comparing nutrient reference conditions in nordic streams

Reference conditions can be defined as the natural state of a water body. The concept is becoming increasingly important since climate and land use changes increase the pressures on our water bodies. However, determining nutrient reference conditions in areas that have been cultivated for centuries has proven difficult. BIOWATER scientists have therefore compared how the Nordic countries have approached the challenge. Our aim was to learn from each other and thereby reduce the uncertainties, and at the same time test the methods in Danish streams. Denmark has not yet established national nutrient reference conditions in streams.

In Nordic rivers for which pristine or near-pristine conditions can be found, nutrient reference concentrations, and the methods used to find them, are relatively comparable across borders. On the other hand, for river types where pristine conditions are scarce, both the methods and estimations of reference nutrient conditions vary across borders.

Our main conclusion is that this topic deserves a re-evaluation, so that we can arrive at harmonised and comparable river nutrient reference conditions across the Nordic borders.

We have presented our findings in a scientific paper (Ambio 49(11)) and summarised them in two policy briefs (one in English; another in Norwegian). Other national presentations of this topic are in the pipeline.