One of the largest wetland areas in Greece is located in Messolongi. Actually, it is a wetland complex covering an area over 220,000 sq. km. This includes the Messolongi-Aitolikos lagoon (140,000 sq. km), the largest lagoon in Greece. This wetland expanse extends to the Gulf of Patras at a front of 50 km.
The main section of the wetland comprises three large lagoons: the southern, shallow lagoon, known as the Messolongi lagoon, extending up to the isle where the town of Aitoliko is situated; the northern deeper lagoon, known as the Aitolikos lagoon, and the eastern lagoon known as the lagoon of Kleisova. These lagoons, particularly the latter, provide natural fortification to the Messolongi area, given also the marshes located in the north. This fortification was particularly useful to the local population during the period of Greek Revolution.
The lagoons are not particularly deep; their maximum and average depths are 2 meters and 40 cm. respectively. The lagoon of Aitolikos, in the northern sector of Messolongi, is an exception with a maximum depth of 28 m. The entire area has been shaped by the alluvial deposits of two major rivers, the Acheloos and Euenos. The former discharges in the western sector and is responsible for the greatest alluvial activity in Greece, at least up to the period prior to the construction of three dams at Kremaston, Kastrakiou and Stratou locations. In the remote past the area featured large expanses of reverine forests of which only 600 sq. km. (the Forest of Fraxos) have survived in the area of Lesiniou to this date. Compared to Acheloos, the flow of Euenos, discharging in the eastern sector of the Messolongi area, is limited all year round.
Each year an inventory of avifauna takes place in the wetland complex giving a population size ranging from 25-35,000 birds, although the area can support larger populations. The wetlands of Messolongi constitute one of the most significant wintering locations, resting and feeding hotspots for migratory birds. The area is rich in fish fauna comprising (from records of catch) five basic species: stripped gray mullet, bass, bream, eel, and gudgeon. Fishing is mainly practiced by fish-traps installed at the exit of the lagoon near the sea. Each year the total catch amounts from 2,000 to 4,000 tons of fish representing a major resource for the local population.
The saltpan (Alyki) of Messolongi is one more income resource for the local population. Its annual production in salt covers 65% of salt production in Greece and suffices only for one half of the country’s salt demands. The white huge mounds of salt are a perfect refuge for migratory birds that feed on a microscopic organism (Artemia salina) proliferating in the flooded saltpans.
