The Amvrakikos Gulf wetlands in western Greece form one of the country’s largest and most complex coastal ecosystems, where river deltas, lagoons and saltmarshes meet the Ionian Sea. Recognised as a Ramsar Wetland of International Importance since 21 August 1975, the area covers 23,649 hectares. It is also part of the Natura 2000 network and was placed on the Montreux Record in 1990 because human interventions altered its water balance and increased salinity.
Amvrakikos Gulf is a semi-enclosed marine basin of about 405 km², connected to the Ionian Sea through a narrow natural channel to the west. The Louros and Arachthos rivers flow into its northern sector, creating an extensive double delta with freshwater marshes, reedbeds and shallow lagoons. The town of Arta, with 21,286 inhabitants, lies about 10 km northeast of the wetland centre.
In this Copernicus Sentinel-2 image acquired on 1 March 2026, the lagoon waters near Arta appear in turquoise tones, contrasting with the regular bright-green pattern of inland agricultural fields. The image captures the transition from open marine waters to shallow coastal lagoons and mudflats that define the northern shoreline.
A semi-enclosed gulf shaped by rivers and lagoons
Around the Amvrakikos Gulf, lagoons such as Tsoukalio, Logarou, Rodia, Mazoma and Tsopeli form a chain of shallow basins, most of them less than 2 m deep and separated from the sea by sandy barrier spits. Tsoukalio, at 3,200 hectares, is one of the largest lagoons of its kind in the Mediterranean region. In total, lagoons cover about 60 km² along the coastline. The surrounding landscape is shaped by sedimentary deposits, limestone formations and alluvial plains.
Hydrology has been significantly modified. Since 1953, the Louros River has been regulated by a hydroelectric and irrigation dam, with a mean annual discharge below the dam of 468 million m³ between 1957 and 1995. The Arachthos River has been controlled by another irrigation dam since 1980, with a mean annual discharge of 1,390 million m³ between 1982 and 1995. These interventions, combined with irrigation demand, have affected freshwater inflows, sediment transport and salinity patterns. Despite these pressures, the wetland still plays a key role in flood attenuation and water quality maintenance.
Ecologically, the site includes freshwater marshes with extensive reedbeds, wet meadows dominated by Juncus species, and halophilous vegetation covering about 43 km². Saltmarsh communities of Arthrocnemum, Halocnemum and Salicornia are widespread, particularly around the Arachthos delta. Riparian gallery forests of Fraxinus, Ulmus, Populus and Salix survive in patches, covering about 2.5 km².
A refuge for pelicans, waterbirds and fisheries
The gulf supports 182 migratory bird species. It hosts one of Greece’s two breeding colonies of the globally threatened Dalmatian pelican, Pelecanus crispus, and serves as an important wintering site for the species. The double delta annually supports large wild duck populations, with a mean of 100,000 individuals and peaks up to 170,000. Breeding, staging and wintering waterbirds include herons, ibises, spoonbills, terns and raptors, while 70 migratory species present are listed in Annex I of the EU Birds Directive.
Fish diversity is also notable. Seven fish species recorded here are listed as threatened in Greece’s national Red Data Book, including Valencia letourneuxi and Barbus albanicus. Lagoon fisheries remain a central activity, with 688 tons recorded in 1995, alongside inland aquaculture units producing 1,920 tons and marine fish cultures producing 1,112 tons in the same year.
Approximately 5,500 people live within the Ramsar site, while about 76,000 inhabit the wider catchment. Fisheries, aquaculture, agriculture and grazing shape land use, and the area has archaeological interest linked to ancient Amvrakos and Nikopolis. Since 1990, conservation measures have placed restrictions on activities in order to maintain the ecological character of the wetland.
Copernicus Sentinel data provide regular, high-resolution observations of water colour, sediment plumes and vegetation patterns across the Amvrakikos Gulf. Such monitoring supports the assessment of habitat change, lagoon dynamics and land use in a wetland system where natural processes and human management remain closely intertwined.
Featured image credit: European Union, Copernicus Sentinel-2 imagery
