Research Director LFI
- Bergen
bjba@norceresearch.no
+47 56 10 74 02
+47 992 05 951
Gas supersaturation
We carry out research on the impacts of gas supersaturation
Freshwater in nature is rarely saturated with gas beyond 100 percent. When there is more than 100 percent gas saturation in the water, the water is considered supersaturated with gas. A common cause of artificial gas supersaturation occurs when air is drawn into hydropower plants. The air then dissolves in the water under high pressure, and gas supersaturation occurs when the pressure is reduced after the water has passed through the turbine. Gas supersaturation can also occur downstream of dams during high water flow.
Contact person
Bjørn Torgeir Barlaup
Example of gas supersaturation in river outlet,, at Brokke power plant which regulates the river Otra in Agder region, Southern Norway.
Video: Sebastian Franz Stranzl
When gas supersaturation occurs, fish and benthic organisms are at risk of developing gas bubble disease, similar to decompression sickness in humans. The impact gradually diminishes with increasing distance from the power plant outlet and water depth.
Gas supersaturation can be monitored, avoided, and reduced. If power plants and dams are designed adequately, the risk of gas supersaturation can be minimized. However, even in existing power plants, gas supersaturation can be reduced.
Source:
Ulrich Pulg
Trout with injuries from gas bubble disease
Source:
Gaute Velle
s supersaturation is harmful to benthic organisms. The animals start to float upwards at gas supersaturation levels of 110% and subsequently die.
