Today Lake Hornborga is one of Europe’s most important bird lakes but that has not always been the case. Before natural and cultural conservation interests were given credit the lake was drained in favor of agricultural purposes and left to overgrow. The lake was restored in the early 90’s which meant an increased area and higher water levels in the lake.
The water quality of the lake has been regularly tested in both the inlets and the outlet. This report sought to use some of this data to examine the retention of nitrogen and phosphorus in the lake, as well as the changes in retention due to the restauration. This was made by using the mean differences between the inlets and the outlet. The mean difference will indicate if less content is pouring out of the lake than in to the lake.
The analysis shows that the mean differences in total nitrogen between the inlets and the outlet have increased after the restauration. No distinction can be shown in most of the tests regarding the mean differences in total phosphorus. In fact one of the tests shows that the mean differences in total phosphorus between the inlets and the outlet have significantly decreased. These results indicates that the restauration of Lake Hornborga have increased its ability to reduce contents of nitrogen but not phosphorus. However, more comprehensive studies with more accurate methods are needed to prove these results.