Detecting and Monitoring Coral Bleaching Events

Abstract

Detecting and monitoring coral bleaching is considered across three broad spatial scales: remote sensing; field studies; and individual coral colonies and polyps. Remote sensing observations have limitations, although aerial photography offers sufficient resolution for detecting and quantifying bleaching. Much lower resolution SST anomalies have also proved valuable as short-term predictors of bleaching and in post hoc bleaching likelihood indicators for un-surveyed areas. Field based observations offer reliability at the expense of reduced spatial coverage. Nested sampling may allow for generalised observations across all reef zones, while allowing for more accurate quantification at fixed locations. Methods should be devised to facilitate comparison with other monitoring; and must include measures of mortality, recovery and recruitment over time. At the scale of individual colonies a broad array of techniques are available for in situ and field laboratory observations, strengthening our understanding of underlying mechanisms and supporting better predictive modelling of future impacts.