Gullmarsfjord, Sweden
Main Contributors:
Johanna Yletyinen
Other Contributors:
Summary
Gullmarsfjord has a maximum depth of 118m with stagnant bottom water which is usually renewed with oxygen-rich deep water every spring. Hypoxia in Gullmarsfjord is episodic with a clear seasonal trend. Hypoxia evolves in autumnn and winter. It has caused mass mortality for instance in the winter of 1979-1980.
In 1997-1998 the hypoxic period was longer than ever before reported due to failed bottom water exchange in 1997. Since the water exchange didn't occur, the dissolved oxygen content continued to decrease. The fauna died at depths below 100m and was significantly reduced in depths between 80-100m. In 1998 the oxygen content slightly increased in January and a major bottom water renewal took place again in the spring.
Type of regime shift
Ecosystem type
- Marine & coastal
Land uses
- Conservation
Spatial scale of the case study
- Local/landscape (e.g. lake, catchment, community)
Continent or Ocean
- Europe
Region
- North Europe
Countries
- Sweden
Locate with Google Map
Key References
-
Nilsson H, Rosenberg R. Succession in marine benthic habitats and fauna in response to oxygen deficiency: analysed by sediment profile-imaging and by grab samples. Marine Ecology Progress Series 197, 139-149.
-
Rosenberg R, Agrenius S, Hellman B, Nilsson H, Norling K. 2002. Recovery of marine benthic habitats and fauna in a Swedish fjord following improved oxygen conditions. Marine Ecology Progress Series 234, 43-53.
Citation
Johanna Yletyinen.
Gullmarsfjord, Sweden.
In: Regime Shifts Database, www.regimeshifts.org.
Last revised 2012-01-11 14:08:21 GMT.
