DOI: 10.5061/dryad.5vg70
title: Data from: Elevated pCO2 affects tissue biomass composition, but not calcification, in a reef coral under two light regimes

description: Ocean acidification (OA) is predicted to reduce reef coral calcification
 rates and threaten the long-term growth of coral reefs under climate
 change. Reduced coral growth at elevated pCO2 may be buffered by
 sufficiently high irradiances; however, the interactive effects of OA and
 irradiance on other fundamental aspects of coral physiology, such as the
 composition and energetics of coral biomass, remain largely unexplored.
 This study tested the effects of two light treatments (7.5 versus
 15.7 mol photons m−2 d−1) at ambient or elevated pCO2 (435 versus
 957 µatm) on calcification, photopigment and symbiont densities, biomass
 reserves (lipids, carbohydrates, proteins), and biomass energy content
 (kJ) of the reef coral Pocillopora acuta from Kāne‘ohe Bay, Hawai‘i. While
 pCO2 and light had no effect on either area- or biomass-normalized
 calcification, tissue lipids gdw−1 and kJ gdw−1 were reduced 15% and 14%
 at high pCO2, and carbohydrate content increased 15% under high light. The
 combination of high light and high pCO2 reduced protein biomass (per unit
 area) by approximately 20%. Thus, under ecologically relevant irradiances,
 P. acuta in Kāne‘ohe Bay does not exhibit OA-driven reductions in
 calcification reported for other corals; however, reductions in tissue
 lipids, energy content and protein biomass suggest OA induced an energetic
 deficit and compensatory catabolism of tissue biomass. The null effects of
 OA on calcification at two irradiances support a growing body of work
 concluding some reef corals may be able to employ compensatory
 physiological mechanisms that maintain present-day levels of calcification
 under OA. However, negative effects of OA on P. acuta biomass composition
 and energy content may impact the long-term performance and scope for
 growth of this species in a high pCO2 world.
description: R markdown .Rmd
 fileThis is an R markdown
 .Rmd file. This file is opened in RStudio and has all script and code that
 generates the html R markdown output.Wall et al. OA_light coral
 biomass.RmdR markdown graphing and
 analyzing OA and light effectsThis R markdown has the
 code used to analyze seawater chemistry, generate normalized response
 variables, perform principal component analyses, run mixed effect models,
 and generate figures.Wall_et_al._OA_light_coral_biomass.htmlWall et al. OA-Light response variablesThis dataframe has all response variable measured in the experiment. Normalizing the responses to skeletal area or tissue biomass is performed in accompanying R-markdown.Wall et al_OAxLight_R.csvMetadata_Wall et al_OAxLight_R.docxWall et al. OA-Light seawater chemistryDataframe shows seawater chemistry for experimental pCO2 manipulations. See R markdown for more analyses.Seacarb_ALL TANKS.csvMetadata_SWchem_Treatments_OAxLight.docxWall et al. OA-Light seawater temperature and salinityThis data file contains a log of seawater temperature and salinity for treatment tanks over the course of the experiment.Exp_temp salinity_OAxLight.csvMetadata_Exp_temp salinity_OAxLight.docx