The site comprises a 50 km stretch along the north-eastern side of Trondheimsfjord, the third largest fjord in Norway, from south of Levanger to north of Steinkjer. This is a network of 10-12 key wetlands, some of which would qualify as IBAs individually. The main habitats are extensive shallow subtidal areas, intertidal mudflats and the mouths of two large rivers, Verdalselva and Steinkjerelva, as well as those of several smaller ones. Land surrounding the fjord is mainly cultivated, but semi-natural meadows remain intact in a few places. The site includes `Gjørv, Borgenfjorden', an IBA that was listed individually (as site NO030) in the previous European IBA inventory (Grimmett and Jones 1989).
Most or all of the Svalbard population of Anser brachyrhynchus (30,000 birds) probably stages in the area in May during spring migration, thus this is probably one of the most important stop-over sites in Norway for the species (c.3,000 stage at Gjørv [Borgenfjorden] alone). The geese forage on the mudflats, but spend the nights on the water. The area is notable as a staging area for other seabirds, waders and ducks as well. Seaduck such as Melanitta nigra, M. fusca, Bucephala clangula and Clangula hyemalis occur in large numbers on spring migration. The estimated number of geese, ducks, waders and gulls staging in the whole area is 35,000-60,000.
BirdLife International (2021) Important Bird Areas factsheet: Inner Trondheimsfjord. Downloaded from http://www.birdlife.org on 25/01/2021.