Recent Submissions

  • Crust-mantle branch of the global carbon cycle and origin of deep-seated hydrocarbons

    Sorokhtin, N. O.; Nikiforov, S. L.; Kozlov, N. Ye. (2018)
    The processes of multi-stage and polycyclic transformation and transfer of carbon in the crust and mantle have been described. The sediments drawn in the plate underthrust zones break down, become transformed and altered by metamorphic events, and part of the newly formed carbon compounds is transferred by the mantle convective currents to rift zones of the mid-oceanic ridges and carried up to the surface as hydrocarbons of various composition and carbon dioxide. This material becomes re-deposited on the sea floor as sediments forming carbonaceous and carbon-bearing units. As a result of multi-stage mechanism of physical and chemical transformations in the crust-mantle areas of the Earth hydrocarbon compounds acquire features of abiogenic origin remaining, in fact, exogenic. The revealed crust-mantle carbon cycle represents part of a global process for the cyclic carbon transfer from the atmosphere to the mantle and back. The scale of its manifestation is likely not so wide, and numerous small (mm and portions of millimeters) particles of exogenic substance and dispersed carbon drawn in the plate underthrust zones form a stable geochemical tail of the crustal direction in the mantle propagating in the plane of convective currents motion. The scale of this process may be indirectly suggested by the volumes of hydrocarbon and carbon dioxide de-gassing and hydrogen in the rift systems of the Earth crust. The amount of generated hydrocarbon gases with deep-seated origin cannot form large gas and oil-and-gas fields since their significant part is transferred to the atmosphere. Just some portion of compounds may be deposited in oceanic sediments and generate gas-hydrate pools.
  • Change of the high-latitude ionosphere during heating by a powerful short radio wave of the EISCAT/Heating complex according to signals of the GLONASS satellite and the incoherent scattering radar

    Tereshchenko, E. D.; Milichenko, A. N.; Rietveld, M. T.; Chernyakov, S. M.; Shvets, M. V. (2018)
    Представлены результаты наблюдений изменения температуры, электронной концентрации и полного электронного содержания высокоширотной области ионосферы во время ее модификации мощным коротковолновым радиоизлучением нагревного комплекса EISCAT/Heating (Тромсё, Норвегия) по данным сигналов спутников ГЛОНАСС и радара некогерентного рассеяния УВЧ ЕИСКАТ (Тромсё, Норвегия). Рассмотрена геометрия пролетов спутников ГЛОНАСС и GPS для условий работы нагревного комплекса в Тромсё. Показано, что во время экспериментов на комплексе EISCAT/Heating для изучения модифицированной структуры высокоширотной ионосферы удобнее использовать спутники ГЛОНАСС. Параметры орбит этих спутников позволяют исследовать изменения полного электронного содержания в направлении вдоль геомагнитной силовой линии в месте наблюдения. Показано, что во время нагрева ионосферы мощной коротковолновой радиоволной ее структура приобретает неоднородный характер. Работа нагревного комплекса в режиме "включено – выключено" вызывает появление волнообразных вариаций полного электронного содержания с периодом, близким к периоду нагрева. Основными особенностями поведения полного электронного содержания при непрерывном нагреве ионосферы в направлении магнитного зенита по данным спутника ГЛОНАСС явились уменьшение полного электронного содержания в центральной зоне диаграммы направленности антенны нагревного комплекса, т. е. в направлении магнитного зенита, и присутствие повышенных значений полного электронного содержания на краях зоны нагрева. По данным радара некогерентного рассеяния во время нагрева ионосферы вблизи направления на магнитный зенит формируется область повышенной электронной температуры и электронной концентрации. Поведение полного электронного содержания по данным спутника ГЛОНАСС и радара некогерентного рассеяния во многом соответствует друг другу, кроме этой области. Высказываются предположения о причинах такого несоответствия.
  • Change of the global climate regime at the turn of the XX–XXI centuries

