Operational monitoring in Holmestrandsfjorden for NOAH Langøya

Summary

Concentrations of contaminants in blue mussels (Mytilus edulis), contaminants and the environmental condition in sediments, littoral zone communities, eelgrass (Zostera marina) distribution and condition and nutrients, chlorophyll a, secchi depth, oxygen concentration, radionuclides, temperature and salinity in seawater were investigated by NIVA in 2015. The investigation is part of a monitoring programme in the marine recipient in the vicinity of a plant receiving industrial waste on the island of Langøya in the Oslofjord. The plant is owned by NOAH AS. A brief inspection of the area was performed by NIVA in 1994, and monitoring has been done annually since 1996. Results from the investigations performed in 2015 are presented in this report.