Pasvik River Research Articles

Exploiting the “white coal” of the Pasvik River. Negotiating corporate and national interests in the border region during the German occupation of Norway

ABSTRACT The history of the Pasvik River, demarcating Norway’s border with Russia in the north is inextricably linked with issues of security and national interests on the one side, and exploitation of natural resources and business interests on the other. This applies not least to the war years, as German warfare in Europe increased the value of the hydropower and the strategic metals of the border region. Drawing on sources from the archives of the mining company AS Sydvaranger and Norwegian state administration, this article traces the negotiations on hydropower exploitation in the Pasvik River throughout the Second World War focusing on Norwegian key actors, and analyses Norwegian national and corporative interests and strategies in the border area during the German dominance in the region.

First report on pollutant accumulation and associated microbial communities in the freshwater sponge Spongilla lacustris (Linnaeus, 1759) from the sub-Arctic Pasvik River (Norway).

This explorative study was aimed at first characterizing the sponge Spongilla lacustris (Linnaeus, 1759) from the sub-Arctic Pasvik River (Northern Fennoscandia), in terms of associated microbial communities and pollutant accumulation. Persistent organic pollutants were determined in sponge mesohyl tissues, along with the estimation of the microbial enzymatic activity rates, prokaryotic abundance and morphometric traits, and the analysis of the taxonomic bacterial diversity by next-generation sequencing techniques. The main bacterial groups associated with S. lacustris were Alphaproteobacteria and Gammaproteobacteria, followed by Chloroflexi and Acidobacteria. The structure of the S. lacustris-associated bacterial communities was in sharp contrast to those of the bacterioplankton, being statistically close to those found in sediments. Dieldrin was measured at higher concentrations in the sponge tissues (3.1 ± 0.4ng/g) compared to sediment of the same site (0.04 ± 0.03 ng/g). Some taxonomic groups were possibly related to the occurrence of certain contaminants, as was the case of Patescibacteria and dieldrin. Obtained results substantially contribute to the still scarce knowledge of bacterial community diversity, activities, and ecology in freshwater sponges. PRACTITIONER POINTS: Microbial community associated with Spongilla lacustris is probably shaped by the occurrence of certain contaminants, mainly dieldrin and heavy metals. A higher accumulation of dieldrin in the sponge mesohyl tissues than in sediment was determined. S. lacustris is suggested as sponge species to be used as a sentinel of pesticide pollution in the Pasvik River. S. lacustris, living in tight contact with soft substrates, harbored communities more similar to sediment than water communities.

Foraging morphology and diet divergence of European whitefish (Coregonus lavaretus) in water courses of Murmansk region

European whitefish (Coregonus lavaretus) is a highly polymorphic species. In general, it is assumed that the divergence in whitefish is a form of a specialization in the use of the resources (including food) of the main limnological zones – pelagic (plankton), littoral (benthos, plankton), profundal (benthos) – and the morphological adaptations of the shape of the body and head simultaneously determine the direction of the process. The shape and number of gill rakers, which are responsible in whitefish for prey retention, are considered the most important adaptive trait and are most often used to distinguish between its sympatric morphs or ecotypes. Current study will be devoted to foraging morphology and diet divergence of whitefish in water courses of Murmansk region. Our study of the water bodies in three major river basins of Murmansk region revealed the presence of two whitefish morphs: sparsely rakered (further sr) and medium rakered (mr). The mr morph is less common and observed only alongside the sr whitefish. In general, in sr whitefish the number of gill rakers ranges between 15 and 31, and in mr whitefish between 27 and 44. Among whitefishes with 27–31 gill rakers, both sr and mr morphs were observed and distinguishable by the shape of the rakers. In the studied sr whitefish populations, relatively long and short rakered whitefish morphs were found. In Lake Kuetsjärvi (Pasvik River basin), the sr and mr whitefish formed additional slow- and fast-growing ecological morphs. In the water bodies of the Murmansk region, the greatest diversity of sympatric morphs of whitefish (from two – sr and dr to four morphs – sr1, sr2, mr1, mr2) is observed in the most polluted water bodies with higher productivity and a large abundance of such generalists as perch and European smelt. The diet of sr and mr whitefish morphs in the studied water bodies of Murmansk region in summer-autumn period is associated with hydrobiological features of fish habitats. Sr whitefish morph from the Pasvik, Tuloma and Niva Rivers basins, inhabiting mainly littoral and profundal areas of water bodies, have a benthic diet. Mr whitefish morph, inhabiting mainly littoral and pelagic areas of water bodies, have both benthic and mixed feeding types. According to our data, coexistence of four morphs of whitefish in Lake Kuetsjärvi (lower Pasvik River) – sr1, mr1, sr2 and mr2 have the low specialization and use the most abundant recourses in lake. The most extensive overlapping of feeding spectra is found in small morphs in Lake Kuetsjärvi – sr1 and mr1. On the basis of our data on whitefish from water bodies of Murmansk region we found active gill apparatus functioning in fish, as minimum length of food organisms in sr and mr whitefish morphs were sometimes less than or equal to gill rakers distances of fish.

