Dataset: Shaw 2016: Acropora pulchra calcification experiment 2

A single branch of A. pulchra was sampled from each of the 68 colonies located at 1 m depth and scattered haphazardly along 22 km of Moorea back reef along both the northern and western shores. Samples were collected on November 17, 2015, and were prepared as nubbins as described above for Experiment 1 (see experiment 1 dataset, and Shaw et al. 2016).  The experiment ran for 42 days and was split into two 21-d periods from October - November 2015. During the first 21 days, nubbins were kept under constant pCO2 and temperature conditions that approximated ambient conditions for the back reef of Moorea. For the second 21 days, nubbins were exposed to high temperature (29.4 +- 0.2 C) and elevated pCO2 (1064 +- 13 uatm), to compare Gn under both ambient and high treatments for the same nubbins.

Buoyant weights of the corals were recorded at the beginning of the incubation, after 21 days in ambient treatment, and after 21 days in the high CO2 treatment. The difference between the initial and final buoyant weight was converted to dry skeletal weight over each 21-day period using the aragonite density of 2.93 g cm-3, in accordance with the mineral form of CaCO3 deposited by A. pulchra. Rates of net calcification (Gn) were normalized to the area of organisms estimated using wax dipping (Stimson and Kinzie 1991).​