Ocean Acidifcation
Since the start of the Industrial Revolution about 150 years, ago, the amount of carbon dioxide (CO2) in the air has increased by one-third. About 25 percent of all of the CO2 emitted is absorbed by the oceans, another 25 percent is absorbed by plants and trees, and the remaining 50 percent stays in the atmosphere. As the oceans absorb CO2, their chemistry changes and they become more acidic. This makes it difficult for corals and other marine organisms to grow their skeletons and shells. The calcification rates of corals and other reef organisms have already begun to decrease. With increased CO2 in the water, coral may form weaker skeletons, making them more vulnerable to disease and destruction by storms.
Decreasing Biodiversity
Coral reefs harbour the highest biodiversity of any ecosystem globally. Despite covering less than 0.1% of the ocean floor, reefs host more than one quarter of all marine fish species, in addition to many other marine animals. Additionally, reefs provide a wide variety of ecosystem services such as subsistence food, protection from flooding and sustaining the fishing and tourism industries. Their disappearance will therefore have economic, social and health consequences.