Benthic Microbial Communities in a Seasonally Ice-Covered Sub-Arctic River (Pasvik River, Norway) Are Shaped by Site-Specific Environmental Conditions.

The Pasvik River experiences chemical, physical, and biological stressors due to the direct discharges of domestic sewage from settlements located within the catchment and runoff from smelter and mine wastes. Sediments, as a natural repository of organic matter and associated contaminants, are of global concern for the possible release of pollutants in the water column, with detrimental effects on aquatic organisms. The present study was aimed at characterizing the riverine benthic microbial community and evaluating its ecological role in relation to the contamination level. Sediments were sampled along the river during two contrasting environmental periods (i.e., beginning and ongoing phases of ice melting). Microbial enzymatic activities, cell abundance, and morphological traits were evaluated, along with the phylogenetic community composition. Amplified 16S rRNA genes from bacteria were sequenced using a next-generation approach. Sediments were also analyzed for a variety of chemical features, namely particulate material characteristics and concentration of polychlorobiphenyls, polycyclic aromatic hydrocarbons, and pesticides. Riverine and brackish sites did not affect the microbial community in terms of main phylogenetic diversity (at phylum level), morphometry, enzymatic activities, and abundance. Instead, bacterial diversity in the river sediments appeared to be influenced by the micro-niche conditions, with differences in the relative abundance of selected taxa. In particular, our results highlighted the occurrence of bacterial taxa directly involved in the C, Fe, and N cycles, as well as in the degradation of organic pollutants and toxic compounds.

Temporal analysis shows relaxed genetic erosion following improved stocking practices in a subarctic transnational brown trout population

Maintaining standing genetic variation is a challenge in human-dominated landscapes. We used genetic (i.e., 16 short tandem repeats) and morphological (i.e., length and weight) measurements of 593 contemporary and historical brown trout (Salmo trutta) samples to study fine-scale and short-term impacts of different management practices. These had changed from traditional breeding practices, using the same broodstock for several years, to modern breeding practices, including annual broodstock replacement, in the transnational subarctic Pasvik River. Using population genetic structure analyses (i.e., Bayesian assignment tests, DAPCs, and PCAs), four historical genetic clusters (E2001A-D), likely representing family lineages resulting from different crosses, were found in zone E. These groups were characterized by consistently lower genetic diversity, higher within-group relatedness, lower effective population size, and significantly smaller body size than contemporary stocked (E2001E) and wild fish (E2001F). However, even current breeding practices are insufficient to prevent genetic diversity loss and morphological changes as demonstrated by on average smaller body sizes and recent genetic bottleneck signatures in the modern breeding stock compared to wild fish. Conservation management must evaluate breeding protocols for stocking programs and assess if these can preserve remaining natural genetic diversity and morphology in brown trout for long-term preservation of freshwater fauna.

