TitleCoral Luminescence Identifies the Pacific Decadal Oscillation as a Primary Driver of River Runoff Variability Impacting the Southern Great Barrier Reef
Publication TypeJournal Article
Year of Publication2014
AuthorsRodriguez-Ramirez A, Grove CA, Zinke J, Pandolfi JM, Zhao J-xin
Paginatione84305, 1-11
Date PublishedJan 8
Type of ArticleArticle
ISBN Number1932-6203
Accession NumberZOOREC:ZOOR15005025294
KeywordsAbiotic factors, Animalia, Cnidaria, Anthozoa, Zoantharia, Scleractinia, Coelenterates, Colour and luminescence, Coral reef habitat / ] [Climate and weather / Pacific decadal, Habitat, Invertebrates, islands / ]., Marine habitat, Marine zones, oscillation / ] [South Pacific / Australia, Queensland, GBR, Keppel, Pacific Ocean, Physical factors, Porites (Scleractinia)., Porites [Luminescence / Luminescence variability / ] [Reef habitat /
AbstractThe Pacific Decadal Oscillation (PDO) is a large-scale climatic phenomenon modulating ocean-atmosphere variability on decadal time scales. While precipitation and river flow variability in the Great Barrier Reef (GBR) catchments are sensitive to PDO phases, the extent to which the PDO influences coral reefs is poorly understood. Here, six Porites coral cores were used to produce a composite record of coral luminescence variability (runoff proxy) and identify drivers of terrestrial influence on the Keppel reefs, southern GBR. We found that coral skeletal luminescence effectively captured seasonal, inter-annual and decadal variability of river discharge and rainfall from the Fitzroy River catchment. Most importantly, although the influence of El Nino-Southern Oscillation (ENSO) events was evident in the luminescence records, the variability in the coral luminescence composite record was significantly explained by the PDO. Negative luminescence anomalies (reduced runoff) were associated with El Nino years during positive PDO phases while positive luminescence anomalies (increased runoff) coincided with strong/moderate La Nino years during negative PDO phases. This study provides clear evidence that not only ENSO but also the PDO have significantly affected runoff regimes at the Keppel reefs for at least a century, and suggests that upcoming hydrological disturbances and ecological responses in the southern GBR region will be mediated by the future evolution of these sources of climate variability.