Community Structure of Hermatypic Corals at French Frigate Shoals,Northwestern Hawaiian Islands: Capacity for Resistance and Resilience to Selective Stressors.

Abstract

Georeferenced towed-diver surveys covering more than 100,000 m2 of benthic habitat and site specific surveys at 30 sites during 2000–2002 determined distribution and abundance of scleractinian corals at French Frigate Shoals (FFS), Northwestern Hawaiian Islands. Percentage cover of corals was quantified by genus or species in forereef, backreef, and lagoon habitats and at La Perouse Pinnacles using three complementary methods: towed-diver surveys, video transects, and photoquadrats. Habitat-specific colony density and size-class distributions from measurements made within belt transects at fixed sites indicated that three coral genera, Porites, Pocillopora, and Acropora, accounted for more than 93% of total coral cover throughout the atoll, and their relative percentage cover, densities, and size distributions varied according to habitat and geographic location within the atoll. These descriptive data, which provide the most comprehensive overview yet of the scleractinian coral community at FFS, were used to assess the coral reefs’ potential for resistance and resilience to selective stressors including bleaching, disease, and Acanthaster outbreaks. They also serve as a baseline for an ecosystem-based, long-term monitoring program with an objective of linking coral community change to other biological and physical factors.