Coral bleaching is a prevalent issue that occurs in the ocean that can eventually lead to coral death. Because of increasing ocean acidification and rising ocean temperatures, many coral are beginning to expel the algae that they rely on for food. Coral have a mutualistic relationship with the algae that live inside them. When the ocean conditions change, the coral expunges the algae that live inside them, which causes the coral to be bleached white, hence where the term “coral bleaching” comes from.

 

The main culprit behind coral bleaching is the increasing CO2 emissions in the world as it can directly cause ocean temperatures to rise and ocean acidification. Since CO2 is a greenhouse gas, this will cause the global temperature to rise. Because of this increased temperature, the normal temperature that coral thrive in, will be lost and the coral will begin to bleach. A one degree increase in temperature for just four weeks can cause bleaching. Alongside this, the increased CO2 emissions will be absorbed by the oceans which will increase the pH. This will inhibit calcification of the coral skeletons.