[Coral-List] Temperature and elevated pCO2

[Dr. Stephen Jameson]

Dear Jean-Pierre,

Thanks for the ocean acidification note regarding:

> The following papers address the interaction between temperature and
> elevated pCO2:
> 
> Kleypas J. A., Buddemeier R. W., Eakin C. M., Gattuso J.-P., Guinotte
> J., Hoegh-Guldberg O., Iglesias-Prieto R., Jokiel P. L., Langdon C.,
> Skirving O. W. & Strong A. E., 2005. Comment on ³Coral reef
> calcification and climate change: The effect of ocean warming².
> Geophysical Research Letters L08601. doi:10.1029/2004GL022329.
> 
> Reynaud S., Leclercq N., Romaine-Lioud S., Ferrier-Pagès C., Jaubert J.
> & Gattuso J.-P., 2003. Interacting effects of CO2 partial pressure and
> temperature on photosynthesis and calcification in a scleractinian
> coral. Global Change Biology 9(11):1660-1668.
> 
> Cheers,
> jp

JP, In your reference list I'm surprised you didn't include McNeil's
counter-response:

McNeil, B. I., R. J. Matear, and D. J. Barnes (2005),
Reply to comment by Kleypas et al. on ŒŒCoral reef calcification
and climate change: The effect of ocean warming,¹¹ Geophys. Res.
Lett., 32, L08602, doi:10.1029/2005GL022604.

to your first reference:

> Kleypas J. A., Buddemeier R. W., Eakin C. M., Gattuso J.-P., Guinotte
> J., Hoegh-Guldberg O., Iglesias-Prieto R., Jokiel P. L., Langdon C.,
> Skirving O. W. & Strong A. E., 2005. Comment on ³Coral reef
> calcification and climate change: The effect of ocean warming².
> Geophysical Research Letters L08601. doi:10.1029/2004GL022329.

I've attached McNeil's response below for the benefit of the Coral-List
readers, who like myself have limited time and are trying to make sense out
of ocean acidification research results and recent newspaper/magazine
articles that do not put the ocean acidification problem in perspective with
respect to increasing sea surface temperature.

So back to my original request,

>Joan 

> Your thoughts/guidance would be appreciated, so we can all respond to these
> calcification challenge questions accurately.


Best regards,

Dr. Stephen C. Jameson, President
Coral Seas Inc. - Integrated Coastal Zone Management
4254 Hungry Run Road, The Plains, VA  20198-1715  USA
Office:  703-754-8690, Fax:  703-754-9139
Email:  sjameson at coralseas.com
Web Site:  http://www.coralseas.com

and

Research Collaborator
Smithsonian National Museum of Natural History
Washington, DC 20560


*******

Reply to comment by Kleypas et al. on ŒŒCoral reef calcification and
climate change: The effect of ocean warming¹¹

Ben I. McNeil,1 Richard J. Matear,2 and David J. Barnes3
Received 2 February 2005; revised 1 March 2005; accepted 8 March 2005;
published 20 April 2005.

1Centre for Environmental Modelling and Prediction, University of
New South Wales, Sydney, New South Wales, Australia.
2CSIRO Marine Research, Hobart, Tasmania, Australia.
3Australian Institute of Marine Science, Townsville, Queensland,
Australia.


Citation: McNeil, B. I., R. J. Matear, and D. J. Barnes (2005),
Reply to comment by Kleypas et al. on ŒŒCoral reef calcification
and climate change: The effect of ocean warming,¹¹ Geophys. Res.
Lett., 32, L08602, doi:10.1029/2005GL022604.


1. Introduction

[1] In their original paper [Kleypas et al., 1999] and in
subsequent papers, Kleypas and others considered how
acidification of the surface ocean by rising atmospheric
CO2 might impact coral reef calcification by affecting the
aragonite saturation state of seawater (arag). They
concluded that coral calcification is already compromised
and predicted further declines through the 21st Century. We
took this a step further [McNeil et al., 2004] (herein referred
to as MMB04) by using a coupled atmosphere-ocean model
that takes into account future changes in arag due to rising
sea surface temperature (SST), changes in ocean circulation
and changes in oceanic biological activity. We also took into
account increases in calcification that may be expected due
to rising SST by using in-situ evidence. In their response to
our paper, Kleypas et al. [2005] (herein referred to as K05)
seek to discredit our finding that coral reef calcification may
increase through the 21st Century.

2. Combining the Calcification: SST and Calcification:
arag Relationship

[2] Many of their criticisms relate to our choice of the
calcification-SST relationship provided by Lough and
Barnes [2000] (hereinafter referred to as LB2000) and to
the relationship itself. This relationship was obtained by
correlating the annual average SST with annual average
calcification determined from annual density banding
patterns in the skeletons of 554 colonies of massive Porites
from 44 reefs encompassing a SST range of 23 to 29
C.
The relationship is linear across the temperature range
and accords with other work [Bessat and Buigues, 2001;
Carricart-Ganivet, 2004; Nie et al., 1997].