Ice Melt-Induced Variations of Structural and Functional Traits of the Aquatic Microbial Community along an Arctic River (Pasvik River, Norway)

The effects of climate change-induced ice melting on the microbial communities in different glacial-fed aquatic systems have been reported, but seasonal dynamics remain poorly investigated. In this study, the structural and functional traits of the aquatic microbial community were assessed along with the hydrological and biogeochemical variation patterns of the Arctic Pasvik River under riverine and brackish conditions at the beginning (May = Ice-melt (−)) and during the ice-melting season (July = Ice-melt (+)). The microbial abundance and morphometric analysis showed a spatial diversification between the riverine and brackish stations. Results highlighted different levels of microbial respiration and activities with different carbon and phosphorous utilization pathways, thus suggesting an active biogeochemical cycling along the river especially at the beginning of the ice-melting period. At Ice-melt (−), Gammaproteobacteria and Alphaproteobacteria were dominant in riverine and brackish stations, respectively. Conversely, at Ice-melt (+), the microbial community composition was more homogeneously distributed along the river (Gammaproteobacteria > Alphaproteobacteria > Bacteroidetes). Our findings provide evidence on how riverine microbial communities adapt and respond to seasonal ice melting in glacial-fed aquatic ecosystems.

Bacterial Diversity in a Dynamic and Extreme Sub-Arctic Watercourse (Pasvik River, Norwegian Arctic)

Microbial communities promptly respond to the environmental perturbations, especially in the Arctic and sub-Arctic systems that are highly impacted by climate change, and fluctuations in the diversity level of microbial assemblages could give insights on their expected response. 16S rRNA gene amplicon sequencing was applied to describe the bacterial community composition in water and sediment through the sub-Arctic Pasvik River. Our results showed that river water and sediment harbored distinct communities in terms of diversity and composition at genus level. The distribution of the bacterial communities was mainly affected by both salinity and temperature in sediment samples, and by oxygen in water samples. Glacial meltwaters and runoff waters from melting ice probably influenced the composition of the bacterial community at upper and middle river sites. Interestingly, marine-derived bacteria consistently accounted for a small proportion of the total sequences and were also more prominent in the inner part of the river. Results evidenced that particular conditions occurring at sampling sites (such as algal blooms, heavy metal contamination and anaerobiosis) may select species at local scale from a shared bacterial pool, thus favoring certain bacterial taxa. Conversely, the few phylotypes specifically detected in some sites are probably due to localized external inputs introducing allochthonous microbial groups.

Long-Term Environmental Monitoring in an Arctic Lake Polluted by Metals under Climate Change

Lake Kuetsjarvi (in the lower reaches of the Pasvik River, Murmansk Region, Russia) in the border area between Russia and Norway, is one of the most polluted water reservoirs in the European Arctic. The operation of the Pechenganikel Smelter located on its shores has led to the extremely high concentrations of heavy metals observed in the waters and sediments of the lake. Long-term comprehensive studies of the ecosystem of Lake Kuetsjarvi have made it possible to identify the response of its components to the global and regional change in the environment and climate as a whole, resulting in increased water toxicity and eutrophication, reduction in the number of stenobiont species of aquatic organisms against the background of an increase in the number of eurybiontic and invasive species. Modern communities of Lake Kuetsjarvi are the result of a combination of long-term changes in the abiotic environment and biotic interactions. Heavy-metal pollution of Lake Kuetsjarvi, observed since the 1930s, has led to the formation of a community that is resistant to this type of impact and supports large populations of adapted species. Adaptations of communities to the dynamics of the environmental conditions that their members are exposed to include changes in the species composition, quantitative indicators, ratios between individual taxonomic groups, and the population structure. The development of sympatric forms that differ in the ecological niches they occupy, morphology, and life cycle strategies, including the transition to a short-cycle survival strategy, allows whitefish to remain the dominant species and maintain high population numbers. Unlike the organismal level, responses to medium-term environmental changes on the population and community level are less specific and characterized by stronger inertia.

