Jeremy Carlot*, Héloïse Rouzé, Diego R. Barneche, Alexandre Mercière, Benoit Espiau, Ulisse Cardini, Simon J. Brandl, Jordan M. Casey, Gonzalo Peres-Rosales, Mehdi Adjeroud, Laetitia Hédouin and Valeriano Parravicini
ABSTRACT
Coral reefs provide a range of important services to humanity, which are underpinned by community-level ecological processes such as coral calcification. Estimating these processes relies on our knowledge of individual physiological rates and species- specific abundances in the field. For colonial animals such as reef-building corals, abundance is frequently expressed as the relative surface cover of coral colonies, a metric that does not account for demographic parameters such as coral size. This may be problematic because many physiological rates are directly related to organism size, and failure to account for linear scaling patterns may skew estimates of ecosystem functioning. In the present study, we characterize the scaling of three physiological rates — calcification, respiration, and photosynthesis — considering the colony size for six prominent, reef-building coral taxa in Mo'orea, French Polynesia. After a seven-day acclimation period in the laboratory, we quantified coral physiological rates for three hours during daylight (i.e., calcification and gross photosynthesis) and one hour during night light conditions (i.e., dark respiration). Our results indicate that area-specific calcification rates are higher for smaller colonies across all taxa. However, photosynthesis and respiration rates remain constant over the colony-size gradient. Furthermore, we revealed a correlation between the demographic dynamics of coral genera and the ratio between net primary production and calcification rates. Therefore, intraspecific scaling of reef-building coral physiology not only improves our understanding of community-level coral reef functioning but it may also explain species-specific responses to disturbances.
KEYWORDS
calcification, coral physiology, coral reefs, demographic dynamics, photosynthesis, respiration
AUTHOR CONTRIBUTION
JC: Data curation; Formal analysis Investigation; Validation; Visualization; Writing – original draft; Writing – review & editing
HR: Supervision; Validation; Writing – review & editing
DRB: Conceptualization; analysis; Validation; Writing – review & editing
AM: Data curation; Investigation; Methodology; Writing – review & editing
BE: Data curation; Investigation; Methodology; Writing – review & editing
UC: Data curation; Investigation; Methodology; Writing – review & editing
SJB: Resources; Writing – review & editing
JMC: Writing – review & editing
GPR: Writing – review & editing
MA: Writing – review & editing
LH: Funding acquisition; Writing – review & editing
VP: Conceptualization; Funding acquisition; Resources; Supervision; Validation; Writing – review & editing
The data could be find in the data folder. The script used for the manuscript figures could be find in the R_Scripts folder as Coral_Physiology.R. The second script is about the supplementary analysis.