[3] K05 point out that temperature response curves
obtained experimentally show that calcification rates
increase with temperature but decline once the temperatures
rise above those normally experienced by the experimental
corals. We acknowledge this issue in our paper. K05 choose
to assume that corals will not adapt or acclimatise. As they
point out, it is implicit in our paper that corals will adapt or
acclimatise. Interestingly, a similar problem arose with
regard to coral bleaching. The position initially adopted
was that corals have no defences against factors bringing
about bleaching [e.g., Hoegh-Guldberg, 1999]. It is now
apparent that corals have a variety of mechanisms by which
they can accommodate changes in environmental factors
that bring about bleaching [Baker et al., 2004; Brown et al.,
2002; Little et al., 2004; Rowan, 2004].

[4] McNeil et al. [2004] (hereinafter referred to as
MMB04) assume that the calcification rate of corals is the
sum of two linear responses, a temperature response
(LB2000) and a Warag response [Langdon et al., 2000].
Kleypas et al. [2005] (hereinafter referred to as K05)
suggest that this assumption is not valid based upon
a laboratory study that found the combined effects of
elevated temperature and lowering Warag were not linear
for Stylophora pistillata [Reynaud et al., 2003]. Interestingly
however, Reynaud et al. [2003] also found that calcification
did not decrease with lowering Warag when holding temperature
constant and as such contradicts previous calcification
projections from Kleypas and others based solely on Warag.
As acknowledged in our paper, we suspect that the effects of
both Warag and SST on calcification rate are more complex
and species-dependent than the simple relationships used by
Kleypas et al. [1999] and MMB04. It is hoped that our study
may promote future experiments beyond Reynaud et al.
[2003] that further investigate the calcification response to
elevated CO2 and SST.

[5] We agree that Porites calcification is not equivalent to
reef calcification. Unfortunately, there are no equivalent
data for whole reefs, or for significant areas within reefs.
We took Porites calcification to be indicative of overall reef
calcification since it is the dominant reef-building coral
within the Pacific while Montastrea, which shows a similar
temperature dependency as Porites [Carricart-Ganivet,
2004], is the dominant reef-builder in the Atlantic.

3. Porites Calcification: Temperature Relationship

[6] K05 suggest that the LB2000 relationship did not take
into account light, which co-varies with temperature. Light
was taken into account by LB2000: partial correlations
showed that solar radiation added only 1.5% to the 83%
of variance explained by SST. They also suggest that the
relationship is not applicable above 
27
C because a single
high SST point was obtained from ŒŒa very different
environment¹¹ (the reefs around Phuket Island, Thailand).
In our view, this point is debatable. However, they overlooked
a far more telling point. In our paper, we noted a
personal communication from J. Lough that data for colonies
from the Persian Gulf and New Ireland, Papua New
Guinea followed the LB2000 temperature: calcification
relationship. Average annual SSTs for New Ireland
(29.5
C) exceed those for Phuket Island (28.7
C).

[7] K05 suggest that the Porites temperature: calcification
curve is a response to temperature-related changes in
Warag. We explored the possible contributions that variations
in Warag would make to the LB2000 relationship by using
the recently published global ocean carbon data set [Key et
al., 2004] with standard CO2 dissociation constants. We
calculate Warag to vary between 3.88 to 4.02 within the
temperature range 23­29
C; considerably less than the
estimate by K05. Using the rather high dependency of
calcification upon Warag quoted by Langdon et al. [2000]
as an upper limit [cf. Reynaud et al., 2003], we estimate that
temperature-related changes in Warag could only increase
calcification by 15% in comparison to the observed 340%
increase in Porites calcification rate from LB2000. We also
directly determined in situ Warag in the western Pacific
using measurements of dissolved inorganic carbon (DIC),
alkalinity (ALK) and salinity. For latitudes relevant to
LB2000, the range of in situ Warag is between 3.9 and 4.1
which would vary calcification by 24% - again, compared
with the observed 340% variation [calculations and graphs
can be obtained from B.I.McN].

[8] K05 suggest that a ŒŒspatially derived relationship
should not be applied to temporal predictions¹¹ because
ŒŒchanges from one latitude to another likely involve genetic
differences between locally adapted (over thousands of
years) corals and are thus unrelated to phenotypic changes
that would occur within a single individual¹¹. Figure 7 in
LB2000 does not support this view where this issue
was examined; it shows the temporally derived data from
Lough and Barnes [1997] to fit well with the spatially
derived relationship. Further, Bessat and Buigues [2001]
show a temporal response of Porites calcification to changing
SST similar to the relationship that we used. The
contrast of spatially and temporally-derived SST: calcification
data does not bear close examination. Each of the
points making up the spatially derived relationship of
LB2000 is annual calcification averaged over several years
of growth common to a number of different coral colonies.
Thus, each point is the resultant of calcification over time,
i.e., the resultant of a temporal relationship. It is unlikely
that a linear relationship with average annual SST would
account for 83% of the variation in average annual calcification
if corals at the diverse locations have locally adapted
SST: calcification curves with slopes significantly different
from that of the overall relationship.