    Ponomarev, V. I.; Dmitrieva, E. V.; Shkorba, S. P.; Karnaukhov, A. A. (2018)
    Rapid change in the planetary climate regime at the turn of the XX and XXI centuries has been revealed based on the analysis of the observations' data. With respect to the previous climatic regime, evaporation and a latent heat flux have increased from most of the surface of the World Ocean. Recent climatic regime in the XXI century is characterized by a significant increase in the number of strong cyclones, storms, sum of precipitation in wet areas with maritime climate. The number of hazardous extreme weather events is mostly increased in the ocean – continent marginal zone, including the Far East of Russia. The increase in precipitation in 2004 and extreme precipitation in 2015–2016 within the catchment of Lake Khanka in the South of the Russian Far East led to a catastrophic spill of this lake. During the first 17 years of the XXI century the number of extreme precipitation and floods in the warm season has increased in most of the marginal zones of Eurasia and North America. Winter snowfall is also amplified in the zone of temperate latitudes over many continental regions. The observed increase in precipitation is caused due to growth in both the water vapour content in the atmosphere over the ocean and the meridional transfer of heat and water vapour. Decrease in rainfall occurs in some continental areas, including the catchment area of Lake Baikal and the reservoirs of the Angara cascade of hydropower plants.
  • Pollution of water and bottom sediments of the Polar Front area in the Barents Sea with heavy metals

    Novikov, M. A.; Draganov, D. M. (2018)
    Pollution of the Barents Sea water and bottom sediments in the Polar Front area with heavy metals including Cu, Ni, Co, Cd, Hg, Zn, Pb and Cr has been considered based on the long-term data. The existence of a voluminous own database of Knipovich Polar Research Institute of Marine Fisheries and Oceanography (PINRO) on the content of metals in the surface layer of water and bottom sediments of the Barents Sea is the prerequisite for carrying out the research. At the first stage of the study, the data from 32 stations located in the Polar Front zone and obtained in the period from 2001 to 2013 have been derived and processed using GIS technologies and mathematical statistics from the database. Further, based on methods previously proposed by PINRO, the background values of the content of the listed metals in water and bottom sediments of the Polar Front, the zone of contact and transformation of the Atlantic and Arctic water masses have been calculated. In most cases, the values obtained have exceeded those established for neighboring water masses. As a result of the research, the maps of distribution of the pollution of sea water and bottom sediments with heavy metals have been made. Pollution is understood as the content of metals in concentrations exceeding the background level. It has been concluded about the persistent anthropogenic contamination of the Barents Sea Polar Front waters with some heavy metals, as well as of its bottom sediments with mercury in autumn period. The assumption has been made that the frontal zone accumulated the pollution coming from neighbouring contacting Atlantic and Arctic water masses. It has been shown that the pollution of the water in the frontal zone is mostly not accompanied by contamination of the underlying bottom sediments. With respect to the content of Ni, Cr and Pb in bottom sediments, one can speak of the detection of positive local geochemical anomalies.
  • Ecology and distribution of the Iceland scallop Chlamys islandica (O. F. Müller, 1776) in the Kola Вay (the Barents Sea)

    Pavlova, L. V.; Zuyev, Yu. A. (2018)
    Assessment of the current state (distribution, allocation features, size structure, habitat conditions) of the Iceland scallop Chlamys islandica settlements in the Kola Bay has been carried out. Material for the study was collected in the upper subtidal zone by scuba divers at 12 research areas. It has been established that at present in the bay the scallop is widespread. This species occurrence is higher on the hard bottom and shell rock than on the soft bottom. The scallop numbers increases from the inner to the outer region of the bay. The weight-average density varies from 0.01 to 5.56 ind/m2 and the biomass varies from 0.5 to 225.0 g/m2. The scallops can form the local aggregations with density of 15 ind/m2. The mollusks settlement density is comparable with that in other bays of the more environmentally friendly areas. The size structure of mass aggregations has a monomodal character that demonstrates a weak replenishment of shallow-water settlements by juveniles. The Iceland scallop inhabits the upper subtidal zone of the Kola Bay with the water temperature equal to 2.8–11.8 °C and the salinity – 31.4–35.6 ‰. The abundance and size composition of scallop in the middle of the bay is under the influence of illegal non-commercial fishing. The received data on distribution and dimensional structure of the Iceland scallops can form a basis for monitoring conditions of bottom fauna of the Kola Bay and also for monitoring the possible changes in the Arctic ecosystem caused by climatic fluctuations or anthropogenic influence.
  • Biological features and intraspecific variation of three-spine stickleback Gasterosteus aculeatus (Linnaeus, 1758), the Kola Peninsula

