Small lakes on the border area have partly recovered from acidification as a result of diminished sulfur dioxide emissions. However, effects on communities vulnerable to acidification can be seen clearly. Small lakes have been studied in Norway, Finland and Russia. Norwegian lakes are in Jarfjord, north of the Petchenganikel and downwind the prevailing wind direction. Finnish lakes are located in Vätsäri, east of the Petchenganikel where emissions reach rarely. Russian lakes in Pechenga are in the near vicinity or south of the emission sources.
Environmental effects of the Petchenganikel mining and metallurgical industry can be seen in water quality of small lakes in the border area in a variety of ways. Heavy metals and acidifying fallout are transported into the lakes by air. Prevalent winds from south-southwest drive pollutants mostly to the areas in the north and northeast and to the immediacy of pollutant sources. However, water quality has improved to some extent as a result of decrease pollutants from the industry.
The heavy metal concentrations in the lakes of the whole border area are higher than concentrations in reference lakes. The community is most affected at 10 km radius from the smelter, where nickel and copper concentrations are multifold compared to the rest of the area. Also north from the smelter in the area of Jarfjord some lakes have higher heavy metal concentrations nowadays than in the 1990s. The increase in copper concentrations still continues in the small lakes of all three countries, and nickel concentrations increase in Russia and Norway.
Effects of acidifying sulfur compounds spread out to a wider area than heavy metals. Small lakes are the most sensitive to acid deposition. The most vulnerable lakes can be found in Jarfjord, Sør-Varanger and Vätsäri areas, which have acidic types of rocks. In these areas bedrock usually consists of granite and gneiss, and the soil is often quite thin.
Some of the small lakes are however located in areas where the bedrock and soil are alkaline. This protects the lakes from acidification because their natural buffering capacity is then strong and acidic fallout is neutralized. Another neutralizing factor is emissions of alkaline dust from industry, the clearest effects of which are limited to the vicinity of the emission source in Petchenga.
Some recovery has been noticed in the condition of small lakes at the most vulnerable areas in Jarfjord and Vätsäri. This is most likely a result of decreased sulfur dioxide emissions.
In the studies on water, sediment means the layered earth that has drifted and fallen out to the bottom of a water body.
Sediments are usually formed on the bottoms of seas, lakes and rivers. By analysing sediment layers, information may be obtained on the loading on the waterways and its fluctuations in the long-term. For instance, sediment studies are used to identify changes in the state of waterways, as well as climate trends during different periods.
of small lakes was studied in 1990’s both nationally and internationally. In the lake sediments of Norwegian-Russian border mercury, nickel and lead concentrations were studied at the start of the decade. In Sør-Varanger also the occurrence of persistent organic pollutants was studied.
The top few centimeters of bottom sediments of the Lake Inari - River Pasvik area consist mostly of substances deposited in the last 10-20 years. The deeper sediment layers reflect time before the industrialization of the Kola Peninsula and even before the industrial revolution of Europe. At depths of a few tens of centimeters it is possible to study, for instance, the natural background concentrations of heavy metals.
The most important heavy metals in the area are copper and nickel. Others include cadmium, cobalt, zinc, arsenic, mercury, and lead, for instance.
Research of vertical distribution of heavy metals in the bottom sediments allows the study of historical trends in pollution. The heavy metal concentrations have started to increase somewhat already with the start of the industrialization in Europe in the middle of 17th century as air transport has brought pollutants to the Arctic. The most intensive growth of concentrations is, however, due to start of operations of the Pechenganikel copper-nickel smelter in the 1920’s and 1930’s.
There is a clear relationship between the concentrations of pollutants in sediments and their distance from the smelters, so, it is clear that the pollution of sediments originates from emissions of the industry in the area. Also, the prevalent wind directions have influence on concentrations of pollutants at different distances from the smelter, as they carry pollutants mostly to the north and the northeast from the smelter. The most polluted areas with the highest heavy metal concentrations are the nearest to the smelters and in Jarfjord, Norway, in the prevalent wind direction.
The highest concentrations of nickel, copper, cobalt, cadmium, arsenic and mercury, that are 2-25 times higher than the background concentrations, were measured in lakes less than 50 km away from the smelters. At the distance of 60-100 km the concentrations of metals originating from the smelters decrease but the concentrations of other heavy metals, for example, lead, are still high.
The phytoplankton species composition in the small lakes is diverse. The most abundant algal groups were diatoms, blue-green, green, and yellow-green algae, but the species composition is different in Finnish, Norwegian and Russian small lakes. Differences in the species present in the lakes are mainly due to different hydrochemical conditions. Phytoplankton species diversity was highest in Russian lakes, which are also most nutrient-rich, and lowest in Jarfjord. The Jarfjord lakes are the most polluted with heavy metals and sulphates, and it seems that the Pechenganikel copper-nickel-smelter has an impact on phytoplankton community.
