A comparison of proxy performance in coral biodiversity monitoring

Abstract

The productivity and health of coral reef hab- itat is diminishing worldwide; however, the effect that habitat declines have on coral reef biodiversity is not known. Logistical and financial constraints mean that sur- veys of hard coral communities rarely collect data at the species level; hence it is important to know if there are proxy metrics that can reliably predict biodiversity. Here, the performances of six proxy metrics are compared using regression analyses on survey data from a location in the northern Great Barrier Reef. Results suggest generic rich- ness is a strong explanatory variable for spatial patterns in species richness (explaining 82 % of the variation when measured on a belt transect). The most commonly used metric of reef health, percentage live coral cover, is not positively or linearly related to hard coral species richness. This result raises doubt as to whether management actions based on such reefscape information will be effective for the conservation of coral biodiversity.