Generally low levels of hazardous chemicals
Many hazardous chemicals can be transported long distances by ocean or air currents. Generally, there are low levels of hazardous chemicals in Norwegian waters, along the coast and lakes, but in some lakes and fjords, high levels do occur.
Higher chemical levels found in aquatic species
We will often find higher levels of hazardous chemicals in aquatic species, compared to species that live on land. There are many reasons for this:
- Hazardous chemicals released from various sources mostly end up in the aquatic environment, where the food chain is more extensive than on land.
- The accumulation of hazardous chemicals through the food chain in water results in considerable concentrations in animals high up in the food chain. This applies to species such as the polar bear, trout and certain birds.
- Aquatic species often have substantial fat layers where chemicals are stored. The most dangerous chemicals, such as PCBs, dioxins and mercury can cause damage even in low concentrations.
Both local and international sources
The hazardous chemicals that end up in water come from many different sources. In some areas, earlier local discharges from industry and agriculture have resulted in high levels of hazardous chemicals in fish and other aquatic species. This is the case in areas such as Sørfjorden in Hardanger and in Lake Mjøsa. In addition, seepage from landfills, effluent from waste water treatment plants and the dispersal of polluted sediments add to the problem.
Hazardous chemicals transported far by ocean and air currents
Long-range air pollution is a major source of hazardous chemicals in Norwegian water bodies. Air currents move north from central parts of Europe and Asia, carrying hazardous chemicals that fall over Norway and other Arctic areas. The high levels of mercury found in Norwegian fresh water fish are mainly caused by long-range transport by air currents.
Local remediation and international co-operation
The Climate and Pollution Agency has mapped over a hundred locations of polluted marine sediments along the Norwegian coast. Of these, 17 locations have been identified as particularly exposed, of which seven are harbour areas. In several of these areas, pilot projects have been initiated to try out various forms of measures.
On the basis of monitoring of the environmental state, measures are carried out to prevent the consumption and marketing of contaminated seafood.
International cooperation
Norway is a contracting party to the OSPAR convention for the protection of the marine environment of the North-East Atlantic. The Norwegian government is actively working towards the ambitious target to halt inputs of hazardous substances by the year 2020.