Claim: The Lake Tuusula has an area of 6.0 square kilometers and is under a protection program against eutrophication, a process that can result in oxygen depletion of the water body.
Evidence: The lake has an area of 6.0 square kilometres. The Lake Tuusulanjärvi Water Protection Association has taken action to save the lake from eutrophication effects since the early 1970s. This process may result in oxygen depletion of the water body after the bacterial degradation of the algae. 
This process may result in oxygen depletion of the water body after the bacterial degradation of the algae. 6 km (2.3 sq mi) The Lake Tuusulanjärvi Water Protection Association has taken action to save the lake from eutrophication effects since the early 1970s.