Table 1.
Analysis of variance testing the effects of temperature and experimental conditions on chlorophyll content, photosynthesis and respiration of Turbinaria reniformis and Stylophora pistillata.
Figure 1.
Photochemistry parameters measured using the DualPAM. Photosystem 2 (PS2) parameters are measured from chlorophyll fluorescence and PS1 parameters are based on absorbance at 875 compared with 830 nm.
Abbreviated variable names correspond to definitions in boxes and are referred to throughout the paper. Details of measurement are outlined in Methods section “Fluorometry – PS2 fluorescence and PS1 absorbance”.
Figure 2.
Chlorophyll levels for colonies of Turbinaria reniformis and Stylophora pistillata incubated at control (26°C) and high (32°C) temperatures under different light levels and feeding regimes.
Lower case letters denote statistically homogeneous subsets across temperature and experiment but within species, as shown in Table 1, and error bars represent standard error.
Figure 3.
Protein contents for colonies of Turbinaria reniformis and Stylophora pistillata incubated at control (26°C, grey bars) and high (32°C, open bars) temperatures under different light levels and feeding regimes.
Summary statistics are provided in Table 2 and error bars represent standard error.
Table 2.
Analysis of variance testing the effects of temperature and experimental conditions on three photosystem proteins Rubisco (RbcL), PS2 (PsbA) and PS1 (PsaC).
Figure 4.
Component scores from Principal Components Analysis of photophysiology data.
Points show scores for individual coral colonies and indicate experiment, species and temperature dependence of scores on the first three principal components respectively (PC1, PC2 and PC3). Summary statistics are provided in Table 3.
Table 3.
Variable loadings and correlations between variables and components (PC1 – 3) defined through Principal Components Analysis of photochemical parameters.
Figure 5.
Variation in photophysiology parameters identified through principal components analysis as having a strong effect on overall photochemistry.
Data for each variable are pooled and plotted according to the effect identified for the principal component with which they were strongly associated (Fig 4, Table 3). For example, Y(ND) was strongly related to PC2 which differentiated between the study species Turbinaria reniformis (T) and Stylophora pistillata (S). 26 and 32 denote the two different incubation temperatures of 26°C and 32°C. Bars show means and standard errors.
Figure 6.
Rapid light curves showing variation in photophysiology parameters identified through principal components analysis as having a strong effect on overall photochemistry.
Data for each variable are pooled and plotted according to the effect identified for the principal component with which they were strongly associated (Table 3). In A), data are pooled across species and temperatures because Y(NPQ) was strongly related to PC1 which differentiated between experiments. In B) data are pooled across temperatures and experiments and in C) data are pooled across species and experiments. Points show means and error bars depict standard error.
Figure 7.
Electron transport through PS2 versus that through PS1, corrected for relative contents of each photosystem based on protein quantifications.
A, B and C are the results obtained with Turbinaria reniformis under A) low light, fed; B) low light unfed; c) high light unfed conditions. Error bars represent standard error.
Figure 8.
Photosynthesis and respiration for colonies of Turbinaria reniformis and Stylophora pistillata incubated at control (26°C) and high (32°C) temperatures under different light levels and feeding regimes.
Lower case letters denote statistically homogeneous subsets across temperature and experiment but within species, as shown in Table 1. Positive values show rate of photosynthesis at 450 µmol photons m−2 s−1and negative values show rate of respiration in darkness. Error bars represent standard error.
Figure 9.
Relationship between gross photosynthesis and relative electron transport.
In A) relative electron transport through PS2 is shown, and in B) relative electron transport through PS1. Points represent individual colonies, filled circles show values for Turbinaria reniformis and open circles show values for Stylophora pistillata. Lines in A) are trend lines representing significant correlations.