Stigfjorden is a large, shallow marine bay fringed by meadows and deciduous forests with many islands. The sea bed is covered by Zostera and Potamogeton species, and marine currents help keep the area ice-free for long periods during the winter. The shallow water in the northern part of the Site holds one of the richest bird colonies of this coast and provides shelter and food for waterbirds. It is a moulting site for common goldeneye Bucephala clangula and an important staging and foraging site for nationally threatened species such as bar-tailed godwit Limosa lapponica, ruff Philomachus pugnax and common eider Somateria mollissima. The area supports an important fishery, while other activities include livestock grazing, boating, and swimming. Continuation of traditional grazing is important for maintaining the ecological character of the meadows. In 2017, the Site was extended by nearly 400 hectares to include a large area of open waters to the east.