    Garmash, M. V. (2018)
    The biological characteristics and intraspecific variability of threespine stickleback, Gasterosteus аculeatus, from the estuary of the River Tuloma and lakes Venzin and Kulonga on the Kola Peninsula have been studied. Four morphotypes of threespine stickleback (trachurus with a keel, semiarmatus with а keel, leiurus with а keel, leiurus without keel) have been discovered. There are differences in the number of plates on the body of the stickleback, of plastic traits in different habitats, namely length and body height, the length of the first dorsal, middle dorsal and ventral spines. In the lakes there are morphs with a small number of plates, namely leiurus (3–6), and semiarmatus (13–16). In the estuary of the River Tuloma, the morphotype of trachurus with keel (22–26) is mostly found. The size and weight parameters of stickleback are also different in the investigated water bodies. On average, the length of freshwater stickleback is 53 mm, and the weight is 1.3 g, seawater stickleback, respectively, 72 mm and 4.4 g. These differences point to the adaptation to living in different conditions. In fresh reservoirs, the bone carapace is relieved by reducing the number of plates, while in water with a lower salinity, it is more difficult to extract the calcium needed to build bone plates, than in water with increased salinity. In the estuary of the River Tuloma during the tides there is an increase in salinity from 1 to 22 ‰, therefore, to extract calcium for building these scutes is more easily. Also, many-plate individuals after grasping by predators experience less damage than low-plate, and consequently the chances of escaping from the teeth of a predator increase. The dependence of the size-weight characteristics approximated by the power function equation of the form W = aLb has been determined. The coefficient b > 3 indicates the preservation of the shape of the body as the stickleback grows, and suggests that the rate of increment of mass is similar in the studied reservoirs.
  • The physiological state of the Fucus vesiculosus L. of the Barents Sea in a prolonged air condition

    Ryzhik, I. V.; Makarov, M. V. (2018)
    The increase in anthropogenic pressure on ecosystems necessitated the implementation of measures aimed at purifying the environment and restoring disturbed biocoenoses. To remediate the marine environment from heavy metals, radionuclides, oil products, it has been proposed to use plantations-biofilters, the biological components of which are seaweeds. Fucoids, in particular Fucus vesiculosus, have been identified as the most suitable objects as they have a high sorption activity to heavy metals, radionuclides, are able to include petroleum hydrocarbons in own metabolism. By the standard methods of plant physiological research (determination of photosynthetic activity, content of photosynthetic pigments, relative water content) the ability of F. vesiculosus to withstand prolonged exposure to air has been determined. In the experiment, the algae were placed on the netting, twisted into a roll wrapped with a tarp (to prevent drying plants) and set in different experimental conditions (in constant (8 ?C) and variable (7–19 ?C) temperatures). Algae retained the photosynthetic capacity for 30 days, but after 20 days there was a decrease in this process compared to control. After the experiment, algae recovered the level of photosynthetic capacity for one day. The total content of chlorophylls and the ratio of Chl A / Chl C during the experiment did not change, which also indicates the sustainability of the photosynthetic apparatus of F. vesiculosus. It has been shown that F. vesiculosus is able to maintain physiological activity within 30 days if it is under conditions that ensure moisture retention in the thalli is not less than 55 %. This ability expands the potential of using F. vesiculosus as an object of sanitary aquaculture: it is possible to pre-build modules of plantation-biofilter and their long transportation.
  • Chinese mitten crab Eriocheir sinensis domesticates a new habitat

