Light spectrum plays a key role in the biology of symbiotic corals, with blue light resulting in higher coral growth, zooxanthellae density, chlorophyll a content and photosynthesis rates as compared to red light. However, it is still unclear whether these physiological processes are blue-enhanced or red-repressed. This study investigated the individual and combined effects of blue and red light on the health, zooxanthellae density, photophysiology and colouration of the scleractinian coral Stylophora pistillata over 6 weeks. Coral fragments were exposed to blue, red, and combined 50/50% blue red light, at two irradiance levels (128 and 256 µmol m-2 s-1). Light spectrum affected the health/survival, zooxanthellae density, and NDVI (a proxy for chlorophyll a content) of S. pistillata. Blue light resulted in highest survival rates, whereas red light resulted in low survival at 256 µmol m-2 s-1. Blue light also resulted in higher zooxanthellae densities compared to red light at 256 µmol m-2 s-1, and a higher NDVI compared to red and combined blue red light. Overall, our results suggest that red light negatively affects the health, survival, symbiont density and NDVI of S. pistillata, with a dominance of red over blue light for NDVI.
- green fluorescent protein
- reef-building corals
- chlorophyll biosynthesis
- zinc toxicity
Wijgerde, T. H. M., Melis, A. A. M., Ferreira Da Silva, C. I., Leal, M. C., Vogels, L., Mutter, C., & Osinga, R. (2014). Red Light Represses the Photophysiology of the Scleractinian Coral Stylophora pistillata. PLoS ONE, 9(3), [e92781]. https://doi.org/10.1371/journal.pone.0092781