The Korission lagoon is a shallow (2 m) coastal ecosystem of great aesthetic and ecological importance, located in the southwest of Corfu Island, Greece. The area is included in the Natura 2000 network of protected areas and the wetland occupies 20 km2 (3) while the lagoon surface reaches of 5300 m and a mean width of 1500 m and lying parallel to the coastline with NW-SE direction. This area represent a complex and quite unmarred natural ecosystem.
It is the biggest wetland in the island and it is of significance importance due to the rare wild fauna hosted in the lagoon. Moreover, there are a lot of indigenous species of Mediterranean vegetation, growing in a narrow land strip separating the sea from the lake (4).
The lagoon. is separated from the open Ionian Sea by a strip of land, up to 200 m wide, which can be distinguished into two parts: a part southwards the channel which consists of uplifted Plio Pleistocene formations, including “old” sandy dunes with maximum elevations up to 15 m and an elongated deposit northwards the channel, that is essentially a beach barrier hosting lower recent sand dunes, reaching up to 2 meters height. In addition, at the foot of the “old” (pre Holocene) high dunes, modern dunes have been developed, whilst the presence of beach-rock formations along parts of the beach face indicates mixing of fresh and sea water (5).
The lagoon is connected to the sea by an artificial channel and its depth varies between 0.5 and 1.2 m. During summer it is hypersaline (salinity exceeds 50 psu) and surface temperature is 23.6–26.1EC, while DO values are 75–100%. On the other hand, in winter salinity falls to about 19 psu, surface temperature is 13.5–16.2EC and DO varies between 91 and 115%. Salt water intrusion occurs only to wells adjacent to the lagoon (3).
The lagoon bottom is covered by sea grass, an ideal food source for fish and contains large amounts of shell fish and crabs.
Northwestern Greece is one of the rainiest areas of the country in autumn and winter, but in summer it rarely rains. The water infiltrating the surface is spatially restricted within neogene and quaternary geological deposits, which overlay impermeable marls.
The terrain around the lagoon is generally smooth, and the elevation is low. Maximum elevation and slope are located at the norteasth of the lagoon (4).
References
(3) Diamantopouloua, M. Dassenakisa, A. Kastritisa, V. Tomara, V. Paraskevopouloua, S. Poulos E. (2008). Seasonal fluctuations of nutrients in a hypersaline Mediterranean lagoon Desalination 224 (2008) 271–279
(4) Tomara, V., Dassenakis M., Paraskevopouloua, S., Voulgaris N.(2010).Geo-environmental study of the Korission lagoon (Corfu).Procedings of the 9th international conference on Environmental Science and Thecnology. Rhodes Island, Greece, 1-3 September 2010
(5) Alexopoulos J.D.1, Tomara V., Vassilakis Em., Papadopoulos T.D., Dassenakis M., Poulos S., Voulgaris N., Dilalos S., Ghionis G., Goumas G., Pirlis E.(2007). A Contribution To Environmental Research of the Korission Coastal Wetland (Corfu isl., Greece), with the Application of Combined Geological and Geophysical Methods supported by Geographic Information Systems. 11th International Conference of the Geological Society of Greece: “Geoenvironment: past, present, future”, Athens, 2007.