The site is a large, nutrient-rich freshwater lake, situated near the city of Moss. The lake is connected with the Oslofjord by the Mosse-elva river. Forestry is widespread; military activity mainly comprises low-flying planes from a nearby air base.
This is an important breeding site for Pandion haliaetus, with the highest known density of natural nests in Norway.
BirdLife International (2020) Important Bird Areas factsheet: Lake Vansjø. Downloaded from http://www.birdlife.org on 04/12/2020.