Monitoring of coastal waters in the Hardanger River Basin, 2017

Summary

DIHVA IKS designed a monitoring program for coastal water in the Hardanger river basin for 2017-2021, on behalf of the companies Boliden Odda AS and Tizir Titanium & Iron AS. The program was approved by the Norwegian Environment Agency in a letter of 22.12.2016. The program for 2017 was carried out by NIVA, in collaboration with Hardanger Miljøsenter. In this program (2017-2021), measurements of the following quality elements should be carried out at certain stations in the water bodies Sørfjorden inner part (ID 0260040900-1-C), Sørfjorden outer part (ID 0260040900-2-C) and Samlafjorden (ID 0260040800-C): In the water column: Secchi depth, temperature, salinity, oxygen, metals and fluoride. On the sea bottom: Benthic fauna and sediments habitat characteristics, metals and PAHs in sediment. In biota: Metals in fish (tusk), metals and PAHs in mussels. In 2017, the program comprised stations in the water bodies Sørfjorden inner part (ID 0260040900-1-C) and Sørfjorden outer part (ID 0260040900-2-C), as well as the following quality elements: In the water column: Secchi depth, temperature, salinity, oxygen, metals and fluoride. In biota: Metals and PAHs in mussels. Biological quality elements were not evaluated in 2017. The results showed the following: Ecological status was not classified as there were no data on biological quality elements. With regard to the physico-chemical support elements, oxygen at the deepest probe depth (here regarded as bottom water) showed very good condition (with the reservation that lower oxygen concentrations may exist even closer to the bottom) at Sø7/2 and Lind1 stations. The secchi depth at these stations corresponded to moderate condition. (...)