[Coral-List] Large Area of Potential Bleaching - Cape Verde/Canaries

Alan E. Strong Alan.E.Strong at noaa.gov
Thu Oct 26 09:20:31 EDT 2006

A large area of warm water has developed over the past month around the 
Cape Verde Islands.  Over the past few weeks it has evolved toward the 
north and now encompasses much of the Canary Islands. It has developed 
with a similar shape and timing as the 2001 bleaching event in that 
location off Africa but appears a bit stronger this year than in 2001. 
Degree Heating Week [DHW] levels have reached 9 to 11 in the Cape 
Verdes, particularly on the north side of Sal and Santa Luzia and 
southern shores of Fogo & Brava.  In the Canaries the most extreme 
temperatures stresses (DHWs) appear to exist in the waters between 
Fuerteventura and Gran Canaria where DHWs of 7 to 8 are presently 
observed.  If we were providing alerts for this location we would be 
noting that SSTs at this level of accumulations would most likely be 
indicative of widespread bleaching at these locations. 

Empirical evidence has shown that a DHWs of 4 or greater (e.g., 4 weeks 
with 1 degree C above threshold) usually returns mild to significant 
coral bleaching and DHW of 8 or greater indicates widespread bleaching 
and some mortality. 

 As previously indicated, the Caribbean 2006 event appears to have 
peaked and presently is winding down with highest levels being shown 
this year around the northern Lesser Antilles where DHWs barely reached 
5 in a few locations.

In the central Pacific, the waters around the Kiribatias continue to 
show quite high DHW levels (DHW = 13 just north of Nikunau - 
177E/Equator) and SSTs surrounding Howland/Baker, 15 degrees of 
longitude to the east, have reached DHW levels of 9-10.

Our 24 index sites around the globe can be found at:

Current HotSpot and Degree Heating Week charts, HDF data, and 
GoogleEarth products can be found at:

Please reporting any bleaching events (or non-events) at:

**** <>< ******* <>< ******* <>< ******* <>< ******* 
Alan E. Strong, Ph.D.
NOAA Coral Reef Watch, Senior Consultant
National Oceanic and Atmospheric Administration
NOAA Coral Reef Watch Program
  e-mail: Alan.E.Strong at noaa.gov
url: coralreefwatch.noaa.gov

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