Bleaching in reef corals: Physiological and stable isotopic responses
Porter JW, Fitt WK, Spero HJ, Rogers CS, White MW. 1989. Bleaching in reef corals: Physiological and stable isotopic responses. Proceedings of the National Academy of Sciences of the United States of America (PNAS). 86(23):9342-9346
Study of the coral bleaching that affected approximately 40% of corals in the Caribbean during the summer and fall of 1987. Found that energy input from zooxanthellae (the plant organisms that live in coral) was decreased. Bleaching coincided with abnormally high water temperatures. Measured zooxanthellae density, chlorophyll a content, protein weight, lipid weight, carbohydrates weight, dry weight, ratio of photosynthesis to respiration, tissue biomass, carbon and oxygen isotopes in skeletal aragonite. During the late summer to fall of 1987, Caribbean reef corals experienced an intense and widespread discoloration event described as bleaching. Contrary to initial predictions, most bleached corals did not die. However, energy input from zooxanthellae decreased, as estimated from: (i) 13C values, a measure of the discrimination against 13C in 12C/13C assimilation, of skeletal aragonite; (ii) in situ photosynthesis-irradiance measurements; (iii) and tissue biomass parameters of Montastraea annularis and Agaricia lamarcki. The 18O signal, a measure of the discrimination against 18O in 16O/18O assimilation, from M. annularis skeletons demonstrated that this event coincided with abnormally elevated water temperatures.
- Type
- Journal Article
- Authors
- Porter, James; Fitt, William; Spero, Howard; Rogers, Caroline; White, Michael
- Units
- BUIS , VIIS
- Keywords
- Animal Studies, Carbonate skeleton, Caribbean, Coral Bleaching, Coral Reefs, Global Warming, Isotopes, Physiology, stable isotope, Zooxanthellae