    Shklyarevich, G. A.; Kuchko, Т. Yu. (2018-06-30)
    The fact of habitation of an invading species – the Chinese mitten crab Eriocheir sinensis – in the Lakhtinskaya Bay of Lake Onega has been registered. It should be mentioned that the first specimens were caught near the Pukhtinskiy Islands of Lake Onega in 1993, and in 2006 – in the Kondopoga Bay and the Povenets Bay of this lake. In 2017, the detection of the Chinese mitten crab was recorded in the Lakhtinskaya Bay of Lake Onega. The morphometric analysis data of these animals have been given. The obtained data can be used to create an information base of the studied species for further analytical examination of its growth and age, life cycle characteristics and reproduction, nutrition and migration movements, as well as for forecasting the ecological situation.
  • Current trends of breeding and cultivation of non-traditional aquaculture facilities (arctic charr, king crab, sea urchin) and aquatic processing technology

    Makarevich, P. R.; Obluchinskaya, E. D.; Dvoretsky, A. G.; Zhuravleva, N. G. (2018-06-30)
    The analysis of current scientific, technological, regulatory and methodical literature concerning cultivation and biotechnology of non-traditional species of fish (arctic charr) and valuable species of marine invertebrates (red king crab and sea urchin), as well as technology for complex processing of aquatic organisms has been carried out. The modern trends and problems of cultivation and use of these objects have been described. It has been shown that the freshwater form of Arctic charr has been successfully used in aquaculture in many countries while the aquaculture of anadromous (migratory) charr as an object of mariculture is still poorly developed and using this fish in mariculture is still too early. It is possible that in the near future as a result of breeding selection or interspecific crosses some forms with the required properties will be obtained. An analysis of published data suggests that there were no regular maintenance work in Russia on cultivation of sea urchins for obtaining their high-quality products to establish a basis (ingredients) of production for therapeutic and prophylactic purposes. The main efforts of previous studies on aquaculture of red king crab were aimed at the cultivation of larvae and postlarvae and rearing of mature males to reach an appropriate commercial quality. However, it should be noted that the methods of cultivation of crabs aged 3–5 years have not yet been well developed. There is also no information on the availability of accessible and relatively cheap ways to accelerate the molting process in crab, and it is known that just a long period of growing this crustacean (the commercial size is reached at age of 9–10 years) prevents the development of the red king crab aquaculture in a commercial scale. Modern processing of marine aquatic organisms should be based on a comprehensive, non-waste approach of producing traditional foods, therapeutic and prophylactic means and feed for aquaculture. The establishment of such a united technological cycle for processing red king crabs, sea urchins, and arctic charrs is a promising direction of development of the fish processing industry in the Murmansk region.
  • Investigation of olfaction of gray and harp seals by the operant training method

    Litvinov, Yu. V.; Pakhomov, M. V. (2018-06-30)
    The results of studying the possibility of producing a motor conditioned reflex in the gray and harp seals on the smell of an object and the ability of experimental seals to differentiate certain odours have been presented. The study has contained three stages. In the first stage the seals were trained to differentiate a container from the camphor solution from a container with distilled water. In the second – to differentiate the container with a solution of dimethyl sulfide from the container with distilled water. At these stages, the possibility of developing a conditioned motor reflex to the olfactory stimulus in the seals studied has been studied. At the third stage, the ability of experimental animals was examined by paired presentation of a container with the solution of dimethyl sulphide from a container with camphor solution. The experiment has been carried out under the MMBI aquacomplex in the Kola Bay. The experimental animals were two female gray seal (Halichoerus grypus, Fabricius, 1791) at the age of 7 years and two females of harp seal (Pagophilus groenlandicus, Erxleben, 1777) at the age of 2 years. For the experiments, the stimulants were diluted in distilled water to such concentration that the odour intensity was minimal, then the solution was placed in a container. The results of the work have demonstrated the ability of experimental seals to develop a motor conditioned reflex to olfactory stimuli and the ability to distinguish one odour from another. When teaching the differentiation of a container with a smell, the rate of training of gray and harp seal is relatively the same, while learning to differentiate two smells, harp seals are trained an order of magnitude slower than gray seals. This difference in the speed of training is probably due to the specific features of the seals studied and indicates a higher plasticity of the nervous activity of gray seals.
  • Infestation of blue mussels (Mytilus edulis L.) by trematode larvae in various areas of the Murmansk Coast of the Barents Sea

