[Coral-List] Potential for severe bleaching in Australia and surrounding areas in 2009
Mark.Eakin at noaa.gov
Tue Jan 6 16:55:50 EST 2009
It's that time of the year again and southern hemisphere waters are
starting to warm for this year's bleaching season. Unfortunately, the
bleaching potential for the Great Barrier Reef is high based on
forecasts and analyses from NOAA and the Australian Government. The
area likely to experience the highest temperature anomalies and
greatest potential for widespread bleaching during the next 12 weeks
is a region extending southeast from Papua New Guinea to the Solomon
Islands, the GBR, and New Caledonia.
Greater Barrier Reef:
Some warming has begun in this region, with HotSpots present for most
reefs of the Great Barrier Reef (GBR) and mild accumulation of thermal
stress (Degree Heating Weeks of around one degree-week) along the reef
from Cairns northward. All of Coral Reef Watch's Virtual Stations for
the GBR reached their warmest month’s average temperature during
December 2008. Recently, local storms cooled the waters along much
of the GBR, but our seasonal bleaching outlook suggests that it is
likely that most of the GBR has the potential to experience moderate
to severe thermal stress by the end of this month. These conditions
are expected to continue through February. Stress levels of the
magnitude shown by the bleaching outlook model are expected to be
similar to those that have caused severe bleaching in the past,
including 2002. It should be noted that the bleaching potential is
expected to peak around mid-February when both the bleaching outlook
model reaches its peak and neap tides are expected along the GBR.
Weak tidal currents limit the cooling of tidal circulation. Observers
already have noted some minor bleaching along the northern GBR.
Ocean temperatures have begun to cool in the Coral Triangle (CT)
region west of Torres Strait as the sun has moved southward. HotSpot
values are diminishing across Indonesia from Borneo to Papua. HotSpot
values are now zero in most of that area, so we do not anticipate any
significant accumulation of thermal stress at this time. This may
change with renewed warming around March.
Thermal stress continues to accumulate just east of Torres Strait
and in the region between Papua-New Guinea and the Solomon Islands.
As warming continues and is expected to expand in the Coral Sea,
thermal stress may continue to accumulate. Reef locations in the east
of the Strait, the eastern-most islands of Papua New Guinea (Venema
and Rossel Islands), and the western side of the southern Solomon
Islands exceed DHW of 4 (Alert Level 1) and continue to warm. The
potential for thermal stress levels that can cause severe bleaching is
expected to continue through February.
Some warming with positive HotSpot values and mild accumulation of
thermal stress has begun along a band from New Caledonia, past Fiji,
to waters south of Raratonga. The bleaching outlook model indicates
that there is a potential for high thermal stress for New Caledonia
and perhaps Fiji and Tonga, with less extreme warming in the southern
Cook Islands and French Polynesia. Warming of waters around New
Caledonia is expected to continue through February; stress levels of
the magnitude shown by the bleaching outlook model are similar to
those that may cause bleaching in New Caledonia.
Some warming with positive HotSpots and mild accumulation of thermal
stress has begun in the western Indian Ocean around Madagascar. The
bleaching outlook model calls for continued low-level thermal stress
until at least the end of the month. The bleaching outlook model also
shows the potential for some warming and threat of mild bleaching
around Madagascar through January and in western Australia in March.
Our 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:
The official coral bleaching forecast and status from the Great
Barrier Reef Marine Park Authority can be found 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 Hwy
Silver Spring, MD 20910-3226
301-713-2857 x109 Fax: 301-713-3136
"Now is the time to confront [the climate change] challenge once and
for all. Delay is no longer an option.
Denial is no longer an acceptable response. The stakes are too high.
The consequences, too serious."
President-Elect Barack Obama, Nov. 18 2008
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