Kenyon, J. C., Dunlap, M. J., Wilkinson, C. B., Page, K. N., Vroom, P. S., Aeby, G. S.

Community structure of hermatypic corals at Pearl and Hermes Atoll, Northwestern Hawaiian Islands: Unique Conservation Challenges in the Hawaiian Archipelago

2007

Atoll Research Bulletin

549

1-23

"The distribution and abundance of scleractinian corals at Pearl and Hermes Atoll (PHA), Northwestern Hawaiian Islands, were determined by georeferenced towed-diver surveys that covered more than 85,000 m2 of benthic habitat and site-specific surveys at 34 sites during 2000 - 2002. Three complementary methods (towed-diver surveys, videotransects, and photoquadrats) were used to quantify percent cover of corals by genus or species in the fore reef, back reef, lagoon, and channel habitats. Three genera -Porites, Montipora, and Pocillopora- account for 97% of the coral cover throughout the atoll, though their relative abundances vary considerably according to habitat and geographic sector within habitats. Fore-reef communities are dominated by massive and encrusting Porites, while the back reef is dominated by Montipora and the lagoon by Porites compressa. All taxa show habitat-specific differences in colony density and size-class distributions as assessed through colony counts within belt transects at fixed sites. These demographic data, which provide the most thorough quantitative description of the coral communities at PHA to date, are used to focus a discussion on risks of reef degradation from salient contemporary hazards, including bleaching, disease, marine debris, and Acanthaster predation. Coral communities at PHA may be the most vulnerable in the Hawaiian Archipelago to bleaching and accumulation of marine debris, thus warranting special management attention. These data also provide a detailed baseline to which population parameters determined from long-term monitoring surveys can be compared to assess the direction, pace, and drivers of change."

Pearl and Hermes, Northwestern Hawaiian Islands