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Case Studies (332)
Skive Fjord, Denmark
Main Contributors:
Johanna Yletyinen
Other Contributors:
Summary
Hypoxia and anoxia are to a certain scale natural phenomena in fjords. The causes of hypoxia in Denmark are related to increased nutrient loads and natural physical factors (e.g. weather) affecting the timing and duration of hypoxia.
Type of regime shift
Ecosystem type
- Marine & coastal
- Freshwater lakes & rivers
Land uses
- Fisheries
Spatial scale of the case study
- Local/landscape (e.g. lake, catchment, community)
Continent or Ocean
- Europe
Region
- Northern Europe
Countries
- Denmark
Locate with Google Map
Key References
-
Karlson K, Rosenberg R, Bonsdorff E. 2002. Temporal and spatial large-scale effects of eutrophication and oxygen deficiency on benthic fauna in Scandinavian and Baltic waters: A review. Oceanography and Marine Biology 40, 427-489.
Citation
Johanna Yletyinen.
Skive Fjord, Denmark.
In: Regime Shifts Database, www.regimeshifts.org.
Last revised 2012-01-12 09:32:40 GMT.
Published in
Case Studies
Skagerrak Coast
Main Contributors:
Johanna Yletyinen
Other Contributors:
Summary
Since the early 1980s, more or less widespread hypoxia has been observed nearly every autumn in Danish coastal waters. Water exchange in Skagerrak is limited and hypoxic conditions in deep basin are common, because water renewal, which takes place only once a year, causes stagnation period with hypoxia in the winter. Several fjords on the Swedish and Norwegian Skagerrak coast have shown negative trends in dissolved oxygen content, and some of them lack benthic fauna in the deeper parts for several months or more. Swedish fjords of the Skagerrak coast experience hypoxia and anoxia for most of the year. In Norway, for instance in Oslofjord, the benthic fauna has suffered from mortality and behavioral changes. Since around 1960-70s, dissolved oxygen content has reclined in Oslofjord. Improvements in sewage treatment and discharge practices have been made.
Type of regime shift
Ecosystem type
- Marine & coastal
Land uses
- Fisheries
Spatial scale of the case study
- Sub-continental/regional (e.g. southern Africa, Amazon basin)
Continent or Ocean
- Europe
Region
- Northern Europe
Countries
- Norway
- Sweden
- Denmark
Locate with Google Map
Key References
-
Conley J, Carstensen J, Ærterbjerg G, Christensen PB, Dalsgaard T, Hansen J, Josefsen A. 2007. Long-term changes and impacts of hypoxia in Danish coastal waters. Ecological Applications 17, 165-184.
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Rabalais N (Ed.), Turner RE (Ed.). 2002. Coastal hypoxia: Consequences for living resources and ecosystems (Coastal and estuarine sciences, 58). Amer Geophysical Union, Washington
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Rosenberg R, Cato I, Förlin L, Grip K, Rorhe J. Marine environment quality assessment of the Skagerrak - Kattegat. Journal of Sea Research 35, 1-8.
Citation
Johanna Yletyinen.
Skagerrak Coast.
In: Regime Shifts Database, www.regimeshifts.org.
Last revised 2012-01-12 09:31:37 GMT.
Published in
Case Studies
Roskilde Fjord, Denmark
Main Contributors:
Johanna Yletyinen
Other Contributors:
Summary
Since the early 1980s, more or less widespread hypoxia has been observed nearly every autumn in Danish coastal waters. The causes of hypoxia in Denmark are related to increased nutrient loads and natural physical factors (e.g. weather) affecting the timing and duration of hypoxia.
The most severe and widespread open waters hypoxia occurred in 2002 when a combination of unusually high winter precipitation and unusually calm, warm weather in late summer and autumn. Hypoxic events in Danish estuaries are not in phase with the open waters; the most severe hypoxic episode in estuaries was reported in 1997 when parts of the Mariager Fjord turned completely anoxic. Roskilde Fjord has been particularly negative affected by the coastal Kattegat hypoxia.
