[Coral-List] Thermal stress and bleaching risk spreading in Caribbbean, parts of Pacific
mark.eakin at noaa.gov
Thu Aug 21 15:06:53 EDT 2008
Northern hemisphere waters are continuing to rise and we are starting
to receive reports of bleaching. New graphics have been added with
this week's update to the seasonal forecast.
A reminder of terms from the Coral Reef Watch satellite-based
bleaching alert system:
Bleaching Watch: HotSpot values > 0
Bleaching Warning: HotSpot values > 1, currently accumulating thermal
stress (Degree Heating Weeks)
Some warming has begun across much of the Caribbean and much of the
Caribbean is now under bleaching watch. This broad area of low level
has been consistent with our new seasonal bleaching forecast. We are
now providing access to week-by-week images and animations from the
forecast to help users better understand how the bleaching risk is
likely to change through time.
18 of our 24 Caribbean virtual stations under Bleaching Watch, Lee
Stocking Bahamas under Bleaching Warning and record high temperature:
Flower Garden Banks: Temperatures have cooled and the forecast models
call for further cooling. Hopefully the threat will subside now that
the sun and the greatest heating are heading south.
Florida: Slight cooling in Florida Bay and around the Keys will
hopefully reduce the threat here as well.
Bahamas and Greater Antilles: The warming is moving in this direction
and the forecast calls for continued warming for a few more weeks if
we don't get some tropical storm cooling. The satellite-based
temperature of 31.2 degrees C is the highest we have seen this decade.
Lesser Antilles: The forecast calls for the greatest warming from the
southern coasts of Hispanola and Puerto Rico, south and east through
the Windward Islands to Trinidad. At this point, all of these islands
north of tobago are under a Bleaching Watch and further warming is
expected. Melissa Keyes reported seeing 5-10% paling around St. Croix
Northern Coast of South America: The forecast calls for this area of
greatest warming to include waters off the northern coast of Venezuela
including Los Roques and the ABCs. Much of this area is already under
a Bleaching Watch. The forecast still calls for further warming along
the Colombian coast, much of which is already under a Bleaching Watch.
Central America to Mexico: The forecast models indicate that further
warming will take place, primarily from Nicaragua to Panama. This
region has also warmed during the last week and much is under a
The seasonal outlook calls for very high temperatures and the
potential for severe bleaching around the Baja Peninsula. All of the
southern half of the peninsula is under a Bleaching Watch or Bleaching
Warning and continue to rise.
Bleaching Watch conditions have been reached at about half of the
Northwestern Hawaiian Islands. The forecast calls for further
warming, especially at Midway and beyond, but it is not likely to be
New virtual stations have just gone online for many of the Pacific
islands and reefs at:
Western Pacific/East Asia:
Accumulation of thermal stress continues in earnest around Korea and
southern Japan. Keshavmurthy Shashank reported bleaching in
Nishidomari, Otsuki worse than in 2007. DHW values have exceeded 4 off
most of the main islands of Japan. Thermal stress has begun along the
Ryukyus, but temperatures have varied significantly along the chain --
Okinawa has been under a Bleaching Watch, while temperatures at
Ishigaki are back below the maximum monthly mean. The forecast model
suggests that this warming should subside in the coming weeks. The
forecast calls for the greatest warming in this region to be along the
Northern Mariana Islands and Micronesia and down to Papua-New Guinea.
The islands of FSM west of Chuuk and much of the region around Guam
and CNMI are now under Bleaching Watch or close to the maximum monthly
mean. However, the forecast system does not call for severe bleaching
in this area.
Our new seasonal bleaching outlooks can be found at:
Current HotSpot and Degree Heating Week charts and data formatted for
HDF and Google Earth can be found at:
Time series graphics for index sites can be found at:
You can sign up for automated bleaching alerts at:
Please report bleaching events (or non-events) at:
C. Mark Eakin, Ph.D.
Coordinator, NOAA Coral Reef Watch
National Oceanic and Atmospheric Administration
Center for Satellite Applications and Research
Satellite Oceanography & Climate Division
e-mail: mark.eakin at noaa.gov
E/RA31, SSMC1, Room 5308
1335 East West Highway
Silver Spring, MD 20910-3226
301-713-2857 x109 Fax: 301-713-3136
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