GreekAgios Efstratios belongs to the protected areas of NATURA 2000 Network, as it has important habitats at its terrestrial and aquatic environment. Here you can meet the oak tree Quercus macrolepis, known as Valonia Oak, which has become a rare species in the Aegean. There are also some clusters of willow (Salix alba) and white poplar (Populus alba) near the settlement, while the biggest creeks are surrounded by oleanders (Nerium oleander) and chaste trees (Vitex agnus-castus). It is worth mentioning that the medicinal plant Melilotus elegans grows only on Agios Efstratios in all Greece. While at the seabed of the island you can meet in excellent condition the underwater meadows of Posidonia seagrass. The seagrass beds of the Mediterranean waters are a place of habitation and reproduction for many marine organisms, contributing at the same time to the coastal protection and erosion