The response of marine benthic macrofaunal communities to seasonal hypoxia in coastal Denmark is a collapse or mass mortality.
The most severe and widespread open waters hypoxia occurred in 2002 when a combination of unusually high winter precipitation and unusually calm, warm weather in late summer and autumn. Hypoxic events in Danish estuaries are not in phase with the open waters; the most severe hypoxic episode in estuaries was reported in 1997 when parts of the Mariager Fjord turned completely anoxic. Roskilde Fjord has been particularly negative affected by the coastal Kattegat hypoxia.
The response of marine benthic macrofaunal communities to seasonal hypoxia in coastal Denmark is a collapse or mass mortality.
Type of regime shift
Ecosystem type
- Marine & coastal
Land uses
- Timber production
Spatial scale of the case study
- Local/landscape (e.g. lake, catchment, community)
Continent or Ocean
- Europe
Region
- The Baltic Sea
Countries
- Denmark
Locate with Google Map
Key References
-
Clarke A, Juggins S, Conley D. 2003. A 150-year reconstruction of the history of coastal eutrophication in Roskilde Fjord, Denmark. Marine Pollution Bulletin 46, 1615-1618.
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Conley J, Carstensen J, Ærterbjerg G, Christensen PB, Dalsgaard T, Hansen J, Josefsen A. 2007. Long-term changes and impacts of hypoxia in Danish coastal waters. Ecological Applications 17, 165-184.
-
Karlson K, Rosenberg R, Bonsdorff E. 2002. Temporal and spatial large-scale effects of eutrophication and oxygen deficiency on benthic fauna in Scandinavian and Baltic waters: A review. Oceanography and Marine Biology 40, 427-489.
Citation
Johanna Yletyinen.
Roskilde Fjord, Denmark.
In: Regime Shifts Database, www.regimeshifts.org.
Last revised 2011-12-19 15:30:53 GMT.
Published in
Case Studies
Ringkøbing Fjord, Denmark
Main Contributors:
Johanna Yletyinen
Other Contributors:
Summary
Ringkoping Fjord is actually a coastal lagoon. Since the early 1980s, more or less widespread hypoxia has been observed nearly every autumn in Danish coastal waters. The causes of hypoxia in Denmark are related to increased nutrient loads and natural physical factors (e.g. weather) affecting the timing and duration of hypoxia.
The most severe and widespread open waters hypoxia occurred in 2002 when a combination of unusually high winter precipitation and unusually calm, warm weather in late summer and autumn. Hypoxic events in Danish estuaries are not in phase with the open waters; the most severe hypoxic episode in estuaries was reported in 1997 when parts of the Mariager Fjord turned completely anoxic.
The response of marine benthic macrofaunal communities to seasonal hypoxia in coastal Denmark is a collapse or mass mortality.
The most severe and widespread open waters hypoxia occurred in 2002 when a combination of unusually high winter precipitation and unusually calm, warm weather in late summer and autumn. Hypoxic events in Danish estuaries are not in phase with the open waters; the most severe hypoxic episode in estuaries was reported in 1997 when parts of the Mariager Fjord turned completely anoxic.
The response of marine benthic macrofaunal communities to seasonal hypoxia in coastal Denmark is a collapse or mass mortality.
Type of regime shift
Ecosystem type
- Marine & coastal
Land uses
- Fisheries
Spatial scale of the case study
- Local/landscape (e.g. lake, catchment, community)
Continent or Ocean
- Europe
Region
- North Sea
Countries
- Denmark
Locate with Google Map
Key References
-
Conley J, Carstensen J, Ærterbjerg G, Christensen PB, Dalsgaard T, Hansen J, Josefsen A. 2007. Long-term changes and impacts of hypoxia in Danish coastal waters. Ecological Applications 17, 165-184.
-
Karlson K, Rosenberg R, Bonsdorff E. 2002. Temporal and spatial large-scale effects of eutrophication and oxygen deficiency on benthic fauna in Scandinavian and Baltic waters: A review. Oceanography and Marine Biology 40, 427-489.
