Corals are important because they are the primary builders of large calcium carbonate structures that make up the reef ecosystem. Recent coral reef degradation is quite possibly caused by climate change. Emission of fossil fuels into the atmosphere increases carbon 'dioxide (C0₂) concentrations, ... Show moreCorals are important because they are the primary builders of large calcium carbonate structures that make up the reef ecosystem. Recent coral reef degradation is quite possibly caused by climate change. Emission of fossil fuels into the atmosphere increases carbon 'dioxide (C0₂) concentrations, which can affect coral reefs in two ways. One way is by the greenhouse effect. As temperature increases in the atmosphere, some of the heat is transferred to the surface of the ocean. When sea-surface temperatures become too warm, corals experience bleaching. The second effect is seawater chemistry changes due to absorption of CO, in the oceans. As more CO, is driven into the oceans, seawater chemistry changes so that less carbonate ion (CO₃) is available to the coral for calcification (i.e., precipitation of calcium carbonate, (CaCO₃). As calcification decreases, the coral's skeleton weakens. In order to examine this effect, we produced an aquarium model to simulate how coral calcification is affected by the increase in atmospheric C0₂, as well as by increases in sea-surface temperature. This model has helped us determine how corals may be affected in the future if CO₂ levels and temperature continue to rise. Show less
