this time tend to be either:
1. Establishing a pre-summer baseline
2. Late in surveying from last summer
3. Testing hypotheses for less common bleaching factors (i.e. runoff, disease)
4. Diving in the winter because it's the only time they're available
#4 is pretty common. Hurricanes screw up a lot of scientists' schedules.