Citation
Johanna Yletyinen.
Ringkøbing Fjord, Denmark.
In: Regime Shifts Database, www.regimeshifts.org.
Last revised 2011-12-19 15:32:45 GMT.
Published in
Case Studies
Odense Fjord, Denmark
Main Contributors:
Johanna Yletyinen
Other Contributors:
Summary
Hypoxia and anoxia are to a certain scale natural phenomena in many deep fjords. In Odense Fjord, high biomass of algae and eutrophication has contributed to hypoxia. Since the early 1980s, more or less widespread hypoxia has been observed nearly every autumn in Danish coastal waters. The causes of hypoxia in Denmark are related to increased nutrient loads and natural physical factors (e.g. weather) affecting the timing and duration of hypoxia. Hypoxic events in Danish estuaries are not in phase with the open waters; the most severe hypoxic episode in estuaries was reported in 1997 when parts of the Mariager Fjord turned completely anoxic. The response of marine benthic macrofaunal communities to seasonal hypoxia in coastal Denmark is a collapse or mass mortality.
Type of regime shift
Ecosystem type
- Marine & coastal
Land uses
- Fisheries
Spatial scale of the case study
- Local/landscape (e.g. lake, catchment, community)
Continent or Ocean
- Europe
Region
- North Europe
Countries
- Denmark
Locate with Google Map
Key References
-
Conley J, Carstensen J, Ærterbjerg G, Christensen PB, Dalsgaard T, Hansen J, Josefsen A. 2007. Long-term changes and impacts of hypoxia in Danish coastal waters. Ecological Applications 17, 165-184.
-
Karlson K, Rosenberg R, Bonsdorff E. 2002. Temporal and spatial large-scale effects of eutrophication and oxygen deficiency on benthic fauna in Scandinavian and Baltic waters: A review. Oceanography and Marine Biology 40, 427-489.
-
Lundholm N, Clarke A, Ellegaard M. 2010. A 100-year record of changing Pseudo-nitzschia species in a sill-fjord in Denmark related to nitrogen loading and temperature. Harmful Algae 9, 449-475.
Citation
Johanna Yletyinen.
Odense Fjord, Denmark.
In: Regime Shifts Database, www.regimeshifts.org.
Last revised 2012-01-12 11:39:18 GMT.
Published in
Case Studies
Nivå Bugt, Denmark
Main Contributors:
Johanna Yletyinen
Other Contributors:
Summary
Since the early 1980s, more or less widespread hypoxia has been observed nearly every autumn in Danish coastal waters. The causes of hypoxia in Denmark are related to increased nutrient loads and natural physical factors (e.g. weather) affecting the timing and duration of hypoxia.
The most severe and widespread open waters hypoxia occurred in 2002 when a combination of unusually high winter precipitation and unusually calm, warm weather in late summer and autumn. Hypoxic events in Danish estuaries are not in phase with the open waters; the most severe hypoxic episode in estuaries was reported in 1997 when parts of the Mariager Fjord turned completely anoxic.
The response of marine benthic macrofaunal communities to seasonal hypoxia in coastal Denmark is a collapse or mass mortality.
The most severe and widespread open waters hypoxia occurred in 2002 when a combination of unusually high winter precipitation and unusually calm, warm weather in late summer and autumn. Hypoxic events in Danish estuaries are not in phase with the open waters; the most severe hypoxic episode in estuaries was reported in 1997 when parts of the Mariager Fjord turned completely anoxic.
The response of marine benthic macrofaunal communities to seasonal hypoxia in coastal Denmark is a collapse or mass mortality.
Type of regime shift
Ecosystem type
- Marine & coastal
Land uses
- Fisheries
Spatial scale of the case study
- Local/landscape (e.g. lake, catchment, community)
Continent or Ocean
- Europe
Region
- The Baltic Sea
Countries
- Denmark
Locate with Google Map
Key References
-
Conley J, Carstensen J, Ærterbjerg G, Christensen PB, Dalsgaard T, Hansen J, Josefsen A. 2007. Long-term changes and impacts of hypoxia in Danish coastal waters. Ecological Applications 17, 165-184.