    Kuklin, V. V.; Kuklina, M. M. (2018-06-30)
    A parasitological examination of Mytilus edulis bivalves in several areas of the Murmansk Coast has been carried out. It has been established that blue mussels on the Murmansk Coast are infected by metacercaria trematodes from the families Echinostomatidae and Gymnophallidae; the former being found almost everywhere, and the second infection is noted only for the Ainov Islands region. The values of quantitative parameters of infestation in different regions have been given, the probable causes of the observed differences (taking into account the schemes of life cycles of parasites) have been considered. It has been revealed that the highest infestation of mussels is typical for the areas of large nesting colonies of birds (the Ainov Islands, Rybachy Peninsula) and on wide littoral beaches in the Kola Bay where birds actively feed at low tide. It has been established that the main limiting factors determining the degree of infestation of mussels by larvae trematodes and geographical distribution of invasion foci are the presence in the ecosystems of potential intermediate and final hosts of these helminths and the presence of sustainable ecological links between them. Water salinity and hydrodynamic conditions do not play a decisive role since both mollusks and their parasites have a high tolerance to a wide range of values of these parameters. Parasitism of metacercariae of trematodes in mussels causes negative consequences for the physiology and behavior of mollusks and can cause certain damage at artificial growing of mussels. Recommendations on the areas and conditions for the location of blue mussel plantations on the Murmansk Coast have been given. Preliminary, a parasitological examination of the littoral and sublittoral benthos and ornithological observations in the areas of location of mariculture objects are necessary.
  • Changes in activity of harp seal (Pagophilus groenlandicus) in the spring – summer period in conditions of aviary keeping

    Zaytsev, A. A. (2018-06-30)
    The results of research on changes in active forms of behavior of two representatives of harp seal (Pagophilus groenlandicus Erxleben, 1777) in the spring - summer period in conditions of aviary keeping by analyzing its quantitative characteristics have been presented. Material for this paper was gathered within a series of observations on Murmansk Marine Biological Institute's aquacomplex in Polyarny, 2011. Method of "recording individual behavioral manifestations" was used as the main method of observation. The following characteristics have been used as parameters for assessing animal behavior: the mean duration of apnea, the mean duration of animal being on surface, the number of surfacing per minute, the percentage of being underwater and on the surface from the total budget of time, the percentage of being on platform and resting in water from total budget of time. A comparison has been made between the behavior parameters of each animal, and the individual characteristics of their behavior have been described. The gathered data have allowed us to consider possibility of influence of some environmental factors on behavior of harp seals. The impact assessment has been carried out based on the values of the following factors: temperature of water, temperature of air, wind speed, atmospheric pressure level. The statistical analysis has not revealed any significant dependencies between animals' behavior changes and such factors as atmospheric pressure. The Spearman rank correlation coefficient has shown the presence of feedback between the surfacing rate and the water temperature for both animals, and also a positive connection between the mean duration of apnea and water temperature for one animal and the air temperature for other.
  • Migrations and movements of fish in the system "riverbed depression – river"

