Coral planting helps build a new home for marine life and restore the sea back to how it once was. PVC pipes play a major role in rebuilding the coral reefs. Think of it as a structure that you have to have before building a house. Reseachers have found that PVC pipe is the best choice for coral plantation, not only becuase the structure is simple and can support coral growth but also because pvc pipes have proven to be a stable material which can coexist with marine creatures. So we can say that they won't cause any harm toward the marine ecosystem. The steps to coral planting is easy. The picture below show the steps. 

Coral plantation is an activity that anyone can participate. Just sign up as a volunteer and you're good to go. It is also a great opportunity to help restore the sea to its beauty and meet people who are also interested in making the world a better place!

Credits: http://www.solvay.com/en/asking-more/Rehabilitating-coral-reefs-with-PVC-piping.html