Macroalgal calcification and the effects of ocean acidification and global warming

Abstract

Calcification by calcified marine macroalgae is crucial to algal growth and the formation and maintenance of coral reefs. It involves complex processes, such as the uptake, transport and storage of Ca2+, HCO3– or CO32–, and the formation of crystals responsible for calcium deposition. Calcification is vulnerable to changes in global climate, including ocean acidification and warming. Studies investigating the mechanisms of macroalgal calcification are limited and restricted to physiological processes; however, the use of new approaches, such as genomics, provides avenues for new understandings. Here, we review the literature on macroalgal calcification from physiological to molecular levels and present a list of key issues that need to be resolved in order to understand the mechanism of calcification. This review offers insights into the potential effects of changing climate conditions on algal calcification to provide an accurate prediction of future changes in reef ecosystems.