Valkova S.A. Selected aspects of the current state of freshwater resources in the Murmansk Region, Russia. Journal of Environmental Science and Health, Part A. 2017, V. 52, No 9, p. 921-929.

Downloaded by [Professor Vladimir Dauvalter] at 05:55 30 August 2017 926 N. A. KASHULIN ET AL. The smelt from Lake Onega was introduced into Upper Tuloma reservoir in the form of larvae during the period from 1979 to 1985. Then, the species spread into bodies of water in the Kola and Niva river basins. The smelt has received a wide­ spread occurrence in Lake Imandra during the last decades. It has almost fully replaced vendace and is reducing the reproduc­ tion efficiency of other fish species by destroying young fish and creating harsher competition for food. The spawning strategy of the smelt, which spawns in rivers, turned out to be more effi­ cient than that of native species spawning in spring (pike, perch, ide). After a winter-spring decrease of storage by the Niva HEPs, the fish almost loses its spawning sites in the lake. Such factors as short life-cycle, absence of predation pressure, small-scale fishing catches, and successful reproduction make smelt the dominant species of the Lake Imandra. The number of ruffe, Gymnocephalus cernuus, is also rapidly growing. In some parts of the lake (northern regions of Big Imandra), these two species completely dominate the ichthyofaunal structure. Reproduction of other fish species is inefficient, and their repopulation takes place mostly due to migration from second­ ary lake-river systems (semi-diadromous forms of whitefish, trout). Similar changes in the structure of fish populations are typi­ cal for other bodies of water in the Niva River basin (Permuso- zero Lake) and Kola River basin (Kolozero, Kakhozero lakes), which are considered as salmon-whitefish waters. Ruffe Gymnocephalus cernuus, European smelt Osmerus eperlanus and vendace Coregonus albula are low-value and dominant species. The structure of the fish population in the above-men­ tioned water bodies is surely influenced by anthropogenic fac­ tors, which are typical for central industrial part of the Murmansk region, including uncontrolled fishing (mostly of salmon and whitefish) and a decrease in fish reproduction effi­ ciency. Another example of substantial changes in the structure of fish populations is in the water bodies of the Ponoi River basin (central part of the Kola Peninsula). There has been a sharp increase in the numbers of roach and ide in recent years. The ide were widespread only in the upstream portion of the Ponoi River basin in front of the Lake Woodjavr.[14,15] Cur­ rently, ide inhabits both upstream and downstream sections of the river. Thus, although pollution of surface waters of the Murmansk region has been occurring for several decades, it should be stated that deep structure-function changes of freshwater eco­ systems are proceeding now. In the previous century, intensive industrial pollution of water basically affected fish at the organism and population levels, but a rapid change in the struc­ ture of fish community is now under way. A dramatic deterio­ ration in the quality of subarctic water bodies related to multi­ factorial industrial pollution and intensified eutrophication of water bodies under conditions of regional climate change results in the development of phenomena that are not typical of the Far North. The typical oligotrophic water bodies of the Subarctic are undergoing serious changes, which testify to rapid transformations of their trophic status at the background of sta­ ble or elevating level of sub-lethal water toxicity. This can seri­ ously damage many sectors of the economy and affect the development conditions in the region. Generally, the decrease in resource potential of surface waters is taking place in the region. At the same time, an increase in the trophic status of lakes caused by eutrophication can increase their fish produc­ tivity. However, it requires scientifically based management of water resources. Assessment of environmental pollution risks for human health is an important aspect of the study of pollu­ tion. The main outcomes of climate change and environmental pollution on water systems are shown in Figure 3. New approaches to the assessment o f water quality and the state o f water resources The function of water ecosystems under new conditions requires a review of methodological approaches to the assess­ ment of water quality and the state of water resources and the establishment of a hydro-environmental monitoring system in the region. First, there must be indicators of surface water qual­ ity. It is necessary to develop the list of the water quality indica­ tors that account for regional peculiarities. As an example, we can suggest water quality indicators based on analysis of refer­ ence concentrations of a range of substances in surface waters and sediments. For establishing water pollution criteria for freshwater bod­ ies of the Murmansk region, we suggest the determination of heavy metal concentrations in reference and relatively pollu­ tion-free water bodies located at distances of more than 40-50 km from main sources of industrial pollution (mining and metallurgical enterprises). The works of researchers from INEP, for example,[16-18] indicate that at distances of 40-50 km from industrial plants there are practically no effect of these contaminants on the chemical composition of water and sedi­ ments. Reference concentrations in water (Fni) for each element were determined as median values (M) plus standard deviation (sn) of heavy metal concentrations in 400 lakes in the western Table 1. Median (M), average (X), minimum (min) and maximum (max) concentrations of elements (mg/l), standard deviations (Sn) and reference unpolluted values (Fni) in waters of 400 lakes of the western part of the Murmansk region and suggested water pollution criteria for heavy metals in freshwater bodies of the Murmansk region. b.d.l. - below detection limit. Element Lake water of the Murmansk region Pollution load M X Min Max sn M + s n Fni Background Moderate Marked Strong Cu 0.70 1.37 b.d.l. 22.0 2.5 3.19 3.0 <3 3-15 15-30 >30 Ni 0.6 1.0 b.d.l. 9.0 1.2 1.77 2.0 <2 2-10 10-20 >20 Zn 1.7 2.6 b.d.l. 24.0 3.1 4.82 5.0 <5 5-25 25-50 >50 Co 0.2 0.3 b.d.l. 8.0 0.8 1.00 1.0 <1 1-5 5-10 >10 Cd 0.05 0.10 b.d.l. 0.99 0.16 0.21 0.20 < 0.2 0.2-1 1-2 >2 Pb 0.30 0.34 b.d.l. 1.4 0.24 0.54 0.50 < 0.5 0.5-2.5 2.5-5 >5 As 0.010 0.070 0.01 0.25 0.096 0.106 0.100 < 0.1 0.1-0.5 0.5-1 >1