A review on ecological response of coral reefs to global warming and oceanic acidification

Tropical reefs are anti-wave structures composed of corals, algae and other reef-building organisms. They are one of the world's major carbon banks and an important window to observe the linkages and interactions between the mid- to high-latitude environmental processes and tropical oceans. In the past decades, with the significant acidification and warming of global oceans, the tropical coral reefs are seriously under threat. Ocean acidification is a factor which may significantly affect coral calcification rates, inhibit the development of coral larvae, and trigger the dissolution of coral reefs. And high temperature may cause the rising of sea temperature, coral bleaching and inhibit the self-repair of coral reefs. In addition, both of the two factors may induce changes in the community structure of coral reefs. In response to the changes in these environmental factors, corals can resist heat stress to a certain extent by changing the types of symbiotic algae and regulating gene expression. However, if the emission of greenhouse gases is not properly controlled in the near future, most coral reefs on the Earth may face complete elimination by the end of this century. A more comprehensive understanding of coral reefs’ response to the key factors in the climate system change, including higher temperature and acidification, is required to cope better with changes of coral reefs in different possible scenarios in the future. The study of reef depositional sequences may provide key insights into the long-term evolving patterns of coral reefs, and serve as a valuable supplement for modern observations.