Reefs as net carbon sources or net carbon sink?

Debates on the role of coral reefs, whether as a carbon source or carbon sink, started in the early 1990s. These debates continue until today, especially with the increasing concern of global climate change and global warming. Although several studies have been done to calculate the flux of pCO2 between reefs and the atmosphere, there is no clear evidence whether the coral reef is a source or sink. This paper reviews the development of studies of carbon flux of reefs, with how pCO2 is different in several reef type habitats and assess if geographical latitude of reef affected the flux of CO2. In general, coral reefs act as a carbon source to the atmosphere. However, this role depends on the habitat type of reef, whether they are coral-dominated or algal-dominated reef. The geographical location of reefs may also affect CO2 flux between reefs and the atmosphere. [ABSTRACT FROM AUTHOR]