Utvärdering av den nationella databasen över åtgärder i vatten i fem svenska huvudavrinningsområden

Abstract: Restoration projects are planned and carried out in order to reduce the impact due to anthropogenic influence and to achieve at least good ecological status according to the EU Water Framework Directive. The resilience effort of such restorations is however ambiguous. The aim of this study was to evaluate the potential of follow up restoration measures in Swedish lakes and streams. In particular, we visualized the geographical spread of restoration measures in Sweden and quantified the different types of measures that were implemented so far. Further, we evaluated the extent of sampling of biological factors before and after the restoration measures have occurred. For the purpose of our study, we used the recently compiled national database of restoration measures in Swedish lakes and streams. We focused our study on five catchments; Emån and Mörrumsån in southern Sweden and Lögdeälven, Sävarån and Umeälven in the northern Sweden. The results show that the geographic spread of restoration measures differed between the northern and the southern catchments. The restoration measures in the northern catchments showed a distinct pattern with mainly fish ways and biotope treatment. This was not the case in the southern catchments, where a variety of measures was used. The results also showed that instead of proper follow-ups (including studies before the restoration measures were preformed), it was more common to only have subsequent sampling of biological factors. Hence, in most cases no conclusions on the actual effectiveness of the restoration measures can be drawn.