Sammendrag
NIVA has undertaken targeted monitoring of the Ranfjord in 2018 on behalf of Mo Industripark AS,
Celsa Armeringsstål AS, Elkem Rana AS, Ferroglobe Mangan Norway, Rana Gruber AS, Miljøteknikk
Terrateam AS and Rana municipality. The monitoring program has been prepared in accordance with
the Water Frame Directive and approved by the Norwegian Environment Agency. The program is
designed on the basis of the companies' emission components to the Ranfjord. The following
substances have been analysed: metals (mercury, lead, arsenic, cadmium, chromium, copper, nickel
and zinc), polycyclic aromatic hydrocarbons, polychlorinated biphenyls, perfluorinated
alkylsubstances and tributyltin. These substances were analysed in blue mussel from three stations
and in sediment samples from four stations. Analyzes of the flotation chemical Lilaflot D817M was
also done for 10 sediments. In order to document ecological status, the bottom fauna of 10 stations
was examined.
Ecological status
In general, the entire Ranfjorden was species poor. The number of individuals was high, though at
the two outermost stations the number was lower and within the normal. The two outermost
stations (16R and 20R) achieved "good" ecological status. Furthermore, station RE04 was classified to
"good" ecological status, though it was very close to "moderate". The other stations were classified
to "moderate" ecological status. The fauna composition showed a large proportion of tolerant
species, and in particular species that tolerate a high degree of slurry. The sediment was very finegrained
and there was low content of nutrients throughout the fjord. Combined with observations of
tailings in the sediments out to and including station RN9, it is concluded that it is primarily mining
waste that adversely affects the soft bottom fauna.
Chemical status
Two of the sediment stations are classified as having "not good" chemical status due to exceedance
of the lEnvironmental quality standard (EQS) for priority substances. EQS were exceeded for the PAH
compounds anthracene, benzo (b,j)fluoranthene, benzo(g,h,i)perylene and indeno(1,2,3-cd)pyrene.
There were no exceedances of EQS for priority substances in the blue mussels in this study. The
chemical status of the three mussel stations is therefore classified as "good".
PCBs were not detected in any of the sediment samples, but the blue mussels collected at
Toraneskaia and Moholmen exceeded the EQS for PCB7. No perfluorinated alkyl substances (PFAS)
were detected in the sediment samples or in the blue mussel samples. The flotation chemical Lilaflot
D817M was detected in sediment samples, but in lower concentrations than in 2016.
For several years the discharges of PAH compounds to the Ranfjord have been reduced. This is
confirmed by lower concentrations of PAHs in blue mussels the last few years. Significant downward
trends were found for PAH componds in blue mussels for the three monitoring stations in the inner
Ranfjord. There were also significant downward trends for concentrations of heavy metals in blue
mussel. The concentration of lead had however increased in blue mussels north of Toraneskaia.
There were lower concentrations of PAH compounds and heavy metals in the sediment in 2018 than
in the previous years.
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