EGU21-15029, updated on 04 Mar 2021
https://doi.org/10.5194/egusphere-egu21-15029
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

The coral reef-dwelling Peneroplis spp. shows calcification resilience to ocean acidification conditions - results from culture experiments

Laurie Charrieau1, Katsunori Kimoto1, Delphine Dissard2, Beatrice Below3, Kazuhiko Fujita4, Yukiko Nagai1, and Takashi Toyofuku1
Laurie Charrieau et al.
  • 1JAMSTEC
  • 2IRD/UMR LOCEAN, IRD-CNRS-MNHN-Sorbonne Université
  • 3UMR CR2P, IRD-CNRS-MNHN-Sorbonne Université
  • 4University of the Ryukyus

Ocean acidification is a consequence of current anthropogenic climate changes. The concomitant decrease in pH and carbonate ion concentration in sea water may have severe impacts on calcifying organisms. Coral reefs are among the first ecosystems recognized vulnerable to ocean acidification. Within coral reefs, large benthic foraminifera (LBF) are major calcium carbonate producers.

The aim of this study was to evaluate the effects of varying pH on survival and calcification of the symbiont-bearing LBF species Peneroplis spp. We performed culture experiments to study their resistance to ocean acidification conditions, as well as their resilience once placed back under open ocean pH (7.9).

After three days, small signs of test decalcification were observed on specimens kept at pH 7.4, and severe test decalcification was observed on specimens kept at pH 6.9, with the inner organic lining clearly appearing. After 32 days under pH 7.4, similar strongly decalcified specimens were observed. All the specimens were alive at the end of the experiment. This result demonstrates the resistance of Peneroplis spp. to an acidified pH, at least on a short period of time.

After being partially decalcified, some of the living specimens were placed back at pH 7.9. After one month, the majority of the specimens showed recalcification features, mostly by addition of new chambers. The trace elements concentrations of the newly formed chambers were analysed by LA-ICPMS. Interestingly, more chambers were added when food was given, which highlights the crucial role of energy source in the recalcification process. Moreover, the newly formed chambers were most of the time abnormal, and the general structure of the tests was altered, with potential impacts on reproduction and in situ survival. In conclusion, if symbiont-bearing LBF show some resistance and resilience to lowered pH conditions, they will remain strongly affected by ocean acidification.

How to cite: Charrieau, L., Kimoto, K., Dissard, D., Below, B., Fujita, K., Nagai, Y., and Toyofuku, T.: The coral reef-dwelling Peneroplis spp. shows calcification resilience to ocean acidification conditions - results from culture experiments, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15029, https://doi.org/10.5194/egusphere-egu21-15029, 2021.

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