Arkelstorpsviken i Oppmannasjön - Källor till fosfor och kväve, status och åtgärdsförslag

Sammanfattning: Arkelstorpsviken has experienced severe eutrophication during several decades along with toxic algal blooms that have made the water unsuitable for exposure. While the rest of lake Oppmannasjön has been classified according to biological, physical-chemical and hydromorphological factors, Arkelstorpsviken remains unclassified. Relevant reports, government documents and sampling results have been used from within the lake and its catchment area to identify sources of phosphorus and nitrogen. The aim of my study is to highlight the state of Arkelstorpsviken as well as to serve as a basis for future sampling and measures being taken. Results show that Arkelstorpsviken is highly eutrophic and the source is mainly internal loading but more measures must also be taken to decrease the external load. Due to Arkelstorpsviken being extremely shallow, with a mean depth of 1m, measures taken to decrease eutrophication must take into account the high probability of resuspension if sediments are disturbed. Phosphorus from agriculture and wastewater should decrease and the internal load in Arkelstorpsviken needs to be managed with methods such as precipitation with ferric chloride or biomanipulation and the establishment of macrophytes to stabilize sediments.