4. Definition of Coral Reef Habitat

[9] MMB04 defined the reef habitat as the oceanic area
where SST exceeds 18
C in the control climate simulation.
It is true that a more appropriate definition would have
included water depth. Unfortunately however, coarse resolution
climate models do not sufficiently resolve the shallow
water environment from the open ocean. Having a reef
habitat with an average baseline SST less than the present
day value for the reef environment does not in itself bias our
projections since we only use the climate change simulation
to project the change in SST from our baseline value. Our
definition of reef habitat therefore gives a broad indication
of the likely future changes in calcification rate. We believe
our projections are more realistic than Kleypas et al. [1999],
because we explicitly include climate change induced
changes in SST, DIC, ALK, salinity and Warag, rather than
prescribing a uniform warming of 2
C. Our study does not
include the ŒŒpoleward¹¹ expansion of the reef habitat with
global warming as suggested by K05. It is limited to
changes within the present reef habitat.

5. Other Temperature Effects

[10] We noted in our paper that our predictions did not
take account of ŒŒadverse future effects of coral bleaching¹¹.
K05 suggest that this is unrealistic. We feel we acted
properly by defining the problem addressed by our paper­
projected changes in coral reef calcification rate with global
warming ­ and by acknowledging coral bleaching may
significantly alter our predictions. There is a sharp contrast
between the paucity of recent experimental work relating
coral calcification to climate change and the considerable
recent work linking other aspects of coral metabolism,
especially coral bleaching, to climate change.

6. Conclusion

[11] There can be no doubt that the response of corals,
coral reefs and other significant reef organisms to climate
variability will be complex. MMB04 took into account
factors not previously included in equivalent analyses and
obtained a result different from those previously reported.
We are aware of uncertainties in our findings. Even so, we
feel they provide a useful addition to our understanding of
the issue. In our view, they would be useful even if they
served only to highlight those uncertainties. To us, the
fundamental research question that remains to be answered
is, ŒŒCan organisms and ecosystems accommodate, acclimatise
to or adapt to rising temperatures faster than ocean
temperatures may rise?¹¹

References

Baker, A. C., C. J. Starger, T. R. McClanahan, and P. W. Glynn (2004),
Corals¹ adaptive response to climate change, Nature, 430, 741­ 742.

Bessat, F., and D. Buigues (2001), Two centuries of variation in coral
growth in a massive Porites colony from Moorea (French Polynesia),
Palaeogeogr. Palaeoclimatol. Palaeoecol., 175, 381­392.

Brown, B. E., C. A. Downs, R. P. Dunne, and S. W. Gibb (2002), Exploring
the basis of thermotolerance in the reef coral Goniastrea aspera, Mar.
Ecol. Ser., 242, 119­129.

Carricart-Ganivet, J. P. (2004), Sea surface temperature and the growth of
the west Atlantic reef-building coral Montastraea annularis, J. Exp. Mar.
Biol., 302, 249­260.

Hoegh-Guldberg, O. (1999), Climate change, coral bleaching and the future
of the world¹s coral reefs, Mar. Freshw. Res., 50, 839­ 866.

Key, R. M., A. Kozyr, C. L. Sabine, K. Lee, R. Wanninkhof, J. L. Bullister,
R. A. Feely, F. J. Millero, C. Mordy, and T.-H. Peng (2004), A global
ocean carbon climatology: Results from Global Data Analysis Project
(GLODAP), Global Biogeochem. Cycles, 18, GB4031, doi:10.1029/
2004GB002247.

Kleypas, J. A., et al. (1999), Geochemical consequences of increased
atmospheric carbon dioxide on coral reefs, Science, 284, 118­ 120.

Kleypas, J. A., et al. (2005), Comment on ŒŒCoral reef calcification and
climate change: The effect of ocean warming,¹¹ Geophys. Res. Lett., 31,
L08601, doi:10.1029/2004GL022329.

Langdon, C., et al. (2000), Effect of calcium carbonate saturation state on
the calcification rate of an experimental coral reef, Global Biogeochem.
Cycles, 14, 639­ 654.

Little, A. F., M. J. H. van Oppen, and B. L.Willis (2004), Flexibility in
algal endosymbioses shapes growth in reef corals, Science, 304, 1492­ 1494.