    Chemagin, A. A. (2018-06-30)
    The researchers have been carried out in the basin of the Lower Irtysh at the mouth of the River Konda, where there is one of the large wintering riverbed depression; the patterns of distribution of fish in different parts of the river during the period of intensive spring migrations – fish moving downstream and upstream in the "riverbed depression – river" system – have been studied; the direction and intensity of the movements of fish, its size range as in the midstream and in the coastal waters of the watercourse have been established. Migratory fish has been recorded round the clock as they passed through controlled sections of the river by hydroacoustic method using the complexes NetCor. The hydroacoustic survey has been performed simultaneously on different sections of the river in the transverse direction – as the midstream, and in coastal waters. It has been determined that the movements of fish in different areas and in different directions have high values of the correlative connection, indicating a high activity of fish in spring. Numerically, fish predominate migrating upstream. The numerical predominance of fish moving in the coastal zone in comparison with the river site located on the midstream than 2.5 times has been noted. In the coastal area among the up streaming and down streaming migrants, small and medium-sized fish (<20 cm) prevailed, and on the midstream – larger individuals dominated (>35 cm). Cluster analysis confirms the difference between the coastal and midstream zones based on the size structure of migrants. The revealed regularities reflect the mechanism for reducing energy loss and optimal distribution of fish in the river flow during the migration period.
  • Occurrence of sterile North-East Arctic cod individual

    Filina, E. A.; Makeenko, G. A. (2018-06-30)
    Based on histological analysis, cod individuals of older age groups that completely lost their reproductive capacity due to age-related gonads' degeneration have been considered. Such individuals have been found among both females and males. It has been revealed that in the gonads of sterile fish the replacement of gametes with connective tissue is taking place. According to the obtained data, the portion of sterile fish in samples among females of more than 100 cm has reached 2.2 %. The analysed sterile individuals are characterized by the drastically low gonadosomatic index while gepatosomatic index is mostly above the average. The reasons of age related sterility of the Barents Sea cod have not been discovered yet. The main role of age related fish reproductive condition is considered to be linked to hormonal regulation distortion of sexual cycle. Studying the distortion in the cod reproduction resulting in spawning skips or fish sterility is believed to be significant not only in theory, but in practice as well. Mature females' biomass is usually applied as reproductive potential indicator. However, the reproductive disorder leading to spawning skips affects reproductive abilities of the species that should be taken into account while estimating total allowable catches. In order to monitor abundance of sterile individuals of the Barents Sea cod, it has been proposed to add its maturity scale with VII stage for fish without reproductive capacity.
  • Aminoacids composition of muscular tissue of Coregonus lavaretus L. (the Kola Peninsula)

    Mishanina, L. A. (2018-06-30)
    The studies of the protein aminoacid composition and free aminoacids of muscle tissue of different ages of Coregonus lavaretus L. from Lakes Umbozero and Lovozero (the Kola Peninsula) have been presented. The research of aminoacid spectra in separate tissues allows to some extent to evaluate the features of protein metabolism and the physiological state of the organism. Aminoacid composition of proteins has been investigated by high-performance liquid chromatography. Fractional composition of the proteins' solubility has been determined by spectrophotometry. Significant differences in the ratio of bound and free aminoacids of muscle tissue of Coregonus lavaretus L. have been substantiated. It is established that the proteins of the muscle tissue of whitefish from Lake Lovozero have a higher total content of essential aminoacids unlike whitefish from Lake Umbozero. The content of essential aminoacid leucine in the proteins of muscle tissue of whitefish from Lovozero increases significantly, which is associated with an increase in the content of salt-soluble myofibrillar fraction. The content of essential aminoacids valine and isoleucine is significantly lower in Coregonus lavaretus L. of Lake Umbozero compared to Coregonus lavaretus L. of Lake Lovozero. Perhaps the lack of these essential aminoacids will lead to the violation of metabolism in the studied fish from Lake Umbozero. The ratio of alkaline aminoacids to acidic ones in the muscle tissue of whitefish from Lake Umbozero is less than that of whitefish from Lake Lovozero. During whitefish puberty the overall pool of essential free aminoacids decreases, the pool is in inverse proportion to content of protein aminoacids.
  • Morphological development of the digestive system of Atlantic salmon Salmo salar L. in the Umba farm during the endogenous feeding