-
Lundholm N, Clarke A, Ellegaard M. 2010. A 100-year record of changing Pseudo-nitzschia species in a sill-fjord in Denmark related to nitrogen loading and temperature. Harmful Algae 9, 449-475.
Citation
Johanna Yletyinen.
Nivå Bugt, Denmark.
In: Regime Shifts Database, www.regimeshifts.org.
Last revised 2011-12-19 15:33:03 GMT.
Published in
Case Studies
Nissum Fjord, Denmark
Main Contributors:
Johanna Yletyinen
Other Contributors:
Summary
Hypoxia and anoxia are to a certain scale natural phenomena in many deep fjords. Since the early 1980s, more or less widespread hypoxia has been observed nearly every autumn in Danish coastal waters. The causes of hypoxia in Denmark are related to increased nutrient loads and natural physical factors (e.g. weather) affecting the timing and duration of hypoxia. Hypoxic events in Danish estuaries are not in phase with the open waters; the most severe hypoxic episode in estuaries was reported in 1997 when parts of the Mariager Fjord turned completely anoxic.
The response of marine benthic macrofaunal communities to seasonal hypoxia in coastal Denmark is a collapse or mass mortality.
The response of marine benthic macrofaunal communities to seasonal hypoxia in coastal Denmark is a collapse or mass mortality.
Type of regime shift
Ecosystem type
- Marine & coastal
Land uses
- Fisheries
Spatial scale of the case study
- Local/landscape (e.g. lake, catchment, community)
Continent or Ocean
- Europe
Region
- Northern Europe
Countries
- Denmark
Locate with Google Map
Key References
-
Conley J, Carstensen J, Ærterbjerg G, Christensen PB, Dalsgaard T, Hansen J, Josefsen A. 2007. Long-term changes and impacts of hypoxia in Danish coastal waters. Ecological Applications 17, 165-184.
-
Karlson K, Rosenberg R, Bonsdorff E. 2002. Temporal and spatial large-scale effects of eutrophication and oxygen deficiency on benthic fauna in Scandinavian and Baltic waters: A review. Oceanography and Marine Biology 40, 427-489.
-
Lundholm N, Clarke A, Ellegaard M. 2010. A 100-year record of changing Pseudo-nitzschia species in a sill-fjord in Denmark related to nitrogen loading and temperature. Harmful Algae 9, 449-475.
Citation
Johanna Yletyinen.
Nissum Fjord, Denmark.
In: Regime Shifts Database, www.regimeshifts.org.
Last revised 2011-12-19 15:33:12 GMT.
Published in
Case Studies
Limfjorden, Denmark
Main Contributors:
Johanna Yletyinen
Other Contributors:
Summary
Hypoxia in Limfjorden is seasonal and has caused mass mortality of benthos (with annual recolonization). In 1990s it was marked that during the last 80 years, fish yields had been decreasing in Limfjorden and benthos seemed to display similar trends. It has been found out that at least in three occassions mass mortality has likely been caused by oxygen deficiency.
Type of regime shift
Ecosystem type
- Marine & coastal
- Freshwater lakes & rivers
Land uses
- Fisheries
Spatial scale of the case study
- Local/landscape (e.g. lake, catchment, community)
Continent or Ocean
- Europe
Region
- Northern Europe
Countries
- Denmark
Locate with Google Map
Key References
-
Hylleberg J. 1993. Extinction and immigration of benthic fauna, the value of historical data from Limfjorden, Denmark. Ist. Sci. Ambientali Mar., Santa Margeherita Ligure, 43-70.
Citation
Johanna Yletyinen.
Limfjorden, Denmark.
In: Regime Shifts Database, www.regimeshifts.org.
Last revised 2011-12-19 15:33:17 GMT.
