Page, K. N.

Factors influencing benthic distributional patterns in a near-pristine coral reef ecosystem: Pearl and Hermes Atoll

2006

Manoa, HI

University of Hawaii

Many factors, both biotic and abiotic, act to structure coral reef communities. I examined potential determinants of coral reef community structure in a near-pristine system, Pearl and Hermes Atoll (PHA). I measured percent cover of benthic organisms along with herbivorous fish density and biomass, urchin density, nutrient availability, and wave exposure at PHA.. It was determined that wave exposure and herbivory (fish and urchins) largely explain distributional patterns observed in benthic communities. For instance, when all benthic functional groups were combined in a multivariate analysis, herbivorous fish density combined with wave exposure was identified as having the highest significant correlation with benthic community composition at PHA.. Nutrient availability, based on algal tissue nutrient content, however, did not correlate with percent cover of benthic organisms. My results suggest that wave exposure along with top-down mechanisms have primacy over bottom-up mechanisms in an ecosystem free from direct anthropogenic impacts, including fishing.

FY2003 CRCP Project ID 1221; Project Title: Pacific Reef Assessment and Monitoring Program (Pacific RAMP): Biennial Monitoring for the U.S. Pacific Islands and Atolls; Principal Investigator: Rusty Brainard