In front of the pineforest lies a bay of shallow waters. On the bay's sandy bottom we encounter Posidonia (Posidonia oceanica), a plant that grows only in clean water. In the underwater meadows of Posidonia a wide variety of marine fauna is alive and reproductive. There have been declines in the population of P. oceanica due to mechanical damage from trawling and boats, coastal development and eutrophication. Posidonia oceanica is a very slow growing species and takes a long time to recolonize areas from where it has been removed.In the rocky side of Cynosura peninsula, different underwater vegetation with higher algae is being developed.