Geoscience Reference
In-Depth Information
Coral calcii cation decreased by 0.1 mg CaCO
3
g
-
1
day
-
1
per 0.1 unit decrease
in pH. The rate of calcii cation was most strongly correlated with pH, [CO
3
2
-
],
and Ω
a
. A hyperbolic relationship was observed between calcii cation and
[CO
3
2
-
] (and Ω
a
) suggesting a Michaelis-Menten dependence of calcii cation
on [CO
3
2
-
]. Photosynthesis was not affected by changes in pH and p CO
2
alone,
but signii cantly increased owing to a 2 mM bicarbonate addition.
Stylophora pistillata
p CO
2
: 293-2367
Bicarbonate
8 days
[51]
pH
SWS
: 7.56-8.19
Ω
a
: 1.54-9.39
Stylophora pistillata
p CO
2
: 450-470; 734-798
Temperature
5 weeks
Net photosynthesis and respiration normalized per unit protein decreased and
remained unchanged, respectively, in response to elevated p CO
2
.
Photosynthesis increased owing to a warming of 3ºC. Calcii cation decreased
by 50% under high CO
2
combined with high-T treatment, but was not
affected by CO
2
under ambient temperature.
[63]
pH
SWS
: 8.02-8.04; 7.83-7.86
Ca
2+
Stylophora pistillata
Ω
a
: 0.98; 1.95; 2.93;
3.90; 5.85
20 days
Nonlinear decrease in calcii cation rate as a function of decreasing aragonite
saturation state. Saturation state was altered by manipulating calcium
concentration.
[21]
Tubinaria reniformis
p CO
2
: 407-416; 857-882
8 days
Statistically signii cant reduction in calcii cation rate by 13% under
high CO
2
.
[50]
pH
SWS
: 8.06; 7.75-7.76
Ω
a
: 4.37-4.43; 2.26-2.33
Temperate and deep-sea corals
Astrangia poculata
C O
2
: 390; 780
Nutrients
6 months
Calcii cation rates of corals exposed to elevated CO
2
were lower than for
corals exposed to ambient conditions. However, no signii cant difference was
observed when high CO
2
was combined with elevated nutrient conditions.
[31]
pH
T
: 8.03; 7.78
Ω
a
: 3.0; 1.8
Cladocora caespitosa
p CO
2
: 381-423; 407-475;
693-713; 733-779
Temperature
1 yr
High- p CO
2
conditions did not have a signii cant effect on calcii cation and
photosynthetic rates, which seemed to be more dependent on temperature.
[66, 67]
pH
T
: 8.06-8.10; 8.01-8.07;
7.87-7.88; 7.84-7.86
Ω
a
:3.04-3.77; 3.17-3.86;
1.96-2.68; 2.10-2.78
Lophelia pertusa
p CO
2
: 352; 386; 568; 827
24 h
Intermediate- and low-pH conditions resulted in a reduction in calcii cation
by 30 and 56%, respectively. Fast-growing, young polyps were affected
more than older, slower-growing polyps (-59% compared with -40%).
Positive net calcii cation was observed at Ω
a
< 1.
[43]
pH
NBS
: 8.1; 8.1; 7.91; 7.76
Ω
a
: 2.25; 1.89; 1.40; 1.02
Madracis pharencis
p H
U
: 8.0-8.3; 7.3-7.6
12 months
Complete dissolution of skeleton at low pH, but polyps maintained basic
life functions skeleton-less. Corals started calcifying and forming colonies
when returned to normal seawater conditions.
[19]
(continued )
