Amvrakikos Gulf is one of the largest semi-enclosed embayments in the Mediterranean Sea, located in northwestern Greece. At the northern border of the gulf, there are a complex lagoonal system and an extensive delta which is caused by the two main rivers (Arachthos and Louros). Amvrakikos Gulf is isolated from the Ionian Sea by a narrow, shallow strait, the Preveza channel (~600 m wide; 3 km long; 8.5 m mean depth).

The environmental state of Amvrakikos Gulf is highly influenced by the high river influx and evaporation rate, causing strong stratification of the water column throughout the year due to either salinity or temperature fluctuations. A well-stratified two-layer structure in the water column develops in the gulf, where a two-layer flow prevails at the entrance to the gulf, with brackish out-flowing water at the surface and saline inflowing water near the seabed. This morphology and water circulation pattern makes the Amvrakikos Gulf the only Mediterranean Sea fjord.

The western part of the gulf is suffering from seasonal hypoxia, whereas the eastern part is affected by seasonally anoxic conditions (Ferentinos et al. 2010; Kountoura & Zacharias 2011). Through time, the gulf has developed into a very sensitive environment that can easily be affected by climatic factors like temperature (Prandekou et al. 2022). The great variety of habitats occurring within the area are formed by the deltas of the Louros and Arachthos Rivers which flow into the north part of the gulf, forming 20 large and small lagoons, sand bars, salt marshes, reedbeds, wet meadows, mudflats, and riverine zones with remnants of riparian forest and hills between and among the lagoons. Its reedbeds and salt marshes, as well as the complex of lagoon systems comprise the most extensive in Greece. The lagoons (the largest and most important being Tsoukalio, Logarou, and Rodia) are characterised by high biological productivity. The seabed has a sandy to muddy substrate which is covered by seagrass meadows of Cymodocea nodosa in the shallower parts while the deeper part is muddy, which offer suitable habitat for different life history stages of marine fishes, including rays (Tuya et al. 2020; Moreno et al. 2022).

Amvrakikos Gulf is designated as a National Park of Greece, and includes two Natura 2000 sites (GR2110001, GR2110004) while the northern part is designated as a Ramsar site (Wetland of International Importance; 23,700 ha; 3GR009). The eastern mainland part of the gulf is also designated as the Amvrakikos Gulf Key Biodiversity Area (KBA 2023).

This Important Shark and Ray Area is benthopelagic and is delineated from inshore and surface waters (0 m) to 60 m depth based on the bathymetry of the area.