Ecological status in river Sjoa and Vinstra 2012 - 2016

Summary

Ecological state of 6 locations in the rivers Sjoa and Vinstra, in county Oppland, Norway, has been classified in accordance to the Water Framework Directive. The results are based on samples collected in 2012, 2014 and 2016. The biological quality elements investigated were benthic macroinvertebrates and benthic algae. The selected quality elements are sensitive to the following pressures: Organic material, eutrophication and acidification. The classification is in accordance with the ‘one out – all out’ principle, which means that the biological quality element with the poorest state determines the total classification of a location. The report provides a thorough description of the methodology and an overview of the results for each quality element. According to the benthic algae, all locations were classified to good or high ecological status based on both acidification and eutrophication. Regarding benthic fauna, one location in river Vinstra was classified to moderate status based on the metric for organic material (ASPT), whereas the remaining two locations were classified to good and high ecological status. In river Sjoa the ecological status based on ASPT declined from 2012/2014 to 2016. Benthic fauna (ASPT) was decisive in an overall assessment of ecological status because this quality element was the most sensitive one.