ДОЛГОВРЕМЕННАЯ ДИНАМИКА ОСНОВНЫХ КОМПОНЕНТОВ ЭКОСИСТЕМЫ ОЗЕРА КУЭТСЪЯРВИ (СИСТЕМА РЕКИ ПАСВИК, МУРМАНСКАЯ ОБЛАСТЬ)

Озеро Куэтсъярви (нижнее течение р. Пасвик, Мурманская область), расположенное в приграничной зоне между Россией и Норвегией, является одним из наиболее загрязненных водоемов Евро-Арктического региона. В результате деятельности расположенного на его берегах плавильных цехов металлургического комбината «Печенганикель» в водах и донных отложениях озера отмечаются чрезвычайно высокие концентрации тяжелых металлов. Долговременные комплексные исследования экосистемы оз. Куэтсъярви позволили выявить ответные реакции ее компонентов на глобальные и региональные изменения окружающей среды и климата в целом, результирующие в усилении токсификации вод и их эвтрофировании, сокращении численности стенобионтных видов гидробионтов на фоне возрастания численности эврибионтных и инвазивных видов. Современные сообщества оз. Куэтсъярви представляют собой результат воздействия комплекса факторов многолетних изменений абиотической среды и биотических взаимоотношений. Загрязнение оз. Куэтсъярви тяжелыми металлам, длящиеся с 30-х годов прошлого века, привело к формированию сообщества, устойчивого к данному виду воздействия и поддерживающего высокую численность толерантных и адаптированных организмов. Адаптации сообществ к динамике условий существования организмов, выражаются в изменениях видового состава, количественных показателей, соотношения отдельных таксономических групп, структуры популяций. Формирование симпатрических форм, различающихся экологическими нишами, морфологией, стратегиями жизненного цикла, включая переход на короткоцикловую стратегию выживания, позволяет сигу оставаться доминирующим видом и поддерживать высокую численность популяции. В отличие от организменного уровня, ответные реакции на среднесрочные изменения окружающей среды популяций и сообществ более инерционны и менее специфичны.

A FLUID IRON CURTAIN

The Pasvik River shapes the greater part of the border between Russia and Norway. This body of water was a site of Norwegian–Soviet energy cooperation from the 1950s until the late 1970s. Norwegian firms constructed four hydropower stations in a strategically sensitive area. Drawing on Soviet and Norwegian archival materials, this study analysed the heterogeneous interests and negotiation processes that resulted in long-term hydropower cooperation. The powerhouses were designed to produce both electrical and political energies for transfer across the border. These infrastructural projects fit into the contemporary narrative of peaceful coexistence and prompted a firm cooperation between the two countries. Norwegian workers built power plants on Soviet soil, thereby legitimizing the Norwegian social democrats’ policy of rapprochement. The Soviet government and media portrayed the construction as physical proof of good neighbourly relations. Not only state actors but also members of the Norwegian–Soviet Friendship Society aimed to appropriate the powerhouses for their specific goals. They worked to soften the border regime between the two countries, thus initiating a locally limited visa-free entry zone. However, this project was short-lived because Norwegian–Soviet cooperation at the border was restricted to the realm of energy production.

Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system.

Habitat discontinuity, anthropogenic disturbance, and overharvesting have led to population fragmentation and decline worldwide. Preservation of remaining natural genetic diversity is crucial to avoid continued genetic erosion. Brown trout (Salmo trutta L.) is an ideal model species for studying anthropogenic influences on genetic integrity, as it has experienced significant genetic alterations throughout its natural distribution range due to habitat fragmentation, overexploitation, translocations, and stocking. The Pasvik River is a subarctic riverine system shared between Norway, Russia, and Finland, subdivided by seven hydroelectric power dams that destroyed about 70% of natural spawning and nursing areas. Stocking is applied in certain river parts to support the natural brown trout population. Adjacent river segments with different management strategies (stocked vs. not stocked) facilitated the simultaneous assessment of genetic impacts of dams and stocking based on analyses of 16 short tandem repeat loci. Dams were expected to increase genetic differentiation between and reduce genetic diversity within river sections. Contrastingly, stocking was predicted to promote genetic homogenization and diversity, but also potentially lead to loss of private alleles and to genetic erosion. Our results showed comparatively low heterozygosity and clear genetic differentiation between adjacent sections in nonstocked river parts, indicating that dams prevent migration and contribute to genetic isolation and loss of genetic diversity. Furthermore, genetic differentiation was low and heterozygosity relatively high across stocked sections. However, in stocked river sections, we found signatures of recent bottlenecks and reductions in private alleles, indicating that only a subset of individuals contributes to reproduction, potentially leading to divergence away from the natural genetic state. Taken together, these results indicate that stocking counteracts the negative fragmentation effects of dams, but also that stocking practices should be planned carefully in order to ensure long‐term preservation of natural genetic diversity and integrity in brown trout and other species in regulated river systems.

