Dataset: algae_calcification
Deployment: lab_Carpenter_Moorea

For the carbonate chemistry:

Seawater pH was measured twice a day (08:00 hrs and 18:00 hrs) in each incubation tank, using a pH meter (Orion, 3-stars mobile) calibrated every 2-3 d on the total scale using Tris/HCl buffers (Dickson, San Diego, USA) with a salinity of 34.5. Total alkalinity of the seawater in the tanks was measured every 2 d, using single samples drawn from each tank in glass-stoppered bottles (250 mL). Samples were analyzed for total alkalinity within 1 d using open cell, potentiometric titration and an automatic titrator (T50, Mettler-Toledo). Titrations were conducted on 50-mL samples at ~ 24 °C, and total alkalinity calculated as described by Dickson et al. [2007]. Titrations of certified reference materials (CRM) provided by A. G. Dickson (batch 105) yielded total alkalinity values within 3.8 umol kg-1 of the nominal value (SD = 3.1 umol kg-1; n = 19). Salinity in the experimental tanks was measured every 2 d using a conductivity meter (YSI 3100). Total alkalinity, pH on the total scale (pHT), temperature, and salinity were used to calculate the carbonate chemsitry using the seacarb package (Lavigne and Gattuso 2012) running in R software (R Foundation for Statistical Computing).

Calcification:

Buoyant weight (± 1 mg) was recorded before and after the 15 d of incubation (following 15 d of acclimation), and the difference between the two was converted to dry weight using an aragonite density of 2.93 g cm^-3 for Halimeda, and a calcite density of 2.71 g cm^-3 for coralline algae. Calcification was normalized by biomass for algae.