Coral reefs were among the first ecosystems recognized as being vulnerable to the increasing ocean acidification. Ocean acidification is linked to the carbon dioxide that is released to the atmosphere and the reaction with seawater. The reaction of carbon dioxide with water forms weak carbonic acid (H2C03) that leads to increased acid levels in the ocean. This process uses the chemicals that coral reefs need to build their calcium skeleton thus interfering with their ability to grow normally. For instance, in the 1997-1998 El Nino-Southern Oscillation, 16% of all the tropical coral reefs died due to acidification. To date, most research has been on the effects caused by ocean acidification on the coral reefs that have shown their ability to produce huge amount of calcium carbonate. It has been estimated corals and calcifying macro-algae, which are the main coral reef building organisms, will calcify by 10-50% less by the year 2050 due to the numerous acidification of the ocean. The acidification not only affects the organisms alone, but the reefs they also build. However, some researchers say the response of coral reefs to acidity is changing. For instance, one study showed that some cold-water reefs to be less sensitive to the ph acidity change when the process occurred slowly. Being among the most threatened ecosystem in the world, coral reefs are surely facing the threat of becoming extinct due to the high ocean acidification rate. It is the high time we dealt more seriously with ocean acidification issue in order to reduce the acidity levels and enhance the survival of the coral reefs as they are facing extinction (Chivers, 516).
The research on coral reefs began in the early 1970s and 1780s when it focused on both biological and geological aspects. However, in the past two decades, coral reefs have come to face with their survival threat due to the continuing increase of carbon dioxide (CO2) concentrations in the atmosphere.