Dataset: Seawater chemistry data used to calculate rates of organism photosynthesis (P) and calcification (G).

Organism level incubations. Data generated from an experimental coral reef community from Mo’orea, French Polynesia. Results are published in:

Lantz CA, Carpenter RC, Comeau S, Edmunds PJ. Organisms Composing an Experimental Coral Reef Community from Mo'orea, French Polynesia, Exhibit Taxon-Specific Net Production: Net Calcification Ratios. Frontiers in Marine Science. 2017; 4( 298). doi: http://doi.org/10.3389/fmars.2017.00298

Please see publication for complete methodology. 

Seawater samples were taken from each community and chamber at the beginning and end of each 3-h incubation (09:00 -12:00 hrs) and analyzed for temperature, salinity, total alkalinity (TA), and pH. Temperature was measured using a ThermoFisher Scientific Traceable Thermometer (± 0.01 oC) and salinity was measured using a conductivity meter (YSI 3100). Measurements of TA were made within 24 h of collection of seawater samples using open-cell potentiometric titrations (Dickson et al., 2007) on a Mettler Toledo T-50 titrator fitted with a DG115 pH electrode, and analyses were completed in duplicate using 50 mL seawater samples. Measurements of pH were performed using a spectrophotometric procedure with m-cresol dye, and calculated on the Total Scale (pHT).

Values for dissolved inorganic carbon (DIC) were calculated from the measured TA, pHT, salinity, and temperature using the R package seacarb (Lavigne and Gattuso, 2013). Net production (P, mmol C m-2 h-1) and net calcification (G, mmol CaCO3 m-2 h-1), were calculated from changes in DIC (ΔDIC) and TA (ΔTA) using equations from Gattuso et al. (1996).  The ratio of P/G (mmol C mmol CaCO3-1), for both the community and each individual community member, was calculated by dividing each day’s measured P by the contemporaneously measured G (P/Gratio). The slope of P regressed on G (mmol C mmol CaCO3-1), for both the community and each individual community member, was calculated from a best fit type II sum of squares residual model, in which all measures of P over the course of the study were regressed on G for the respective community (P/Gslope), or individual community members. Statistical analyses were performed with SPSS software (SPSS Inc. Version 22.0) running in a Windows environment, and the assumptions of normality and equality of variance were evaluated with graphical analyses of the residuals