Lough, J. M., and D. J. Barnes (1997), Several centuries of variation in
skeletal extension, density and calcification in massive Porites colonies
from the Great Barrier Reef, J. Exp. Mar. Biol., 211, 29­67.

Lough, J. M., and D. J. Barnes (2000), Environmental controls on growth of
the massive coral Porites, J. Exp. Mar. Bio., 245, 225­ 243.

McNeil, B. I., R. J. Matear, and D. J. Barnes (2004), Coral reef
calcification and climate change: The effect of ocean warming, Geophys. Res.
Lett., 31, L22309, doi:10.1029/2004GL021541.

Nie, B., et al. (1997), Relationship between coral growth rate and sea
surface temperature in the northern part of South China Sea, Sci. China, 40,
173­182.

Reynaud, S., et al. (2003), Interacting effects of CO2 partial pressure and
temperature on photosynthesis and calcification in a scleractinian coral,
Global Change Biol., 9, 1660­ 1668.

Rowan, R. (2004), Coral bleaching: Thermal adaptation in reef coral
symbionts, Nature, 430, 742, doi:10.1038/430742.


D. J. Barnes, Australian Institute of Marine Science, PMB 3, Mail Centre,
Townsville, QLD 4810, Australia.
R. J. Matear, CSIRO Marine Research, GPO Box 1538, Hobart, Tas
7001, Australia.
B. I. McNeil, Centre for Environmental Modelling and Prediction,
University of New South Wales, Sydney, NSW 2052, Australia.
(b.mcneil at unsw.edu.au)



Copyright 2005 by the American Geophysical Union.
0094-8276/05/2005GL022604$05.00
L08602 1 of 3

*******

>Hi:
> 
> The following papers address the interaction between temperature and
> elevated pCO2:
> 
> Kleypas J. A., Buddemeier R. W., Eakin C. M., Gattuso J.-P., Guinotte
> J., Hoegh-Guldberg O., Iglesias-Prieto R., Jokiel P. L., Langdon C.,
> Skirving O. W. & Strong A. E., 2005. Comment on ³Coral reef
> calcification and climate change: The effect of ocean warming².
> Geophysical Research Letters L08601. doi:10.1029/2004GL022329.
> 
> Reynaud S., Leclercq N., Romaine-Lioud S., Ferrier-Pagès C., Jaubert J.
> & Gattuso J.-P., 2003. Interacting effects of CO2 partial pressure and
> temperature on photosynthesis and calcification in a scleractinian
> coral. Global Change Biology 9(11):1660-1668.
> 
> Cheers,
> jp
> 
>> Can you clarify for the Coral-List how increasing sea surface temperature
>> affects the calcification challenge in corals with increasing acidification?
> 


> Dear Joan,
> 
> Can you clarify for the Coral-List how increasing sea surface temperature
> affects the calcification challenge in corals with increasing acidification?
> 
> Ben McNeil's research on Porites in Australia shows that calcification
> increases with increasing acidification and increasing sea surface
> temperature.  The research by Marshall and Clode shows a bell-shape
> calcification trajectory (i.e., increasing calcification up to 2-3degC warming
> and then declining  after that).
> 
> Was the relationship of increasing sea surface temperatures and increasing
> acidification on calcification discussed at the workshop?
> 
> It seems like all the recent calcification challenge press releases coming out
> regarding increasing acidification are not put into context with respect to
> increasing sea surface temperature.
> 
> Your thoughts/guidance would be appreciated, so we can all respond to these
> calcification challenge questions accurately.
> 
> Thanks!

> 
> Best regards,
> 
> Dr. Stephen C. Jameson, President
> Coral Seas Inc. - Integrated Coastal Zone Management
> 4254 Hungry Run Road, The Plains, VA  20198-1715  USA
> Office:  703-754-8690, Fax:  703-754-9139
> Email:  sjameson at coralseas.com
> Web Site:  http://www.coralseas.com
> 
> and
> 
> Research Collaborator
> Smithsonian National Museum of Natural History
> Washington, DC 20560
> 
> 
>> Colleagues:
>> 
>> A new report on ocean acidification and marine calcification (with
>> emphasis on coral reefs) is now available in pdf format at
>> http://www.isse.ucar.edu/florida/
>> 
>> The report distills input of some 50 scientists and is probably the most
>> comprehensive report yet on this topic, spelling out the latest in terms
>> of what we know but also what the most pressing questions are.  It is
>> heavily referenced and we will soon be providing the reference list for
>> downloading into reference software.  The report also serves as a "Guide
>> to Future Research," and lists multiple criteria that should be
>> considered when designing research projects.
>> 
>> We hope you find this useful as both a reference and a guide.
>> 
>> [I recommend downloading the condensed version, as it is MUCH smaller
>> and the reduction in figure quality is hardly noticeable.]
>> 
>> All the best,
>> J Kleypas
>