As we’ve learned in class, corals are very important for building habitats for numerous species. This makes them very valuable to an ecosystem. One of the many contributing factors to this reef building process is a very important mutualistic relationship that coral has with zooxanthellae, an endosymbiotic phytoplankton. Coral are living organisms that have hundreds of corallites which contain polyps that obtain food via suspension feeding. Zooxanthellae reside within the corallites of lucky corals. Through this relationship, zooxanthellae receive shelter and nutrients such as nitrogen and phosphorus from the coral which help to efficiently photosynthesize. In return, coral receive a local oxygen supply, which is important in maintaining and growing its exoskeleton, carbon, and amino acids.

It has been shown that corals possessing zooxanthellae grow faster and are much healthier. However, when corals experience temperature stress, they expel their zooxanthellae. This phenomenon is called coral bleaching. When this happens, corals grow much slower, are unhealthier, and many times do not survive. Due to climate change, coral bleaching events are occurring more frequently and are having disastrous effects on ecosystems. These problems must be ­­­­­­­­addressed and mitigated immediately.

This is a photo of staghorn coral, a branching coral which possesses zooxanthellae. This photo was taken by me.