Impact of an experimental eutrophication on the processes of bioerosion on the reef: One Tree Island, Great Barrier Reef, Australia

Abstract

The components of bioerosion were investigated during ENCORE (The Effect of Nutrient Enrichment on Coral Reefs) over 2years of controlled additions of dissolved inorganic nitrogen and phosphorus. The study was carried out at One Tree Island, southern Great Barrier Reef, Australia. Rates of microbioerosion and external erosion by grazing were significantly higher at the enriched sites than at the control sites. Rates of accretion by coralline algae were also significantly higher at enriched sites. In contrast, rates of macroboring were not significantly different between enriched and control sites.This study highlights the importance of improving water quality on the reef to reduce rates of bioerosion given that quantities of dead coral substrates have recently substantially increased as a result of coral bleaching (Hughes et al., 2015) and several Crown of Thorns plagues (Fabricius et al., 2010; De'ath et al., 2012), on the Great Barrier Reef.