    Livadina, L. V.; Anokhina, V. S. (2018-06-30)
    The morphological and histological characteristics of the digestive system ontogenesis in hatchery of the Atlantic salmon larvae during the endogenous feeding period have been given. An analysis of a number of articles updating information on modern studies of the digestive system in the early ontogeny of various groups of fish has been carried out. The samples were collected at the Umba hatchery in 2015–2016. The authors have performed morphological and histological analyses of embryos and larvae, histological examination of the digestive system of larvae during the transition to exogenous nutrition, the establishment of biological age at the time of certain events in the ontogenesis of the digestive system. Actual values of the biological age of Umba hatchery larvae, at which they shift to the mixed (580 tau-somite) and exogenous (630 tau-somite) feeding have been determined. The obtained results have been compared with the literature data when development of Atlantic salmon larvae takes place in conditions with controlled temperature. Variation in biological age values, when formation of the digestive system structures takes place, has pointed at the functional and morphological differences in ontogenesis of the Atlantic salmon from natural and artificial water circumstances. Development of the Atlantic salmon larvae after hatching in cold-water conditions (3–4 ?С, the Umba hatchery), sequence of the digestive system structures composition, and establishment of the functional readiness to food assimilation has been shown. In this period the growth rate of larvae has been evaluated. The organs responsible for exogenous feeding have been divided into 3 groups, and analysis of their ontogenesis has been performed. It has been recommended to start exogenous feeding with 15–20 % of yolk in presence, at the biological age of 540 tau-somite, 45–48 days after hatching in our case.
  • Weight growth of different generation of the trout Parasalmo mykiss on Lake Imandra

    Kalinina, N. R.; Anokhina, V. S.; Kravets, P. P.; Tyukina, O. S. (2018-06-30)
    The averaged indicators of the weight growth of four generations of trout at different temperatures in the time interval of the life cycle from the transfer of larvae to cultivation until the fish reaches a portioned commercial weight of 400 g when the first withdrawal of products for sale takes place have been analyzed. It has been shown that fish of different generations passes into the weight category "goods" sequentially, but after reaching different ages, while there is no direct correlation between the terms "generation formation" – "first withdrawal for sale". According to our data the most intensive weight growth of fish has been noted in the temperature range equal to 8–13 °C. An increase in the water temperature in the cages to 15–18 °C has led to a slowdown, and then to the suspension of the accumulation of fish biomass. In cages operating in the area of Kola NPP heated water trout of April generation gains the commercial weight of 400 g in 7–8 months after landing of larvae for cultivation, November trout – after 15 months. Trout of October and January generation reaches commercial weight at 11 and 9 months, respectively. The stretching of timing of biomass accumulation is most pronounced in the autumn generation of trout. It has been found that the greatest increase in weight per unit body (145.1 mg per day) is provided by the trout of the January biological group, the smallest – by the November trout (75.8 mg per day). The energy reserve of heat allowing for differently derived individuals to reach a commodity weight of 400 g, is in the range from 3 320 to 5 300 degree-day.
  • Ice gouging effects on the eastern Arctic shelf of Russia

    Libina, N. V.; Nikiforov, S. L. (2018)
    Results of the latest geological and geophysical marine cruises indicate activating of natural risks (or hazards) processes connected with ice gouging, permafrost melting, landslides, coastal thermoerosion and seismic activity. These processes represent great risks for all human marine activities including exploitation of the Northern Sea Route (NSR). One of the most dangerous natural processes is ice gouging, which results in the ploughing of the seabed by an underwater part of ice bodies. Ice gouging processes can create some emergency situation in the construction and operation of any underwater engineering structures. Natural seismoacoustic data obtained within the eastern Arctic shelf of Russia have recorded numerous ice gouging trails both in the coastal shallow and deep parts of the shelf as well. Modern high-resolution seismic devices have allowed receive detailed morphology parameters of underwater ice traces. The actual depth and occurrence of traces of the effect of ice formations on the bottom significantly exceed the calculated probability of occurrence according to ice conditions. Seismic data have allowed classify all these traces and subdivide them on modern coastal and ancient (or relict) deep ones. During Late Quaternary sea level down lifting the absence of cover glaciation did not exclude the presence of powerful drifting ice that produced ice gouging processes in the present deep part of the sea. Afterwards during sea level up lifting ice gouging follows to the sea level changes. In this case there could be destructed some dense clay dewatered sediment layer formed during the regression period. Further, during the repeated transgressive-regressive sea level fluctuations the generated ice traces could be frozen and thus preserved until our days. Modern coastal ice traces into marine shallow are the result of nowadays interaction of drifting ice and seabed that in conditions of global climate warming are activated and represent natural risks along the NSR.
  • Distribution of background contents of elements in sediments of Lake Imandra

