Dataset: organism_p_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