This study provides a quantitative approach that predicts the response of coral calcification to the combined effects of ocean acidification and global warming. The analysis suggests that warm-water aragonitic corals are more resilient to climate change than previously thought, whereas marine organisms that precipitate calcitic skeletons are particularly vulnerable.

Rising ocean temperatures have reduced rates of coral calcification and increased rates of coral mortality, thereby negatively impacting the health of coral reef ecosystems. Nevertheless, the response of corals to thermal stress seems to vary spatially across the reef environment. Here, we show that between 1982 and 2008 in the western Caribbean Sea, skeletal extension within forereef colonies of the reef-building coral Siderastrea siderea declined with increasing seawater temperature, whereas extension rates of backreef and nearshore colonies were not impacted.

The reef and associated beachrock from certain Gulf of Mannar islands (Rameswaram, Kurusadai, Shingle and Appa Island) were studied to assess the diagenetic evidences. Sixty samples were collected from marine terraces and reef platforms. The samples comprised of coral rubbles, shell fragments and lithic fractions. The presence of corals in the form of framework or isolated patches on the reef flat suggests the rapid increase of accommodation and probably absence of terrigenous and siliciclastic inputs.

The world’s coral reefs are being degraded, and the need to reduce local pressures to offset the effects of increasing global pressures is now widely recognized. This study investigates the spatial and temporal dynamics of coral cover, identifies the main drivers of coral mortality, and quantifies the rates of potential recovery of the Great Barrier Reef. Based on the world’s most extensive time series data on reef condition (2,258 surveys of 214 reefs over 1985–2012), we show a major decline in coral cover from 28.0% to 13.8% (0.53% y−1), a loss of 50.7% of initial coral cover.