Julian Sprung's email.

Ove Hoegh-Guldberg oveh at uq.edu.au
Sat Aug 26 00:37:21 EDT 2000

Flow probably has some effect through the removal of some of the feedback effects of the high oxygen
tensions that occur during the daylight hours.  If the increased production of active oxygen after
thermal stress (a'la Jones et al 1998, reviewed in Hoegh-Guldberg 1999), then flow might have an
ameliorating effect through the decreased boundary layer thickness and hence oxygen tensions close
to coral surfaces.

Survival near rivers might be related to the decreased light stress due to the higher turbidity of

Just some ideas ...



Professor Ove Hoegh-Guldberg
Director, Centre for Marine Studies
University of Queensland
St Lucia, 4072, QLD

Director, Heron, Stradborke and Low Isles Research Stations
President, Australian Coral Reef Society

Phone:  +61 07 3365 4333
Fax:       +61 07 3365 4755
Email:    oveh at uq.edu.au

-----Original Message-----
From: owner-coral-list at coral.aoml.noaa.gov
[mailto:owner-coral-list at coral.aoml.noaa.gov]On Behalf Of Bruce Carlson
Sent: Saturday, 26 August 2000 4:15 AM
To: Bernard A. Thomassin; coral-list at coral.aoml.noaa.gov
Subject: Re: Julian Sprung's email.


Did you also notice that corals in areas with swift flowing water (usually
from tides) also survived better than nearby reefs with low flows?  I
noticed this in Fiji on the shallow barrier reef of the University of the
South Pacific, and in Palau near the lighthouse reef -- both are similar
reef environments with strong laminar water flow (the water is shallow
enough to stand up at mid-tide, but the current knocks you over -- I don't
have a more precise current measurement).  Why would flow rate matter?
Perhaps there is something related to diffusion rates (which would increase
in strong water flow) which offers some protection during bleaching????  If
Ove is right about superoxides forming during warm water events, maybe this
observation is relevant.

Also, in Fiji, we noticed that reefs near river mouths also showed good
survival rates.  The outer barrier reefs in Palau and Fiji seemed to be hit
the hardest.


----- Original Message -----
From: Bernard A. Thomassin <thomassi at com.univ-mrs.fr>
To: <coral-list at coral.aoml.noaa.gov>
Sent: Friday, August 25, 2000 6:30 AM
Subject: Re: Julian Sprung's email.

> Jonathan.Kelsey at noaa.gov wrote :
> >-Are these generally accepted concepts?
> >-Can one accurately assess coral mortality rates associated with a
> >event after "a matter of just a few days"?
> >-Are there quantitative studies showing that there is a greater bleaching
> >survival rate among corals in polluted waters versus those in
> >water? -Any comments and/or further discussion would be greatly
> We will presented a poste about the subject at bali meeting. In Mayotte
> Is., North Mozambique Channel, a huge bleaching occurred in 1998 spring
> (end of summer season there) and most of 90 percent of the shallow coral
> the barrier reefs died.
> Those corals that surveyed the best are from the muddy environnements in
> bays, on fringing reef fronts and patches, even the harbour !why ? Because
> the corals living in oceanic cooler waters of the barrier reef belt (170
> long) are less adapted to tolerate hot waters and high level of light
> got "sun burns" as table acroporas). In opposite population of corals
> species) living in neritic coastal waters, in inner areas of the lagoon,
> are genetically more adapted to tolerate : high temperature, turbid waters
> after rainfalls, even falls of salinity. Today in Mayotte, probably the
> recovering ibn coral of the mid-lagoon patch reefs (recruitement) is due
> larvae coming from these coastal coral populations. These is one of the
> main reasons to protect these "special" reefs in muddy environments from
> all the effects of coastal works (marinas, dredgings, infilling of
> for roads, etc...).
> This is a good way for researches.. and from where larvae that recruit are
> coming.
> Bernard A. Thomassin
> Directeur de recherches au C.N.R.S.
> G.I.S. "Lag-May"
> (Groupement d'Int=E9r=EAt Scientifique Environnement marin et littoral de
> Mayotte")
> & Centre d'Oceanologie de Marseille,
> Station Marine d'Endoume,
> rue de la Batterie des Lions,
> 13007 Marseille
> 9l. (33) 04 91 0416 17
> 9l. GSM 06 63 14 91 78
> fax. (33) 04 91 04 16 35 (0 l'attention de...)
> e-mail : thomassi at sme.com.univ-mrs.fr

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