Oil and gas
Discharges and emissions from oil and gas activities mainly influence the levels of hydrocarbons, some heavy metals and radioactive substances in nearby water, sediment or biota and emission of greenhouse gasses to air (emmission and discharges are given in chapter Emission, operational and accidental discharges). Oil and gas activity in the Barents Sea has so far been limited. However oil and gas fields have been discovered in both the Russian and Norwegian part of the Barents Sea and both countries have plans for increased activities on their continental shelfs in the years to come (see Seismic surveys).
Unexploited oil and gas reservoirs may also influence the ecosystem due to natural seepages of hydrocarbones. Some faults dissect the entire sediment level and are fixed at the bottom of the sea as relatively small siphons (up to 1 m in width and a few meters deep). These siphons are sources of local and temporary anomalies in the levels of heavy metals and hydrocarbons. They have been observed during the monitoring efforts near the Shtokman and Fedynsky fields as well as in the bottom waters and bottom sediments.
Maritime transport and fisheries
Maritime transport and fishing vessels may influence the environment negatively through operational discharges to sea and air, illegal discharges, waste (marine litter), introduction of alien species via ballast water and hulls and noise (see chapter Oil and gas activities).
Ships contribute to emission of substances like CO2, NOx, SOx and PAH to the air and discharges of oil containing waste water to the sea. The knowledge about the exact size of the illegal discharges from ships to water in the area is limited.
Marine litter is found throughout the marine environment (seabed, water column and coastlines) and poses a risk to marine animals trough ingestion and entanglement. The main sources of marine litter are fishing (including abandoned and lost fishing gear), shipping and tourism. The extent of the problem in the Barents Sea area is unknown. Status for marine litter is given in chapter Current status and trends for hydrocarbons.
There are several local sources of radioactive substances in the Barents Sea area which poses a potential threat to the marine environment. Among these are radioactive waste containers dumped in the Barents and Kara Seas by the former Soviet Union (FSU) and sunken submarines such as the Komsomolets in the Norwegian Sea and the K-159 in the Barents Sea (NRPA, 2006a; 2007b). Underwater and surface nuclear tests on Novaya Zemlya between 1955 and 1962 have resulted in local areas with high levels of radionuclides in the sediments.
Industrial activities, such as mining and oil production may change the distribution of naturally occurring radionuclides in the marine environment. From offshore oil production some volumes of produced water containing dissolved 226Ra and 228Ra can be discharged into the sea, but this will be small volumes because of the zero discharge requirements in the Barents Sea. Additionally, the possible use of Floating Nuclear Power Plants (FNPP) in oil and gas extraction in the Russian Arctic would increase the potential risk of radioactive pollution in the region (see also chapter Risk related to radioactivity). The primary groups of concern from a pollution point of view are the fission products (e.g. Cs, Sr isotopes) and transuranics (e.g. Pu, Np isotopes). Aside from risks associated with FNPP’s themselves, there is further potential for pollution arising from supporting shore based facilities designed for the purpose of refueling, waste handling, decommissioning and other activities (NRPA, 2008c). Other sources of radioactive substances are mentioned under the relevant subtitles further in this chapter.
Transport of contaminants into the Barents Sea
The main sources of contaminants in the Barents Sea are those from outside the area and that are transported into the area.
Selected anthropogenic pollutants, including POPs, trace metals and radionuclides are transported via different pathways (mostly a combination of atmosphere, ocean currents, ice drift and rivers) into the Arctic and the Barents Sea (see Figure 2.5.9) Contaminants can later be redistributed within the region by a combination of the same transport pathways.
Atmospheric transport is the most rapid route for POPs (e.g PCBs, brominated flame retardants (BFR), PFC and heavy metals, incl. e.g mercury (Hg). Under favourable meteorological conditions, rapid air transport of contaminants can take place in a few days or weeks from the source region (e.g Europe, North America and Asia) into the Arctic (AMAP 2004). Contaminants are transported as gases, aerosols or they are absorbed by particles in the air, depending on the properties (vapour pressure, solubility etc.) of the contaminants.
Riverine inputs from larger rivers may be an important source of contaminants to the area. Particles transported to the coast by large Russian Arctic rivers like Yenisei and Ob during the melting period are contaminated with pollutants originating from industrial areas. As a result of various physical processes, particles, that may contain large amounts of contaminants, are incorporated in costal ice in the Kara Sea. These ice-bound particles may be transported into the Barents Sea and released in the main ice melting areas east of Svalbard (AMAP 2004).
The transport via sea currents is a slow process and may take years, but may be important for transporting contaminants. Ocean currents, particularly the Norwegian coastal current, transport contaminants into the Barents Sea. This is especially noticeable for radioactive contaminants (137Cs, 239+240Pu, 241Am and 99Tc) resulting from discharges from European nuclear reprocessing facilities in the Irish Sea and English Channel. Fallout from the Chernobyl Accident (1986) in outflowing Baltic water is also transported by ocean currents to the Barents Sea (e.g. Aure et al., 1998; NRPA, 2007; Matishov, 2001). Fallout from atmospheric nuclear weapons tests (1950-1980) and the Chernobyl accident can still be found in the Arctic marine environment.
Secondary sources of pollution
Secondary contamination is the release of pollution, which already is in the environment as a result of previous emission. This is e.g. fallout of aerosol particles from ice and snow into the sea water, input of chemical components from the bottom sediments as a result of geochemical processes in the “sea bottom-water” border region and formation of new chemical compounds within the water column from simpler components. Contamination due to water exchange in the river mouth where the industrial areas/human settlements are upstream can also be considered as secondary.
Pollution from onshore and near-shore sources
There are relatively few large sources of on-shore or near sources to pollution in the Norwegian part of the Barents Sea. There are however several small-scale discharges from many different sources such as landfills, fish farms, contaminated sites and small enterprises which may have the overall effect of raising pollution levels in near-shore waters. In many harbours where there are or have been shipyards or boat-builders’ yards, the sediments are polluted by tributyl tin (TBT) and tar. PCBs have also been found in some areas.
In some coastal areas in the Russian part of the Barents Sea area, local sources of pollution are considered to be considerable. An example is the municipal and industrial waste water in Murmansk which is discharged practically without any treatment into the sea. The coastal areas, and particularly the bottom sediments, are therefore not just contaminated, but have locally altered the physical properties, and also represent a source of secondary pollution to the environment.
The multiple Russian naval bases with nuclear submarines are a major source of environmental pollution. This includes leakage of radioactive substances from radioactive wastes stored in shore facilities (e.g. from Andreev bay), the use of support vessels to store radioactive waste (e.g. the Lepse), diesel and waste water discharge, pollution from special painting used on the ships and waste water from the communities connected to the naval bases. In the areas of tactical exercises there is a large amount of metal and, at times, highly toxic liquids that end up on the sea bottom. There is also a huge impact on the ecosystem from semi destroyed and sunken ships that often contain large amounts of fuel.