Metal Resistance in Bacteria from Contaminated Arctic Sediment is Driven by Metal Local Inputs.

Anthropogenic impact over the Pasvik River (Arctic Norway) is mainly caused by emissions from runoff from smelter and mine wastes, as well as by domestic sewage from the Russian, Norwegian, and Finnish settlements situated on its catchment area. In this study, sediment samples from sites within the Pasvik River area with different histories of metal input were analyzed for metal contamination and occurrence of metal-resistant bacteria in late spring and summer of 2014. The major differences in microbial and chemical parameters were mostly dependent on local inputs than seasonality. Higher concentrations of metals were generally detected in July rather than May, with inner stations that became particularly enriched in Cr, Ni, Cu, and Zn, but without significant differences. Bacterial resistance to metals, which resulted from viable counts on amended agar plates, was in the order Ni2+>Pb2+>Co2+>Zn2+>Cu2+>Cd2+>Hg2+, with higher values that were generally determined at inner stations. Among a total of 286 bacterial isolates (mainly achieved from Ni- and Pb-amended plates), the 7.2% showed multiresistance at increasing metal concentration (up to 10,000ppm). Selected multiresistant isolates belonged to the genera Stenotrophomonas, Arthrobacter, and Serratia. Results highlighted that bacteria, rapidly responding to changing conditions, could be considered as true indicators of the harmful effect caused by contaminants on human health and environment and suggested their potential application in bioremediation processes of metal-polluted cold sites.

Heavy metal tolerance and polychlorinated biphenyl oxidation in bacterial communities inhabiting the Pasvik River and the Varanger Fjord area (Arctic Norway)

Heavy metals (HMs) and polychlorobiphenyls (PCBs) enter the Arctic environment through a variety of anthropogenic sources with deleterious effects towards biota and public health. Bacteria first transfer toxic compounds to higher trophic levels and, due to the tight link existing between prokaryotic community functions and the type and concentration of contaminants, they may be useful indicator of pollution events and potential toxicity to other forms of life. The occurrence and abundance of HM-tolerant and PCB-oxidizing bacteria in the sub-Arctic Pasvik river area, heavily impacted by anthropogenic modifications, was related to HM and PCB contamination. This latter more likely derived from local inputs rather than a global contamination with higher PCB and HM amounts (and higher bacterial viable counts) that were determined in inner and middle sections of the River. Finally, a panel of bacteria with potential applications in the bioremediation of cold environments were selected and phylogenetically identified.

Rapport fra utgravning: "Fosslund" (g.nr. 16/1), Sør-Varanger k., Finnmark

Excavation report. Excavation of house-pit at "Fosslund" in Pasvik River Valley 2000, as part of PhD project. Trench through wall and floor, uncovering a fire-pit with clay (some possibly from vessels) and burnt bones and quartz. Some quartz scrapers and flakes in floor area. Radiocarbon dated to 405–205 BC and 200–35 BC.Related publication:Skandfer, M. 2012. " Change and Recollection: House Structures and Social Identification in Finnmark, Artic Norway 2400 BC - AD 300." In Damm, Charlotte and Saarikiivi, Janne (eds.): Networks, Interaction and Emerging Identities in Fennoscandia and Beyond. Papers from the Conference held in Tromsø, Norway, October 13-16 2009. Suomalais-Ugrilainen Seura / Finno-Ugrian Society 2012 pp. 155-176 (2017-06-12)Related reports:http://doi.org/10.7557/7.4334http://doi.org/10.7557/7.4311http://doi.org/10.7557/7.4314http://doi.org/10.7557/7.4313