Published in
Case Studies
Køge Bugt, Denmark
Main Contributors:
Johanna Yletyinen
Other Contributors:
Summary
Since the early 1980s, more or less widespread hypoxia has been observed nearly every autumn in Danish coastal waters. The causes of hypoxia in Denmark are related to increased nutrient loads and natural physical factors (e.g. weather) affecting the timing and duration of hypoxia.
The most severe and widespread open waters hypoxia occurred in 2002 from a combination of unusually high winter precipitation and unusually calm, warm weather in late summer and autumn. Hypoxic events in Danish estuaries are not in phase with the open waters; the most severe hypoxic episode in estuaries was reported in 1997 when parts of the Mariager Fjord turned completely anoxic.
The response of marine benthic macrofaunal communities to seasonal hypoxia in coastal Denmark is a collapse or mass mortality.
The most severe and widespread open waters hypoxia occurred in 2002 from a combination of unusually high winter precipitation and unusually calm, warm weather in late summer and autumn. Hypoxic events in Danish estuaries are not in phase with the open waters; the most severe hypoxic episode in estuaries was reported in 1997 when parts of the Mariager Fjord turned completely anoxic.
The response of marine benthic macrofaunal communities to seasonal hypoxia in coastal Denmark is a collapse or mass mortality.
Type of regime shift
Ecosystem type
- Marine & coastal
Land uses
- Fisheries
Spatial scale of the case study
- Local/landscape (e.g. lake, catchment, community)
Continent or Ocean
- Europe
Region
- The Baltic Sea
Countries
- Denmark
Locate with Google Map
Key References
-
Conley J, Carstensen J, Ærterbjerg G, Christensen PB, Dalsgaard T, Hansen J, Josefsen A. 2007. Long-term changes and impacts of hypoxia in Danish coastal waters. Ecological Applications 17, 165-184.
-
Karlson K, Rosenberg R, Bonsdorff E. 2002. Temporal and spatial large-scale effects of eutrophication and oxygen deficiency on benthic fauna in Scandinavian and Baltic waters: A review. Oceanography and Marine Biology 40, 427-489.
Citation
Johanna Yletyinen.
Køge Bugt, Denmark.
In: Regime Shifts Database, www.regimeshifts.org.
Last revised 2011-12-19 15:33:21 GMT.
Published in
Case Studies
Kattegat, Sweden & Denmark
Main Contributors:
Johanna Yletyinen
Other Contributors:
Summary
Hypoxia was first recorded in 1981 when large areas of the Kattegat had widespread severe hypoxia. Seasonal or more or less permanent hypoxia has resulted in benthic mortality. Hypoxia dominates the south-eastern part but occurs occasionally everywhere. In the southeast (open Kattegat) hypoxia is caused by increased input of nutrients and stratification since 1980s with negative effects on benthic animals and commercial fish species in most of the years.
Type of regime shift
Ecosystem type
- Marine & coastal
Land uses
- Fisheries
Spatial scale of the case study
- Sub-continental/regional (e.g. southern Africa, Amazon basin)
Continent or Ocean
- Europe
Region
- The Baltic Sea
Countries
- Sweden
- Denmark
Locate with Google Map
Key References
-
Andresson L, Rydberg L. 1988. Trends in nutrient and oxygen conditions within the Kattegat: Effects on local nutrient supply. Estuarine, Coastal and Shelf Science 26, 559-579.
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Conley J, Carstensen J, Ærterbjerg G, Christensen PB, Dalsgaard T, Hansen J, Josefsen A. 2007. Long-term changes and impacts of hypoxia in Danish coastal waters. Ecological Applications 17, 165-184.
-
Karlson K, Rosenberg R, Bonsdorff E. 2002. Temporal and spatial large-scale effects of eutrophication and oxygen deficiency on benthic fauna in Scandinavian and Baltic waters: A review. Oceanography and Marine Biology 40, 427-489.
Citation
Johanna Yletyinen.
Kattegat, Sweden & Denmark.
In: Regime Shifts Database, www.regimeshifts.org.
Last revised 2011-12-19 16:39:34 GMT.
Published in
Case Studies
