Nordre Fosen Region – marine investigations of environmental status in selected water bodies 2014-16

Summary

Investigations have been carried out in five selected water bodies to find the environmental status. The investigated locations are Vågen at Storefosna, Herfjorden, Osen, Kuringvågen and Setervågen. The ecological status has been examined by use of the biological quality elements phytoplankton and benthic microalgae, and in addition analysis of river basin specific substances in sediments and blue mussel. The chemical status has been defined by analysis of EUs priority pollutants. However, the examination program at each station has been different. At Vågen both the biological quality elements and river basin specific substances have been investigated. High values of 90th percentile of chlorophyll a resulting in “Moderate” ecological status. Analysis of the EUs priority pollutants showed higher values in the sediments than the EQS-value (EQS = Ecological Quality Standard) giving “Not good” chemical status. In Herfjorden the ecological status has been found by use of the biological quality element phytoplankton and analysis of river basin specific substances in sediments and blue mussels. Concentrations of river basin specific substances higher than the EQS-value resulted in “Moderate” ecological status. The chemical status was “Not good” caused by concentrations of EU priority pollutants higher than EQS-value. Based on use of the biological quality elements phytoplankton and benthic macroalgae the ecological status in Osen was “Good”. The sampling program in Kuringvågen and Setervågen was too short to carry out a classification.