Porites' coral calcifying fluid chemistry regulation under normal- and low-pH seawater conditions in Palau Archipelago: Impacts on growth properties
Canesi, M.; Douville, E.; Bordier, L.; Dapoigny, A.; Coulibaly, G.E.; Montagna, P.; Beraud, E.; Allemand, D.; Planes, S.; Furla, P.; Gilson, E.; Roberty, S.; Zoccola, D.; Reynaud, S. (2024). Porites' coral calcifying fluid chemistry regulation under normal- and low-pH seawater conditions in Palau Archipelago: Impacts on growth properties. Sci. Total Environ. 911: 168552. https://dx.doi.org/10.1016/j.scitotenv.2023.168552 In: Science of the Total Environment. Elsevier: Amsterdam. ISSN 0048-9697; e-ISSN 1879-1026, more |  |
| Keywords | Porites Link, 1807 [WoRMS]
Marine/Coastal | | Author keywords | Ocean acidification; Massive Porites corals; Skeletal density; Calcifying fluid; Palau; Biological carbonate chemistry regulation |
| Authors | | Top | - Canesi, M.
- Douville, E.
- Bordier, L.
- Dapoigny, A.
- Coulibaly, G.E.
| - Montagna, P.
- Beraud, E.
- Allemand, D.
- Planes, S.
- Furla, P.
| - Gilson, E.
- Roberty, S., more
- Zoccola, D.
- Reynaud, S.
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| Abstract | Ongoing ocean acidification is known to be a major threat to tropical coral reefs. To date, only few studies have evaluated the impacts of natural long-term exposure to low-pH seawater on the chemical regulation and growth of reef-building corals. This work investigated the different responses of the massive Porites coral living at normal (pHsw ~ 8.03) and naturally low-pH (pHsw ~ 7.85) seawater conditions at Palau over the last decades. Our results show that both Porites colonies maintained similar carbonate properties (pHcf, [CO32−]cf, DICcf, and Ωcf) within their calcifying fluid since 1972. However, the Porites skeleton of the more acidified conditions revealed a significantly lower density (~ 1.21 ± 0.09 g·cm−3) than the skeleton from the open-ocean site (~ 1.41 ± 0.07 g·cm−3). Overall, both Porites colonies exerted a strong biological control to maintain stable calcifying fluid carbonate chemistry that favored the calcification process, especially under low-pH conditions. However, the decline in skeletal density observed at low pH provides critical insights into Porites vulnerability to future global change.
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