Extraordinarily high coral cover on a nearshore, high-latitude reef in south-west Australia

Abstract

Photographic line transects were used to quantify the benthic community at Hall Bank, a small, nearshore, high-latitude reef in south-west Australia. In some places, coral cover was 72.5% (mean = 52.6 ± 0.45%), which is the highest ever recorded coral cover for any reef at or beyond 32˚S. There were no macro-algae, possibly due to a high density of herbivorous sea-urchins (mean = 5.0 ± 0.8 m-2), which we hypothesize may also facilitate the high coral cover observed. Fourteen species of scleractinian corals dominated the benthos, seven of which were from the family Faviidae. Given that Hall Bank is at the limit of environmental tolerance for reef formation, it represents a valuable research opportunity for understanding the factors that build and maintain coral reef biodiversity and resilience.