Climate change may have consequences for the pollution situation in the Barents Sea. The routes and mechanisms by which persistent organic pollutants, heavy metals and radionucleides are delivered to the area are strongly influenced by climate variability and global climate change. Increased precipitation could cause faster washing out of hazardous substances that are currently combined in the environment.
Increased sea temperature may indirectly influence the ecosystem through change in supply, turnover and effects of nutrient salts and hazardous substances. Change in wind patterns and sea currents may affect the transport of both local and long-range transboundary pollution. This can in turn enhance the already negative effects of hazardous substances. Melting of sea ice may release polluting substances trapped in the ice, but the knowledge about this is limited. More knowledge is needed about the combined effects of pollution, climate change, acidification and other impacts.
The role that climate change may play with regard to increased risk of radioactive pollution in the region is a developing issue. Changes in permafrost, precipitation and extreme weather events may affect infrastructure related to nuclear activities and will require new assessments. For example, the impact of weather and climate on infrastructure is well known for Andreeva Bay where freeze-thaw actions contributed to loss of integrity of the fuel storage facility and extensive contamination of Andreev Bay site. Further degradation combined with precipitation has contributed to radioactive material being washed out into the marine environment (AMAP, 2009). Changes in ocean circulation and in the sea ice may affect the pathways of radioactive substances in the marine environment. It is expected that movement both into an out of the Barents Sea may become more rapid than today (AMAP, 2009). Climate change could also influence the transport of radionuclides from Mayak to the Arctic areas.
There is also a new potential risk of radionuclides’ remobilization from localised areas with contaminated sediments, their re-suspension and transfer to the surrounding areas. In connection with the Barents Sea, it could be suggested to carry out additional monitoring in Chernaya Bay area (a fjord on the southwestern coast of Novaya Zemlya with high levels of radioactivity in sediments after nuclear tests during the Cold War). As known, the levels of 239,240Pu in sediments from Chernaya Bay are among the highest ever reported for the marine environment and previous investigations indicated that the natural transport of contaminated sediments from Chernaya Bay has resulted in increased 239,240Pu levels in the south-eastern part of the Barents Sea. In addition, elevated levels of radioactive plutonium measured in benthic biota indicate that significant uptake has occurred in the food chain (Smith et al., 1999; Carroll, 2002; Matishov, 2004). This could also represent a potential radiological threat to the local commercial fishery. Consequently there is a need to assess current status and potential environmental risk as well as to conduct more research to understand how the climate change will affect the inflow of new sediments and re-suspension and transfer of contaminated sediments to surrounding areas and potential long-term effects.
Changes in temperature may also lead to changes in turnover rates of radionuclides in cold-blooded animals such as fish. More research is needed to study relationships between diverse climatic, physicochemical and biotic factors that influence the uptake and bioaccumulation of radionuclides by marine species and to assess their combined effects.