Environmental Drivers of the Coral Reef Accretion-Erosion Balance in Present and Future Ocean Conditions

Nyssa J. Silbiger, Ph.D. Defense, Department of Biology, University of Hawaii at Manoa
Friday, May 1, 2015 - 3:30pm to 4:20pm
BioMed B-103

Worldwide, declines in coral cover and shifts in coral reef community composition have raised concerns about whether reef accretion will continue to exceed reef erosion. Reef maintenance is influenced by global and local anthropogenic factors such as ocean warming, acidification, eutrophication, and overfishing as well as natural environmental variability. Predicting reef response to environmental stress requires an understanding of both natural and anthropogenic environmental drivers of reef accretion and erosion and how these drivers interact at different spatiotemporal scales. My dissertation work utilized local environmental variability to determine the dominant natural environmental drivers of accretion-erosion rates and bioeroder communities across small (10s m) and broad spatial (1000s km) scales. Additionally, I used a controlled mesocosm experiment to provide context for the effects of global anthropogenic drivers (i.e., temperature and ocean acidification) on the coral reef accretion-erosion balance. The results of my dissertation research highlight the significance of spatial scale in understanding reef dynamics and the need to recognize both reef accretion and erosion processes to predict net coral reef response to future environmental change. Further, my results suggest that increases in reef erosion, combined with expected decreases in calcification, could accelerate the shift of coral reefs to an erosion-dominated system in a high CO2 world.