Assessment of the Ecological State of the Arctic Freshwater System Based on Concentrations of Heavy Metals in the Bottom Sediments

The ecological state of the Inari Lake–Pasvik River system, the largest in northern Fennoscandia (in the near-border territories of Russia, Norway, and Finland) was assessed based on studying concentrations of heavy metals (HM) in the bottom sediments (BS). The water body (Kuetsjarvi Lake) contaminated with liquid wastes from the Pechenganickel smelter contains the highest HM (Ni, Cu, Co, Zn, Pb, Cd, Hg, and As) concentrations in the uppermost BS layers. In water bodies down and up the Pasvik River of the discharge site of waste waters from the smelter, the uppermost BS layers do not contain elevated concentrations of contaminating HM typical of the area (Ni, Cu, Co, Zn) but do contain higher concentrations of chalcophile elements (Pb, Cd, Hg, and As), which come mostly from trans-border sources. In the lakes receiving domestic wastes, phosphorus concentrations increase up the vertical section of the BS, which may suggest the development of eutrophication processes. They result in reducing conditions in the bottom waters and uppermost BS layers and, consequently, the transfer of ionic species of elements susceptible to variations in the redox potential from BS to waters. This process leads to depletion of the uppermost BS layers, first of all, in Fe and Mn and also in HM adsorbed on the surface of Fe and Mn oxides and hydroxides. In the water bodies that have preserved their oligotrophic nature, the uppermost BS layers were determined to accumulate Fe and Mn, whose concentrations are up to 50 times higher than the Earth’s crust average and the background values. Quantitative parameters of the factors and degrees of contamination are determined, as also are the ecological risk indexes for the contamination of the water bodies with HM, using the L. Hakanson method adapted to the regional conditions. The nonessential metals Hg and Cd, which are the most toxic and dangerous for hydrobionts, are determined to be the most ecologically hazardous in all of the water bodies. Nickel is a highly ecologically hazardous element in a single water body: Kuetsjarvi Lake. In all other water bodies of the Inari Lake–Pasvik River system, elements emitted and discharged by the smelter (Ni, Cu, Co, Pb, and As) are moderately and low ecologically hazardous for the aquatic systems.

Impact of an iron mine and a nickel smelter at the Norwegian/Russian border close to the Barents Sea on surface soil magnetic susceptibility and content of potentially toxic elements

An important problem in soil magnetometry is unraveling the soil contamination signal in areas with multiple emitters. Here, geophysical and geochemical measurements were performed at four sites on a north - south transect along the Pasvik River in the Barents Region (northern Norway). These sites are influenced by depositions from the Bjørnevatn iron mine and a Ni-Cu smelter in Nikel, Russia. To relate the degree and type of pollution from these sources to the corresponding magnetic signal, the topsoil concentrations of 12 Potentially Toxic Elements (PTEs) (As, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb, Se, Ti, Zn), were determined, magnetic hysteresis parameters and thermomagnetic properties were measured. In situ magnetic low-field susceptibility decreases from north to south with increasing distance from the iron mine. Relatively large magnetic multidomain grains of magnetite and/or titanomagnetite are responsible for the strong magnetic signal from the topsoil close to Bjørnevatn. These particles are related to increased enrichment factors of As, Mo and Cu, yielding high positive correlation coefficients with susceptibility values. At a site furthest away from the iron mine and located 7 km from the Ni-Cu smelter magnetic susceptibility values are much lower but significant positive correlations on the level of p < .1 with 8 PTEs (Ni, Cu, Co, Se, As, Zn, Cd, Cr) have been observed. The magnetic signal in this area is due to fine-grained primary sulphides and secondary fine-grained magnetite and/or maghemite.

Bacterial isolates from the Arctic region (Pasvik River, Norway): assessment of biofilm production and antibiotic susceptibility profiles.

