The main area of interest can be divided into four island groups: Stora Nassac.400 closely spaced rocky islets with little or no vegetation. The largest island has maritime Betula forest whilst others support Juniperus. Wet grasslands are also present. Lilla Nassasmaller area than Stora Nassa but with islands more spread out and with very little vegetation. Gillögaflat islands in shallow waters with abundant cover and submerged offshore reefs. Svenska Högarnaa flat island with Juniperus, and heather Calluna. The archipelago is largely uninhabited but during the summer is a popular leisure (boating) area.
This is a very important breeding area for seaducks, waders, gulls and seabirds.
Pressure/threats to key biodiversity
American mink Mustela vison are a threat to breeding birds. Recreational activities may disturb breeding birds.
National Partial International HighIBA overlaps with Nature Reserve (3,400 ha); large areas are also designated as Bird Sanctuaries. 9,100 ha of IBA covered by Ramsar Site (Stockholm, outer archipelago, 15,000 ha). IBA overlaps with Special Protection Area.
BirdLife International (2022) Important Bird Areas factsheet: Archipelago of Stockholm. Downloaded from
http://www.birdlife.org on 20/01/2022.