Geoscience Reference
In-Depth Information
Species
CO
2
(g) (ppmv);
CO
2
(μatm); pH; Ω; [CO
3
2-
]
(μmol kg
-1
)
p
Other
variables/
comments
Duration
Observed effect(s)
Ref.
CCA
p CO
2
: 400; 765 (midday)
pH
NBS
: 8.17; 7.91
51 days
Recruitment of CCA decreased by 78% and percentage cover by 92% under
high CO
2
.
[36]
Corallinaceae
p CO
2
: 334; 957; 20812
Volcanic vent
N/A
Coralline algae cover signii cantly decreased from >60% at ambient pH to
0% at the highest CO
2
and lowest pH conditions.
[27]
pH
T
: 8.14; 7.83; 6.57
Ω
a
: 3.91; 2.43; 0.19
Corallina sessilis
C O
2
: 380; 1000
UV radiation
28 days
Synergistic effects of UV radiation and CO
2
decreased growth by 13%,
photosynthesis by 6%, and calcii cation by 3% in the low-CO
2
treatment.
In the high-CO
2
treatment the same parameters decreased by 47%, 20%,
and 8%, respectively. Both UVA and UVB had negative effects on
photosynthesis and calcii cation although the inhibition by UVB was 2.5 times
that caused by UVA.
[20]
pH
NBS
: 8.3-8.4; 7.8-7.9
Net calcii cation rate (wt% day
-1
) increased linearly between Ω
a
0.7 to 2.0
but decreased in the high-Ω
a
treatment.
Halimeda incrassata
C O
2
: 409; 606; 903; 2856
60 days
[64]
Ω
a
: 2.5; 2.0; 1.5; 0.7
Halimeda opuntia
p H
T
: 8.1; 7.5
3 weeks
CaCO
3
crystals were 43% smaller and the number of crystals per unit area was
66% greater in low pH compared with ambient pH.
[65]
Halimeda renshii
p H
U
: 8.3-8.9
2.5 h
Calcii cation increased 1.6-fold in response to an increase in pH
U
from ~8.3 to
~8.9 induced by photosynthesis by seagrass.
[70]
Halimeda tuna
p H
T
: 8.1; 7.5
3 weeks
CaCO
3
crystals were 18% smaller and the number of crystals per unit area was
11% greater in low pH compared to ambient pH.
[65]
Halimeda tuna
p H
NBS
: 6.0-9.0
2 h
In light conditions, photosynthetic rate increased as a function of decreasing
pH while calcii cation showed a variable response with an initial decrease
between pH
NBS
9 to 7, an increase between pH
NBS
7 to 6.5, and a radical
decrease between pH
NBS
6.5 to 6.
[8]
Hydrolithon sp.
p CO
2
: ~395; ~790; ~1-1382
1 h; 5 days
Overall, calcii cation and photosynthesis, respectively, were positively and
inversely correlated to pH. However, changes in pH
U
between 7.6 and 8.6
had no signii cant effect on calcii cation. pH
U
>8.6 signii cantly enhanced
calcii cation, but resulted in decreased photosynthesis. A reduction in pH
U
from 8.1 to 7.8 caused a reduction in calcii cation by 20% and an increase
in photosynthetitic rates by 13% after 5 days' exposure.
[71]
pH
U
: 8.1; 7.8; 7.6-9.8
Ω
a
: 4; 2; 0.8-21
Hydrolithon sp .
p H
U
: 8.3-8.9
2.5 h
Calcii cation increased 5.8-fold in response to an increase in pH
U
from ~8.3
to ~8.9 induced by photosynthesis by seagrass.
[70]
(continued )
