Abstract
Experimental studies have shown that coral calcification rates are dependent on light, nutrients, food availability, temperature, and seawater aragonite saturation (Ω<inf>arag</inf>), but the relative importance of each parameter in natural settings remains uncertain. In this study, we applied Calcein fluorescent dyes as time indicators within the skeleton of coral colonies (n = 3) of Porites astreoides and Diploria strigosa at three study sites distributed across the northern Bermuda coral reef platform. We evaluated the correlation between seasonal average growth rates based on coral density and extension rates with average temperature, light, and seawater Ω<inf>arag</inf> in an effort to decipher the relative importance of each parameter. The results show significant seasonal differences among coral calcification rates ranging from summer maximums of 243 ± 58 and 274 ± 57 mmol CaCO<inf>3</inf> m<sup>−2</sup> d<sup>−1</sup> to winter minimums of 135 ± 39 and 101 ± 34 mmol CaCO<inf>3</inf> m<sup>−2</sup> d<sup>−1</sup> for P. astreoides and D. strigosa, respectively. We also placed small coral colonies (n = 10) in transparent chambers and measured the instantaneous rate of calcification under light and dark treatments at the same study sites. The results showed that the skeletal growth of D. strigosa and P. astreoides, whether hourly or seasonal, was highly sensitive to Ω<inf>arag</inf>. We believe this high sensitivity, however, is misleading, due to covariance between light and Ω<inf>arag</inf>, with the former being the strongest driver of calcification variability. For the seasonal data, we assessed the impact that the observed seasonal differences in temperature (4.0 °C), light (5.1 mol photons m<sup>−2</sup> d<sup>−1</sup>), and Ω<inf>arag</inf> (0.16 units) would have on coral growth rates based on established relationships derived from laboratory studies and found that they could account for approximately 44, 52, and 5 %, respectively, of the observed seasonal change of 81 ± 14 mmol CaCO<inf>3</inf> m<sup>−2</sup> d<sup>−1</sup>. Using short-term light and dark incubations, we show how the covariance of light and Ω<inf>arag</inf> can lead to the false conclusion that calcification is more sensitive to Ω<inf>arag</inf> than it really is.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 979-997 |
| Number of pages | 19 |
| Journal | Coral Reefs |
| Volume | 33 |
| Issue number | 4 |
| DOIs | |
| State | Published - 2014 |
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Keywords
- Aragonite saturation state
- Bermuda
- Coral calcification
- Ocean acidification
ASJC Scopus subject areas
- Aquatic Science
Cite this
Multiple driving factors explain spatial and temporal variability in coral calcification rates on the Bermuda platform. / Venti, A.; Andersson, A.; Langdon, Chris.
In: Coral Reefs, Vol. 33, No. 4, 2014, p. 979-997.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Multiple driving factors explain spatial and temporal variability in coral calcification rates on the Bermuda platform
AU - Venti, A.
AU - Andersson, A.
AU - Langdon, Chris
PY - 2014
Y1 - 2014
N2 - Experimental studies have shown that coral calcification rates are dependent on light, nutrients, food availability, temperature, and seawater aragonite saturation (Ωarag), but the relative importance of each parameter in natural settings remains uncertain. In this study, we applied Calcein fluorescent dyes as time indicators within the skeleton of coral colonies (n = 3) of Porites astreoides and Diploria strigosa at three study sites distributed across the northern Bermuda coral reef platform. We evaluated the correlation between seasonal average growth rates based on coral density and extension rates with average temperature, light, and seawater Ωarag in an effort to decipher the relative importance of each parameter. The results show significant seasonal differences among coral calcification rates ranging from summer maximums of 243 ± 58 and 274 ± 57 mmol CaCO3 m−2 d−1 to winter minimums of 135 ± 39 and 101 ± 34 mmol CaCO3 m−2 d−1 for P. astreoides and D. strigosa, respectively. We also placed small coral colonies (n = 10) in transparent chambers and measured the instantaneous rate of calcification under light and dark treatments at the same study sites. The results showed that the skeletal growth of D. strigosa and P. astreoides, whether hourly or seasonal, was highly sensitive to Ωarag. We believe this high sensitivity, however, is misleading, due to covariance between light and Ωarag, with the former being the strongest driver of calcification variability. For the seasonal data, we assessed the impact that the observed seasonal differences in temperature (4.0 °C), light (5.1 mol photons m−2 d−1), and Ωarag (0.16 units) would have on coral growth rates based on established relationships derived from laboratory studies and found that they could account for approximately 44, 52, and 5 %, respectively, of the observed seasonal change of 81 ± 14 mmol CaCO3 m−2 d−1. Using short-term light and dark incubations, we show how the covariance of light and Ωarag can lead to the false conclusion that calcification is more sensitive to Ωarag than it really is.
AB - Experimental studies have shown that coral calcification rates are dependent on light, nutrients, food availability, temperature, and seawater aragonite saturation (Ωarag), but the relative importance of each parameter in natural settings remains uncertain. In this study, we applied Calcein fluorescent dyes as time indicators within the skeleton of coral colonies (n = 3) of Porites astreoides and Diploria strigosa at three study sites distributed across the northern Bermuda coral reef platform. We evaluated the correlation between seasonal average growth rates based on coral density and extension rates with average temperature, light, and seawater Ωarag in an effort to decipher the relative importance of each parameter. The results show significant seasonal differences among coral calcification rates ranging from summer maximums of 243 ± 58 and 274 ± 57 mmol CaCO3 m−2 d−1 to winter minimums of 135 ± 39 and 101 ± 34 mmol CaCO3 m−2 d−1 for P. astreoides and D. strigosa, respectively. We also placed small coral colonies (n = 10) in transparent chambers and measured the instantaneous rate of calcification under light and dark treatments at the same study sites. The results showed that the skeletal growth of D. strigosa and P. astreoides, whether hourly or seasonal, was highly sensitive to Ωarag. We believe this high sensitivity, however, is misleading, due to covariance between light and Ωarag, with the former being the strongest driver of calcification variability. For the seasonal data, we assessed the impact that the observed seasonal differences in temperature (4.0 °C), light (5.1 mol photons m−2 d−1), and Ωarag (0.16 units) would have on coral growth rates based on established relationships derived from laboratory studies and found that they could account for approximately 44, 52, and 5 %, respectively, of the observed seasonal change of 81 ± 14 mmol CaCO3 m−2 d−1. Using short-term light and dark incubations, we show how the covariance of light and Ωarag can lead to the false conclusion that calcification is more sensitive to Ωarag than it really is.
KW - Aragonite saturation state
KW - Bermuda
KW - Coral calcification
KW - Ocean acidification
UR - http://www.scopus.com/inward/record.url?scp=84939883268&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84939883268&partnerID=8YFLogxK
U2 - 10.1007/s00338-014-1191-9
DO - 10.1007/s00338-014-1191-9
M3 - Article
VL - 33
SP - 979
EP - 997
JO - Coral Reefs
JF - Coral Reefs
SN - 0722-4028
IS - 4
ER -