The inshore coral reef habitats of Palau resemble temperature and pH conditions similar to those projected by 2100 AD. We compared the trophic dynamics and niche width of eight species of Scleractinia found in both inshore and offshore reefs. Stable isotopes (δ13C and δ15N) were used to deduce the relative importance of photosynthesis and heterotrophy to corals living in each habitat. Coral from inshore habitats were found to associate with Symbiodinium trenchii (type D1a). Isotopic values of the animal's tissue, symbiotic algae, and skeleton revealed that these corals relied on zooplankton and particulate organic matter (POM) for metabolism considerably more than conspecifics from offshore reefs. Offshore corals depended more on autotrophy and harbored different species of symbiont. As expected, thermal experiments revealed offshore corals were more negatively impacted by increased temperature. However, comparisons of nutrient allocation under normal and stressful conditions indicated little, or no, significant trade-offs in the physiological performance of some stress-tolerant host-symbiont pairings, contrary to prevailing assumptions. These findings indicate that while inshore corals rely more on a combination of energy sources to acclimatize to stressful environments, their symbioses are maintained with minimal cost to animal growth. Our findings show how coral metabolism may need to shift to cope with increased ocean warming.


Kemp, D. W., University of Georgia, USA, dustinwkemp@gmail.com

Allgeier, J., University of Washington, USA

Hoadley, K. D., University of Delaware, USA

Lewis, A., Penn State University, USA

Wham, F., Penn State University, USA

Warner, M. E., University of Delaware, USA

LaJeunesse, T. C., Penn State University, USA


Oral presentation

Session #:05
Date: 06/23/2016
Time: 14:00
Location: 313 B

Presentation is given by student: No