1. Global Change and Coral Reef Ecosystems
Global Climate Change (greenhouse effect)
Sea Level Rise

2. Coral Reefs
Coral Reefs grow in tropical seas in the sunlit zone/layer where there is mild wave action so that the reef does not tear apart, but the water is stirred enough to deliver efficient food and oxygen. Coral Reefs need nutrient poor, clear, warm, shallow water to grow.
Coral is built up from millions of skeletons from tiny animals called polyps, which are related to sea anemones.

3. Global Change Scenarios
Climate: It is predicted that if the present trend in greenhouse gas emissions don’t change, global mean temperatures are predicted to increase during the next century by about 0.3 degrees Celsius per decade(range ).By the year 2030 the net increase in temperature will amount to about 1 degree Celsius, and about 3 degrees Celsius by the year 2100.
Sea Level Rise: Under the Business as Usual Scenario, global sea level rise is predicted to average about 6cm per decade over the next century (range 3-10cm/decade).

4. Reef Responses to Environmental Changes
Temperature: Usually elevated temp. is a stressor that commonly leads to bleaching of corals and other zooanthellate organisms. And death if the dose is great enough. Temperature induced bleaching can occur in response to 1-2 day exposure to temp. 3-4 degrees above normal maximum, or several weeks to temps. 1-2 degrees elevation. However, at a given location a significant range of temperature responses appears among different colonies of same species. The differences between species we found to be, those with highest respiratory rates are more sensitive to elevated temp, as well as branching species instead of massive corals.

5. Reef Responses to Environmental Changes
Sea Level: Coral reef responses to sea level rise have to be considered on two scales; one is the possibility that existing reefs will drown due to being so deep that they cannot calcify, and two is that shallow sub tidal reef flats restricted by sea level rise will now have a chance to grow. On the other hand, deepening water subjects current coral communities to more physical wave stress. And could alter wave energy regimes.