The Biotest basin is an approximately 90 hectare embedded water reservoir that receives heated cooling water from Forsmark's nuclear power plant. The water is around eight degrees warmer than in the surrounding sea, but apart from the higher temperature the environment is natural. The Biotest basin can thus be likened to a time machine for future oceans and is an exciting environment for research on what will happen when the water temperature rises in the future.
History of the Biotest Lake
The Biotest basin was completed in 1977 and warm water from the nuclear power plant began flowing through the basin in the spring of 1980. Two years later, in 1982, the warm water discharge from the plant reached its maximum, at 90,000 liters per second. Today (2020), just over 100,000 liters of cooling water are discharged per second, and the water in the Biotest basin is approximately 8°C warmer than the surrounding coastal water.
Free passage for fish since 2004
Until spring 2004, the discharge point of the Biotest basin was equipped with a grid, with the aim of preventing fish from moving between the basin and the surrounding coastal areas. In 2004, the grid was removed and since then fish can move freely between the areas.
Biological investigations and climate research
In order to investigate how the warm water affects the marine environment in the Biotest basin and in the Bothnian Sea, we at the Department of Aquatic Resources carry out regular checks. We carry out test fishing with gillnets, we monitor benthic animals and we study coastal birds in the area. We compile the results of the investigations in annual reports and in-depth reports approximately every five years.
In the Biotest basin, we carry out research on fish growth in warmer water. Please read more in the news "Warming gradually leads to higher growth rates of small but not large fish".
Questions about the Biotest basin
Do you have any questions or would you like to use the Biotest basin for scientific projects? Please contact Anders Adill.
