Marshall Island Bleaching

[John Naughton]

I just returned from two weeks of extensive coral reef surveys at
Kwajalein Atoll in the Marshall Islands.  Our surveys concentrated in the
northern part of the atoll (basing out of Roi-Namur) and the eastern or
windward reefs.  We also recorded extensive bleaching of the top 8 to10
inches of many species in shallow water.  However, we believe the
bleaching was due to a series of very low tides coupled with light winds
and periods of heavy rain.  Hopefully most colonies will recover rapidly
with the return of more normal conditions.

Aloha,       John

John Naughton
Pacific Islands Environmental Coordinator
National Marine Fisheries Service, NOAA
Honolulu, Hawaii

Clive Wilkinson wrote:

> >Date: Tue, 10 Sep 2002 17:23:07 -0700 (PDT)
> >From: Dean Jacobson <atolldino at yahoo.com>
> >Subject: Marshall Island Bleaching
> >To: c.wilkinson at aims.gov.au
> >X-Scanned-By: MIMEDefang 2.6 (www dot roaringpenguin dot com slash
> mimedefang)
> >
> >Greetings:
> >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.
> >
> >Cheers,
> >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
> >http://dir.remember.yahoo.com/tribute
> >
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