Marshall Island Bleaching

Jamie Oliver j.oliver at
Thu Sep 12 05:08:36 EDT 2002

Dear Dean & Clive

Thanks for submitting this bleaching report to the list. For your
information, and for coral- listers generally, ReefBase keeps an up-to date
database of all bleaching records submitted to us via our on-line report or
to the coral-list. We usually put any new records up within a day or so of
the report being posted and the Marshall Island data is now online.  You can
get a list of bleaching reports by country, or by selecting specific
criteria using a query box
 All new records are also made available in map format on our online GIS
(updated every Friday). We now have over 2,600 bleaching records online.

In submitting a report we ask that people provide as much information as
possible. Our online report form prompts users for basic data on the first
page, and more details (optional) on subsequent pages. If you post your
report to the list, we will extract the relevant information and put in onto
ReefBase, but we would appreciate it if people can provide the minimum data
listed below.

Date: date bleaching was observed, or time of peak bleaching if observed
over a period of time
Location:  place name of the observation- if you don't have lat / long data
(see below) then please provide sufficient details for us to find the place
on a map and insert approximate lat and long
Country:  country name
Lat and Long: - if available, in decimal degrees (this is essential in order
for us to plot the observation on our GIS maps. If you don't supply this, we
will create an approximate lat/long based on the place name you provide
Bleaching Severity: overall intensity of bleaching in the area surveyed
(this can be an estimate). We code all observations into 4 categories - No
Bleaching, Low Bleaching, Moderate Bleaching, High Bleaching
Bleaching Notes:  Any comments on the bleaching not included in other

Additional, highly desirable information which we put on the summary
database includes:

Depth: depth (or depth range) of observations
Temperature: any temperature information, including qualitative notes on
unusually warm conditions
% affected:  estimated (or measured) % of all coral cover in the area that
was bleached - can be a range estimate
Species and Families affected:  list the top 5 or so species or groups which
were most affected by bleaching
Duration: Time period over which bleaching has been observed
Other factors:  Any other factors which may have induced bleaching (e.g.
high light, freshwater, calm weather etc)
Mortality Extent: level of mortality due to bleaching (0=none;1=low;
2=medium; 3=high)
Mortality Notes: general observation on mortality associated with bleaching
Recovery Extent: level of recovery of bleached corals (0=none;1=low;
2=medium; 3=high)
Recovery Notes: general notes on the degree and pattern of recovery of
bleached corals

We have also recently uploaded 27 new records on coral bleaching (or absence
of bleaching) for American Samoa from March this year.  Thanks to Alison
Green for providing this data.

In addition to bleaching data, we welcome images of bleached reefs and
bleached corals - they can be uploaded directly from our user-input area.

Best Regards

Jamie Oliver

ReefBase is a project of the International Coral Reef Action Network (ICRAN)
Jamie Oliver
Senior Scientist (Coral Reef Projects)
ICLARM - The World Fish Center
PO Box 500, Penang 10670

Phone: (604) 626 1606
Fax: (604) 626 5530

email:  J.Oliver at

visit ReefBase on:

 -----Original Message-----
From:   owner-coral-list at
[mailto:owner-coral-list at]  On Behalf Of Clive Wilkinson
Sent:   Wednesday, 11 September 2002 8:08 PM
To:     coral-list at
Subject:        Marshall Island Bleaching

>Date: Tue, 10 Sep 2002 17:23:07 -0700 (PDT)
>From: Dean Jacobson <atolldino at>
>Subject: Marshall Island Bleaching
>To: c.wilkinson at
>X-Scanned-By: MIMEDefang 2.6 (www dot roaringpenguin dot com slash
>I tried to submit a report to the NOAA website, but no
>joy.  Perhaps you could forward this report to any
>other interested parties.
>Coral bleaching, appears to have occured in Majuro,
>the capital of the Marshall Islands, for the first
>time.  This is of consern since the coral reefs here
>are very healthy (except where pollution is
>concentrated) and previously unaffected by bleaching.
>This event is restricted to a very shallow
>near-surface layer, and was first noticed on Sept 6
>(it probably appeared a few days earlier)following the
>observation of an unusually warm surface layer (only a
>meter or less deep)in the Majuro lagoon on Sept 4 (at
>which time no bleaching was yet observed). This
>surface water felt unconfrontably warm, almost hot, to
>an acclimated swimer.
>Later during the weekend I explored Majuro's SE ocean
>shore, and again found bleaching only of the most
>shallow corals (and intertidal zooanthids), along an 8
>mile stretch.  I would guess the entire atoll has
>experienced bleaching (the northern shore has not been
>sampled).  Local residents who were gleaning during
>the low tide report that they have never before
>witnessed this phenomenona.
>Much of the bleached coral emerged during the
>unusually low tides of Sept 9 and 10, but the
>bleaching clearly appears to have begun earlier, while
>completely emmersed.  We had very still, hot weather
>on Sept 1.  Further, the easterlies have been more
>active and consistant then the year earlier.  I
>suspect that a warm water mass was advected into our
>region during this event.
>Species affected include the uppermost intertidal
>Acropora (blue axial tips, A. seriata?) comingled with
>a rose-colored pocillopora, which also has bleached.
>Tip bleaching, marking the shallow thermocline below
>the shallow layer of warm water was found in Acropora
>nobilis and our large pale-margined Pocillopora sp.
>I am photo-documenting selected colonies at a site in
>my back yard (ocean side rock quarry pool), and will
>be monitoring their progress in coming weeks.
>Dean Jacobson, Ph.D., instructor of Marine Science at
>the College of the Marshall Islands and
>Board member of a new NGO: NCCMI, Nature Conservation
>Communities of the Marshall Islands.
>Yahoo! - We Remember
>9-11: A tribute to the more than 3,000 lives lost
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