In this project, investigators will take advantage of a large-scale, natural disturbance at the NSF-sponsored Moorea Coral Reef LTER site in French Polynesia to explore resilience characteristics of coral reef ecosystems to sets of pulse-press disturbance combinations that alter different attributes of the reef ecosystem. Resilience is the capacity of an ecosystem to return to its previous state following a pulse disturbance such as a cyclone or temperature excursion. Understanding what influences resilience is becoming ever more critical in light of forecasted alterations in disturbance regimes (pulse events) and environmental drivers (press events) associated with global climate change. Global environmental change not only is altering the intensity of press events, it also is changing the frequency and strength of pulse disturbances. Given these complexities, the ability to forecast how ecosystems will respond to or recover from projected changes in pulse and press events is an important scientific challenge.
An unanticipated natural disturbance that is now occurring at the Moorea Coral Reef LTER site provides a propitious opportunity to resolve several key questions regarding resilience, including the trajectory of the system following disturbances that affect different components of the ecosystem, and the existence and strength of positive feedbacks that might produce alternate persistent states. The source of the disturbance is an outbreak of crown-of-thorns seastars (Acanthaster planci) on the reefs surrounding Moorea that has reduced the cover of living coral from ~60% to ~5% cover over large areas. The widespread elimination of just living coral tissue (with coral skeletal structure left intact) provides us the opportunity to manipulate additional features to mimic qualitatively different types of disturbances, and to cross these treatments with various combinations of other environmental stressors. The investigators will conduct surveys and carry out a large field experiment to explore how and why resilience is affected by structural heterogeneity, grazing, corallivory and composition of the microbial community.
The broader impacts of the project will be far reaching because the scientific community and the public have tremendous interest in and concern about conservation of coral reef ecosystems. Results will greatly increase understanding of these systems, and as such, will inform government officials, resource managers and others charged with conservation and management of coral reefs. Scientific findings and technical information from the project will be broadly disseminated through the MCR LTER website (mcr.lternet.edu), scientific publications and presentations, and in the media. Data will be managed by the MCR LTER and made available on the MCR website in accordance with the data policy standards of the LTER Network. Information derived from this research will be included in MCR LTER outreach activities that involve K-12 programs in Southern California as well as community and school outreach in French Polynesia. Undergraduate and graduate students, including those from underrepresented groups, will be involved in research, team research experiences, and development of skills needed to carry out interdisciplinary, collaborative research. The project also will engage in post-doctoral training, and will build international linkages between US scientists and those in South Pacific island nations.
