A large, shallow tidal lagoon on the north Adriatic coast, fed by six rivers, 30 km in length and about 5 km in width, with six main connections with the open sea and a number of small islands and sandbars along the coast. The area is rich in tidal mudflats, sand-dunes and large reedbeds. The deeper parts of the lagoon are covered by eel-grass Zostera and sea lettuce Ulva; the mudflats have cord-grass Spartina and Ruppia; permanently exposed banks have Salicornia and the dunes are vegetated by grasses (Agropyron, Ammophila), etc. There are fringing stands of Scirpus, Phragmites and Salix around the freshwater channels and rivers which enter the lagoon. The site also includes the final stretch (and mouth of) the Stella river, a lowland woodland, some agricultural areas, and the sea up to 5 m depth. Fishing, fish-farming, hunting, tourism and agriculture are the main uses of the area.
A very important site for waterbirds in winter (more than 100,000) as well as when breeding and on passage, with internationally important numbers of a wide variety of species. Species of global conservation concern that do not meet IBA criteria: Aythya nyroca (max. 1, winter). A total of 280 species recorded, of which about 100 breed. Winter waterbird counts are from January, from the period 1992-1994 unless otherwise stated.
Pressure/threats to key biodiversity
The main threats are: drainage; increased sedimentation of wetlands by mud from the dredging of channels; disturbance by tourists of breeding birds along sandbars; intensification of fish-farming; the extension of industrial and touristic infrastructure; illegal hunting; and motor-boating. Some or all of the site is covered by a management plan. There has been a regular census of wintering waterbirds and breeding gulls and herons since the 1970s. Since 1987 the Osservatori Faunistici di Gorizia e Udine has monitored breeding species regularly. Cygnus olor and Anser anser have been introduced as breeding species.
National Low International Low1,450 ha of IBA covered by Regional Nature Reserve (Foci dello Stella, 1,450 ha). 128 ha of IBA covered by Regional Nature Reserve (Valle Canal Novo, 128 ha). 340 ha of IBA covered by Regional Nature Reserve (Valle Cavanata, 340 ha). 1,400 ha of IBA covered by Special Protection Area (Marano Lagunare e Foce dello Stella, 1,400 ha). 243 ha of IBA covered by Special Protection Area (Valle Cavanata, 243 ha). 243 ha of IBA covered by Ramsar Site (Valle Cavanata, 243 ha).
BirdLife International (2022) Important Bird Areas factsheet: Grado and Marano lagoon. Downloaded from
http://www.birdlife.org on 26/11/2022.