|Declining coral calcification on the Great Barrier Reef|
|De'ath, G.; Lough, J.M.; Fabricius, K.E. (2009). Declining coral calcification on the Great Barrier Reef. Science (Wash.) 323(5910): 116-119|
|In: Science (Washington). American Association for the Advancement of Science: Washington DC. ISSN 0036-8075, more|
Calcification; Coral reefs; ISEW, Great Barrier Reef [gazetteer]; Marine
Reef-building corals are under increasing physiological stress from a changing climate and ocean absorption of increasing atmospheric carbon dioxide. We investigated 328 colonies of massive Porites corals from 69 reefs of the Great Barrier Reef (GBR) in Australia. Their skeletal records show that throughout the GBR, calcification has declined by 14.2% since 1990, predominantly because extension (linear growth) has declined by 13.3%. The data suggest that such a severe and sudden decline in calcification is unprecedented in at least the past 400 years. Calcification increases linearly with increasing large-scale sea surface temperature but responds nonlinearly to annual temperature anomalies. The causes of the decline remain unknown; however, this study suggests that increasing temperature stress and a declining saturation state of seawater aragonite may be diminishing the ability of GBR corals to deposit calcium carbonate.