    Dauvalter, V. A.; Kashulin, N. A. (2018)
    The background contents of the elements in the sediments of the largest lake of the Murmansk region – Imandra – have been investigated. The background concentrations values of the elements have been determined in the deepest parts of the collected sediment cores. The sedimentation rate in the lakes of North Fennoscandia, including the Murmansk region, is on average 1 mm per year, and the range is between 0.3 and 3 mm/year. The collection of sediment cores 20–25 cm long has been carried out during the study of Lake Imandra. Industrial development of unique deposits of sulfide and apatite-nepheline ores on the watershed of Lake Imandra started in the early 30s of the last century. Consequently, the natural background element contents are fixed in the lower layers of the collected sediment cores. Two groups of elements have been identified by the mathematical statistics methods (correlation and factor analysis): the first group is heavy metals, the second group is alkaline (Na and K) and alkaline-earth metals (Ca, Mg and Sr), Al and P. These elements are in elevated contents in the rock-forming minerals on the catchment area of Lake Imandra: the first group is in the northern part of the catchment area (sulfide copper-nickel ores of Monche Tundra), the second group is in the southeastern part of the catchment area (apatite-nepheline deposits of the Khibiny Alkaline Massif). The largest average background contents of heavy metals (except Co, Pb and As) are noted in the northern part of the Bolshaya Imandra; Ca, Na, Sr, Al and P – in the southern part of the Bolshaya Imandra; Mn – in the Yokostrovskaya Imandra, and Fe – in the Babinskaya Imandra, which is associated with specific conditions for the formation of oxides and hydroxides of these metals in the sediments. The highest background contents of K and Mg are noted in the Babinskaya Imandra, which may be due to the wide distribution of clay minerals with a high content of these metals.
  • Zoning of the White Sea catchment area by the degree of continental runoff influence on the marine environment

    Bulavina, А. S. (2018)
    Methodologies for the integral evaluation of the potential impact of continental runoff on the marine aquatic environment have been developed and tested in relation to the catchment area of the White Sea. Integral indicators of pollution potential (PP) and self-purification capacity (SPC) of the river waters have been calculated within the boundaries of the hydrologic areas. The following indicators have been used to calculate the PP: the volume of wastewater and the population density in the catchment area (anthropogenic components of pollution), sediment load (a natural component of pollution). Such natural settings of the catchment as the lake percentage, woodiness and the role of topography in self-purification of rivers have been used to calculate the SPC. The quality of river waters, entering the sea, is the result of the ratio of the proposed integrated indicators. On the basis of the quantitative ratios of PP and SPC, the zoning of the catchment area according to the degree of the negative impact of river waters on water quality in the White Sea has been performed. The resulting zoning scheme is demonstrated as a holistic picture, representing a complex of natural-economic factors on the river catchments of the White Sea basin. It has been revealed that river runoff from a considerable part of the catchment area has not a significant negative impact on the water quality on the White Sea. The greatest pollution effect on the waters of the White Sea has the Northern Dvina River and the Niva River. The obtained data are well correlated with the data of hydrochemical observations in the bays of the White Sea. The objectivity of integrated assessment has been provided by the base on a large number of field data and the exception of the indicators that have not quantitative expression. The obtained results can be used to develop scientifically valid environmental programmes and to plan industrial development in the catchment area.

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