[Coral-List] Request information on bleaching or no-bleaching from Okinawa, Japan

Gang Liu Gang.Liu at noaa.gov
Fri Sep 12 12:43:52 EDT 2003

Our satellite coral bleaching HotSpot charts show that thermal stress,
conducive to coral bleaching, started developing in the northwest
Pacific Ocean in late June.

Bleaching HotSpots started to appear in Okinawa region in mid-July
and continued to develop until early August
when the region was struck by two typhoons (Typhoon 10 around Aug 8 and
Typhoon 11 around Aug 18-19).

By the time the typhoons hit, DHWs had accumulated to around 4 (DHW) and
above at Okinawa and around 8 and above to the east in the open ocean.
Seeing this magnitude of accumulated thermal stress we feel that coral
bleaching most likely occurred in the Okinawa region prior to the
typhoons (these cyclones naturally cooled the water significantly).

However, it can be seen that bleaching HotSpots did return to Okinawa
region in between the two typhoons
and even after the second typhoon in late August
Bleaching HotSpots are still lingering in this area although they are
not as significant as before the typhoons.

The breaks from elevated HotSpot levels appear to have been about one
week each and two weeks in total during a time period of about 2-month
from initiation of HotSpot levels to present. Sea surface temperature
decreased significantly during each break. It would be interesting to
learn if there is any new bleaching caused by the accumulative effect of
the thermal stress over the whole summer period even with two cold water
breaks in between. Some isolated small-scale anomalous hot water pockets
which develop only after the typhoons and are not always detected by our
50km satellite product may have been present and possibly might have
induced additional bleaching.

Any feedback on the bleaching information in the region, both bleaching
and no-bleaching observations, will be highly appreciated.


Please send the feedback to Alan Strong (Alan.E.Strong at noaa.gov)  and/or
Gang Liu (Gang.Liu at noaa.gov) - NOAA’s Coral Reef Watch Program.

Users are also encouraged to use the NOAA/ReefBase collaborative online
bleaching report form to send input to our bleaching database. Both
bleaching and no-bleaching observations are desired. The form is
available at


Coral Reef Watch Program

 Gang Liu, Ph.D.
 Senior Research Scientist/Oceanographer
 (Decision Systems Technologies, Inc.)
 NOAA Coral Reef Watch Program
 SSMC1, #5307
 1335 East-West Highway
 Silver Spring, MD 20910-3226

 Tel: 301-713-9386 ext 131
 Fax: 301-713-3136
 Email: Gang.Liu at noaa.gov

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