Benthic diatoms attached to substrate are studied to monitor water quality and changes in it. Diatoms react fast to changes in nutrient concentrations and acidity of their habitat, and their growth is also influenced by heavy metal concentrations. Species diversity was the highest in Vätsäri lakes and the species detected there are regarded as sensitive to pollution. The lowest diversity was in Jarfjord which is probably mainly due to high heavy metal concentrations and earlier quite severe acidification.
Changes in the abundance, species diversity and community composition of benthos reflect changes in the environment. Benthos of the small lakes is sensitive to acidification of water. As the condition of the lakes near industrial areas has gradually recovered, the state of benthos has also improved in its entirety. However, condition of the benthos in those areas is still worse than in the less loaded lakes further away.
On the other hand, the benthos community seems to have regressed in the further-away lakes with better conditions. Even though the water quality has improved in the border area lakes and the number of specimen of species vulnerable to acidification have increased, the total amount of species has significantly decreased. Causes for this are unknown, but they can be natural or anthropogenic.
The total number of species in the littoral zone of the lakes is the same in the Finnish Vätsäri and the Russian lakes (36 and 34 species, respectively) on average, but the number of species is much lower in Jarfjord, Norway (24 species). Also the number of species that belong to the
EPT-group is formed of zoobenthos that is sensitive to environmental changes: mayflies (Ephemeroptera), stoneflies (Plecoptera) and caddisflies (Trichoptera).
They are regarded as indicator groups, because their presence or absence in a water body indicates the status. If there is an abundance of sensitive species, the status is good.
of mayflies (Ephemeroptera), stoneflies (Plecoptera) and caddisflies (Trichoptera) are smaller in Jarfjord. The cause of this is probably the higher sulfate and heavy metal concentrations in Jarfjord, but also the more northern location and smaller catchments can have an effect. The numbers of benthic animals in the profundal zones are small in all the studied lakes.
In a few lakes on the Finnish side of the border there has been a growth of aluminum levels in the tissues of caddisfly (Trichoptera) larvae in comparison to the levels of early 1990’s. However, these results were based on a small sample size, and thus further studies are needed for more reliable results.
Environmental effects caused by mining and metallurgical industry are the most significant in the lakes and ponds in the vicinity of the industrial region. There, for example, heavy metals accumulate in the organs of fish. Fish communities are also affected by persistent organic pollutants which accumulate in the adipose tissues of animals and are enriched on the higher levels of food chain. Also, acidification caused by sulfur dioxide fallout has caused problems in some places.
The original fish community of small northern latitude lakes consists mainly of salmonids and whitefish morphs that thrive in cold water, for example, in the Jarfjord lakes in Norway the main species are trout and char. As the water temperature rises due to climate change, these species decrease and the proportions of perch, pike and cyprinids, which thrive in warmer water, increase. These kinds of changes in species composition, which can happen even on a short time scale and are promoted by pollution load, have already been observed in the Russian study lakes.
Heavy metal exposure causes deformations in fish. In the Russian small lakes especially whitefish, perch and char have been studied and deformation in liver, kidneys, gonads and gills have been observed. Most commonly detected are damaged liver, increase of connective tissue in kidneys and gonads, segmented gonads, asynchronous maturation of reproductive products and distortions in whitefish gill rakes.
In the Russian small lakes the most important heavy metals are copper, nickel and mercury. Copper accumulates mainly in the fish liver and kidneys, and copper concentrations have either risen or stayed the same. Nickel accumulates mainly in the kidneys and gills, and the concentrations have decreased a little. Mercury accumulates mainly in liver and kidneys, and the concentrations are the highest in predatory fishes. However, mercury concentrations that are higher than the maximum allowable concentration have been detected in the muscle tissues of perch and pike.
In the small lakes located in the area between Nikel and Zapoljarny nickel and copper concentrations are the highest, and fish community has been completely destroyed in many of these lakes. Only 20 % of nickel emissions are spread by air. Nickel concentrations decrease further away from the smelters. Nickel concentrations in whitefish kidneys are at the same level in the small lakes as in the Pasvik River upstream of the emission sources. The levels of copper concentrations do not change in a similar way, which may be caused by natural variations in copper concentrations of the area.
The effects of acidification can be seen in the fish communities of a few very small lakes about 10–40 km from the smelters, especially in the areas where natural buffering capacity of bedrock and soil is weak. For example, it the Jarfjord area in Norway populations of lake brown trout and Arctic char have suffered from acidification. Also, in Vätsäri area in Finland at least minnows, which are very vulnerable for acidification, have disappeared from some lakes smaller than five hectares. Acidification is still a threat to fish communities of smaller and more vulnerable lakes, even though their buffering capacity has recovered due to decrease of pollution according to studies in the last ten years. In the vicinity of the smelters the alkaline dust emissions of industry increase buffering capacity of the lakes, which means that in about 10 km radius from the smelters there are no acidified waters.
The newest report covering the state of the small lakes of the border area is the ‘Pasvik Water Quality Report until 2013’, which contains the water quality monitoring results of 2000–2013. Information about the state of the sediments and the biological state can be found in the report Environmental Challenges in the Joint Border Area of Norway, Finland and Russia.