Bolstadfjorden

Bolstadfjorden is a 12 km long fjord in Vaksdal and Voss municipalities in Vestland county, Norway. The Bolstadfjorden is a branch of Veafjorden and a continuation of Vikafjorden. Vikafjorden meets Bolstadstraumen at Straume and the mouth of Bolstadfjorden. It is the innermost point of the fjord system surrounding the city of Bergen.
Bolstadfjorden is 160 m deep with a threshold of only 1.5 metres which creates a strong tidal current. Bolstadfjorden has a surface area of 7.1 km2 . There is a threshold at 35 metres creating two basins, the outer 4.6 km2 . The Vosso river flows into Bolstadfjorden and brings freshwater from a 1,500 km2 catchment area. Freshwater inflow peaks in May to June. Freshwater or brackish water on the surface obstructs circulation of the heavier saltwater leaving the saltwater in the deeper part deprived of oxygen. Measurements in April and August 2006 showed indicated that there was no oxygen at 50 metres or deeper. In April the layer of brackish water was about 5 metres deep, while in August the brackish water was 20 meters deep.

Wikipedia