The Trondheim fjord is the third-longest fjord of Norway with its length of 126 km. It serves as a natural boundary between northern and southern Norway. The Trondheim fjord branches into many smaller fjords, the largest being Orkdalsfjorden in the southwest, Strindfjorden and Åsenfjorden in the east, and Beitstadfjorden in the northeast. it also has some islands, of which Ytterøya, near its head, is the largest. The fjord is bordered by a narrow strip of rich agricultural land that quickly gives way to steep mountains. Trondheim the major export city for the area and the third largest city in Norway lies along the southern shore of the fjord. The fjord is at Its maximum depth is 617 meters (2,024 ft), just inside of Agdenes.
On the way up the fjord, you pass Trondheim, Indre Fosen, Stjørdal, and Frosta before you reach the Innherred Region, with the cities of Levanger, Verdal, and Steinkjer at the top of the fjord.
Trondheim Fjord has a rich marine life, with both southern and northern species; It has been observed over 140 species and at least 90 these are different species of fish. The fjord has the largest biological production among Norway’s fjords. In recent years, deep water corals (Lophelia pertusa) were discovered in the fjord, not far from Trondheim. Several of the best salmon rivers in Norway runs out in the Trondheim Fjord. These include the Gaula river, the Orkla river, the Stjørdal river, and the Verdal river. The most common fish species you will catch here in the fjord are cod, pollock, catfish, ling, haddock, plaice, whiting, dogfish, mackerel, sea Trout, salmon, redfish, monk-fish and halibut.