Over-fertilization of lakes : How the municipalities in Sweden work with the environmental objective “no over-fertilization” of lakes

Over-fertilization of lakes happens when a large amount of nitrogen and phosphorus is added to the water. This has a negative impact on the water quality and the ecosystem since it often leads to massive phytoplankton growth, oxygen free bottom areas and fish dead for example. The purpose of this study was to investigate if, and how, the municipalities in Sweden work with the environmental objective “no over-fertilization” of lakes. The purpose was also to investigate if there is a difference between how municipalities in northern and southern Sweden work with the environmental objective “no over-fertilization” of lakes. The method used was a questionnaire, which was sent as a web-survey to all the 290 municipalities in Sweden. The result of this study indicates that most of the municipalities in Sweden work with the environmental objective “no over-fertilization” of lakes. Agriculture and wastewater seem to be the two largest sources that cause over-fertilization of lakes in both northern and southern Sweden. Although more than half of the municipalities in Sweden claim that they do not have enough resources to achieve the environmental objective “no over-fertilization” of lakes, which mostly depends on limited financials, personnel and expertise.