Etolikos lagoon is located around the homonymous islet and the town.
It was formed by a seismic explosion and is therefore deep, reaching up to 28 meters and also fresh water. For this reason, it extracts fish larger than those in the neighboring lagoon of Messolonghi. It is a large and important wetland.
The famed fishery, Etolikos lagoon, is a huge habitat and forms the largest part of the valuable ecosystem defined by the Evinos estuary to the Acheloos estuary. The lagoon is a source of wealth and prosperity for both cities: Etoliko and Messolonghi, especially for the city of Etoliko, which was born in the heart of the lagoon and is an integral part of this large ecosystem, the largest in Europe.
All kinds of fish abound in the lagoon, especially the famous sea bream and mullet, from which the female "bafa" derives its roe, known as "Messolonghi roe". Most residents a few years ago were fishermen.
In the midst of a rare ecosystem, the Etoliko is surrounded by wetlands that host a huge variety of life forms. Over 250 different species of birds, including many rare and endangered species, survive, nest and spend their migrations here. This entire ecosystem has been included and protected by the Ramsar International Convention, and other international conventions aimed at conservation and rational management of wetlands.