Bacterial biofilm production is recognized as a strategy that helps aquatic bacteria in resisting to the presence of several kinds of pollutants, including antibiotics, in the bulk environment. The Pasvik River, located between Norway, Russia and Finland, is a sub-Arctic site polluted by wastes from metallurgic and mining activities. In order to study whether and to what extent bacteria are able to produce biofilms, and to assess whether this physiological characteristic influences their resistance to antibiotics, an investigation was performed on bacteria isolated from water and sediment collected along the Pasvik River course during two surveys (May and July). Bacterial strains were screened for their biofilm production and profiles of susceptibility to antibiotics. Results showed that biofilm formation was a widespread characteristic of the isolates. Most of them were also resistant to several antibiotics, such as ampicillin (100% of the isolates) as well as cefazolin, cefoxitin, ceftriaxone, mezlocillin, nitrofurantoin and sisomicin (90% of the total strains). This study shows a significant association between biofilm formation and antibiotic resistance at inner stations both in water and in sediments in May only. This suggests that in Pasvik River colder temperature may stimulate bacterial aggregation into biofilm and simultaneously decrease bacterial susceptibility to antibiotics; since the occurrence of antibiotic resistance has frequently been linked to the presence of pollutants, this result could represent a strategy of bacterial survival under altered environmental conditions.

Histopathological characteristics of Coregonus fishes under the impact of metal industry

This article provides results from monitoring studies of the state of common whitefish (Coregonus lavaretus L.) inhabiting the border Pasvik River and a number of lakes of Northern Fennoskandia. The water catchment area is subject to a significant contamination by coper, nickel, and sulfur dioxide due to the airborne transport of emissions from the Pechenganikel smelter. The ecological situation near the smelter is evaluated as very unfavorable and requires constant control, including the monitoring of aquatic systems. We used histopathologies of gills, liver, and kidneys as biomarkers to diagnose the state of sparsely rakered whitefish. Changes in their cellular structure were diagnosed and classified. The presence of the revealed abnormalities is associated with long-term aerotechnogenic stress on the investigated water bodies. The possibility of using the obtained data for assessing water quality has been considered.

Specific features of accumulation of Cu, Ni, Zn, Cd, and Hg in two whitefish Coregonus lavaretus (L.) morphs inhabiting the Inari-Pasvik lacustrine-riverine system

The spatial regularities of the accumulation of heavy metals in two ecological morphs of whitefish of the Pasvik River (northern Fennoscandia) under long-term pollution have been investigated. It was revealed that the accumulation of priority pollutants (Ni and Cu) in fish declines the further you go from the source of pollution. The concentration of Hg in the tissues of fish from the Pasvik River was determined for the first time. It was found that metal accumulation depends on the ecological morphs of the fish, the natural conditions of the waterbodies, and the intensity of pollution. The specific features of heavy-metal distribution in the “bottom sediment-fish organism” system were determined. These may indicate the heterogeneity of the pollution processes of the Pasvik system of waterbodies.

Genetic structure in relation to movements in wild European grayling (Thymallus thymallus) in three Norwegian rivers

The relationship among genetic structure, movements, and barriers was studied in European grayling (Thymallus thymallus). Gene flow is closely related to movement patterns, and genetic differentiation may be negatively correlated with movement. Grayling movements in the Glomma River (8149 tagged) and the neighboring Trysilelva River (4070 tagged) were different among sampling sites. Most individuals were stationary (±0.5 km), but some individuals moved long distances (≤153 km). The movement data indicated potential for gene flow between the two upstream sampling sites in the Glomma River and between the two midstream sites in the Trysilelva River. Allele frequencies at seven microsatellite loci indicated pairwise differentiation across sampling sites. Genetic structuring was generally consistent with the observed movement pattern. Isolation-by-linear-distance or number of potential barriers (dams, lakes) was not significant among sites within streams or among sites within the two southern streams. They were significant, however, if two outlying northern populations in the Pasvik River were included. Our results suggest that although grayling may move long distances, they also exhibit genetic structuring within large continuous river systems. Fish movement, often the result of flexible and adaptive behavioral strategies, is the ecological mechanism for gene flow. Movements may be the adaptive link explaining how environmental conditions affect genetic structuring.