The Site comprises six sub-sites, one on the island of Giske and five on the island of Vigra. The wetland system consists of extensive shallow marine bays with mud and sandflats and pebble shores, as well as a small area of dunes. The extent and the location of the wetlands make them internationally important, in particular for 220 recorded bird species. Large numbers of birds stage during their migrations, and in particular waders, making this the most important site for waders in the country. The area is also important for other wetland birds, including ducks, grebes and divers. It is used for recreation (walking, swimming, riding, birdwatching and non-commercial net fishing) as well as farming. Other human activities include conservation and education: a birdwatching station is established on Giske. Overgrowing due to changes in agriculture is the factor most affecting the area, as well as run-off of fertilizer. Planting of trees as shelter belts has also had a negative effect, while boat traffic and windsurfing also cause some disturbance.