[Coral-List] Ideal Temperatures for Coral growth, reproduction, and thermal lethal limits.

[Capman, William]

Rudy,

I hesitate to reply here because there are others here with much more
expertise than me, but here is a bit of information.

My understanding is that a lot of these corals grow faster at higher
temperatures, right about up to the temperatures that make them seriously
ill.  The transition between temperatures that give healthy fast growth and
seriously stressful situations can be fairly abrupt.  (Others here can
probably provide more expert knowledge on this).

I have kept a variety of Indopacific corals and such (stony corals, soft
corals, zooanthids, gorgonians, and two species of large anemone) and a few
Caribbean species in reef aquaria for close to 15 years, and have had a few
temperature disasters or near disasters.  Anecdotally, temperatures of
about 80 - 82 or degrees or so have been just fine.  85 degrees F or so has
generally caused some problems, particularly if such temperatures last for
any extended period of time - some species will be fine and others will
show moderate bleaching, while some will die if these temperatures last for
more than a day or a few.

I had one disastrous event where temperatures reached 92 degrees F in one
of my tanks.  I totally lost some large 10 year old colonies of Acropora,
Seriatopora, Pocillopora, and a few others, along with moderate bleaching
or other signs of severe stress in some other species.  Several corals
(including a brain coral that I think is in the genus Symphylia) came
through the whole event just fine, and was seemingly unfazed but the whole
situation.

Clearly, stressful or lethal temperatures vary from one species to the
next, and surely from one location in the wild to the next (and thus for
different populations of a given species).   But in general, a lot of
corals tend to be pretty OK between about 70 degrees F and 80 degrees F or
so, with many corals probably doing best at the upper end of that range or
even a few degrees higher.  Temperatures in the mid 80's are going to be
stressful for many corals.  Temperatures of 90 degrees F are going to be
pretty dangerous for most corals, as I understand things anyway.

And these high temperatures will surely have bigger impacts if the corals
are stressed otherwise, e.g. from low water flow.

I hope this helps.

(To others here with more expertise:  please correct my statements as you
see fit!)

Bill

On Sat, Sep 6, 2014 at 1:33 PM, Dennis Hubbard <dennis.hubbard at oberlin.edu>
wrote:

> Hi Rudy:
>
> Great questions.... with few good answers. We used to talk about ideal
> temperatures related to latitude. However, corals live comfortably in
> the"coral triangle" at temperatures that would bleach Caribbean species.
> Also, we found abundant corals on Easter Island a couple of degrees below
> the lower threshold published for "any corals".... and they bleached at
> temperatures below the "comfortable" range for Caribbean species. I believe
> that this tells us to be very careful when we use terms like "optimal" or
> "suitable". Regarding bleaching, I'd interpret the data to be saying that
> vorals will bleach at some temperature above what they are used to.
> However, this may also prove to be overly simplified - and (others, please
> correct me if I'm wrong here) it could be the zooxanthellae and not the
> corals that are the primary determinants. All this shows how little we
> really "know".
>
> Best,
>
> Dennis
>
>
> On Fri, Sep 5, 2014 at 3:45 PM, Rudy Bonn <rudy_bonn at yahoo.com> wrote:
>
> > Hello coral listers, can someone tell me what the ideal temperature range
> > for growth and reproduction in scleractinian, hermatypic corals.  Does it
> > differ among species, depth range, turbidity, DO, salinity, and any other
> > parameters that should be considered?  Also, what is the thermal range
> for
> > bleaching to likely begin?
> > One earlier post stated that they recorded a temperature of 89 degrees @
> > 30' and that most of the species were showing signs of severe bleaching.
> > Thanks for your consideration, Rudy Bonn.
> >
> >
> > Rudy S Bonn
> > Marine Educator/Biologist
> > Miami, Florida
> > _______________________________________________
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> >
>
>
>
> --
> Dennis Hubbard
> Chair, Dept of Geology-Oberlin College Oberlin OH 44074
> (440) 775-8346
>
> * "When you get on the wrong train.... every stop is the wrong stop"*
>  Benjamin Stein: "*Ludes, A Ballad of the Drug and the Dream*"
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