One of the most important ecosystems of the island, hidden in the Erimitis Kassiopis, is the green wetland of Akoli, located about one and a half kilometers northeast of the settlement of Agios Stefanos. Together with Elos Erimitis and Vromolimni, they have been recorded by EKBY (Hellenic Centre for Habitats – Wetlands) under the name “Barbara Lagoon or Avlaki & Ag. Stephanos“.
It is a small coastal lake in an area that is not accessible by road and therefore has excellent conservation status. Access is possible via a path that starts from Agios Stefanos Sinion or Avlaki beach to the west or from the sea, by boat.
The wetland has no obvious connection to the sea but the water is brackish indicating a strong interaction.
The lake, during the Venetian occupation, was connected to the sea by a small open canal and probably functioned in the past as a fish farm.
To the east, it is separated from the sea by a narrow, enchanting beach while the other sides are overgrown with dense tree and shrub vegetation (holly, arbutus, myrtle, laurel, olive, etc.) of the semi-mountainous mass of Erimitis.
In the area there is a lot of garbage that is transported by the waves while in the summer months the beach is used by bathers. The predominant vegetation in the lake is moist, covering the largest area of mud and reeds. Regarding the fauna, there are fish, amphipods, snails, while in the area the presence of otters has been recorded. The construction of a large hotel unit is planned at the limits of the lake. If the plans are implemented then the lake will receive significant pressures. The wetland is included in the Presidential Decree for the protection of the small island wetlands of Greece.
According to the international ornithological organization IUCN, the lake is classified as an important area for birds, as they prefer it as a stop on their migratory journey, while it is also given value for the support of food chains, for its great biological variety and for recreation.