Hydrocarbons in the White Sea: Their inflow and transformation in the marine environment in different regions

Literary data have been used to assess the inflow of petroleum hydrocarbons (with river runoff, precipitation, wastewaters, sea transport, and at ice thawing) into different regions of the White Sea. The hydroecological CNPSi-model was used as an instrument to reproduce the annual dynamics of hydrocarbon concentrations at their parallel inflow and subsequent transformation in the waters of the nine White Sea regions (the bays of Kandalaksha, Onega, Dvina, and Mezen; the Solovetskie Islands; the deep-water part: Bassein, Gorlo, Voronka, and Chupa Bay). The calculations were based on normal annual values of monthly variations of water temperature, light intensity, and transparency, the morphometric parameters of the regions (water areas, mean depths, and water volumes) and water exchange between the regions and with the Barents Sea (calculated by a hydrodynamic model). The calculated concentrations of hydrocarbons, the biomasses and activity characteristics of hydrocarbon-oxidizing bacteria have been analyzed (their values were estimated for the 2-m surface water layer). The results of calculations were used to evaluate hydrocarbon balances for regions and the sea as a whole. The calculations demonstrate the balanced character of hydrocarbon fluxes, the balance discrepancy for the regions being <0.1–16.1%.     

Nutrient Transport into the White Sea with River Runoff

Averaged data from long-term observations of concentrations of mineral-nutrient fractions along with fragmentary data and indirect estimates of organic-component concentrations in the tributaries of the sea (the Niva, the Onega, the Northern Dvina, the Mezen, and the Kem rivers) are analyzed. Monthly variations in the concentrations of the major nutrients in the river water flowing into the sea are characterized, and relationships between them in different seasons are determined. Annual nutrient transport into the White Sea by river water is assessed based on characteristics of river runoff and nutrient concentrations using a mathematical model. Wide variations are established in the ratios of organic and mineral fractions of nutrients delivered into the sea. The shares of mineral components in the total runoff of N_tot and P_tot into the sea are found to be equal to 18.1 and 18.8%, respectively.     

Hydrocarbons in the water, particulate matter, seston, and bottom sediments of the White Sea in the late summer

Aliphatic and polycyclic aromatic hydrocarbons were studied in water, filtration and separation particulate matter, seston, and bottom sediments with the aim to determine their concentrations and origin and compare them with the concentrations of lipids and C_org (August 2006). The effect of anthropogenic hydrocarbons was identified mostly in the Northern Dvina mouth area and in the apex of Dvina Bay. In other parts of the sea, natural compounds dominate in all examined objects, since anthropogenic hydrocarbon cannot pass through the Northern Dvina-the White Sea geochemical barrier. The low temperatures in the high-latitude water areas are shown not to reduce the rate of diagenetic processes in the sedimentary strata.     

Mathematical modeling of oil hydrocarbon transformations in different parts of the White Sea

The available observational data on variations of oil hydrocarbon concentrations in White Sea tributaries and in individual parts of the sea are analyzed, and the contributions of different external sources to marine environment pollution are evaluated. The results of calculations are used to determine the possible total input of hydrocarbons from additional potential sources—internal natural (production by microorganisms) and external anthropogenic (navigation and sea shipping), which are most active in the summer and autumn. The hydroecological CNPSi-model is used to reproduce the processes of pollution of nine areas in the White Sea by oil hydrocarbons and their subsequent biodegradation in the marine environment. The annual dynamics of hydrocarbon concentrations was calculated using the long-term annual observations of monthly variations of the temperature, light intensity, and transparency of water, data on the morphometry of sea areas (the squares, mean depths, and water volumes) and water exchange between the chosen areas, calculated by a hydrodynamic model. For large bays (Dvina, Kandalaksha), the calculated concentrations of oil hydrocarbons are shown to be in agreement with the available estimates (the mean and maximal concentrations). The annual variations of oil hydrocarbon concentrations; the biomasses, oxidation activity and bioproduction characteristics of oil hydrocarbon-oxidizing bacteria are characterized. The calculated internal fluxes of oil hydrocarbons (the inputs from different sources, horizontal transport, and biotransformation) were used to calculate their annual balances for individual areas and the sea as a whole, showing the balanced character of their fluxes with the total balance discrepancies for individual areas varying within 0.3–4.1%.     

Mathematical modeling of the ecosystem functioning conditions in the Chupa Estuary of the White Sea: Transformation of organogenic substances and bioproductivity of the marine environment

The use of a mathematical model, describing the transformations of organic and mineral compounds of C, Si, N, and P for the generalization of hydrological, hydrochemical, and hydrobiological data on nine regions in the White Sea is demonstrated. The regions examined include the head of Kandalaksha Gulf, Dvina Gulf, Mezen Gulf, Onega Bay, the Solovetskie Islands’ area, the central, deep-water part (or Basin), Gorlo, Voronka, and the Chupa Estuary. The results of modeling the transformations of biogenic substances in the water areas of the Chupa Estuary, and other gulfs and bays in the White Sea are compared and analyzed. Calculated variations in the concentrations of biogenic substances and detritus, microorganism biomasses, characteristics of their activity (specific growth rates and biomass turnover times) within a year are presented and discussed. The estimated characteristics are shown to agree with observational data. Particular attention is paid to estimating the organic matter production rates by phytoplankton and calculating balances of biogenic compounds in the Chupa Estuary.     

Mathematical modeling of marine environment pollution processes by petroleum hydrocarbons and their degradation in Caspian Sea ecosystem

The available observational data on the pollution of tributaries and areas of the Caspian Sea by petroleum hydrocarbons and products are examined. The possible petroleum input from sources in the sea is assessed using up-to-date data of satellite observations of sea surface pollution by oil films. The hydroecological CNPSi-model is applied to studying water pollution processes by petroleum hydrocarbons in ten areas chosen in the Caspian Sea and the subsequent biodegradation of those pollutants. The model calculations of the within-year dynamics of petroleum hydrocarbon concentrations use mean annual observational data on within-year variations in water mediium characteristics (water temperature, light intensity, and transparency), as well as the morphometric parameters of sea areas (the area, mean depth, and water volumes). The characteristics of water exchange between the areas were evaluated using a hydrodynamic model. The model calculations were used to characterize the within-year variations in petroleum hydrocarbon concentrations, the biomasses of petroleum-oxidizing bacteria, the characteristics of their oxidation activity and bioproduction, and the internal fluxes of petroleum hydrocarbons (their input from various sources, horizontal and vertical transport, and biotransformation) in different sea areas. Calculation results were used to compile annual balances for the processes of input and consumption of petroleum hydrocarbons in the chosen and aggregated sea areas.     

Hydrocarbons in the bottom sediments of the Northern Dvina estuary

The results of studying hydrocarbons during the flood in May 2005 are discussed. The concentration of aliphatic and polycyclic aromatic hydrocarbons are shown to match their concentrations in water areas with steady input of pollutants. Weathered oil and pyrogenic compounds dominated in their composition. The geochemical barrier the Northern Dvina River-Dvina Gulf is shown to become a filter during floods and prevents pollutants from penetrating into the White Sea.     

Hydrocarbons in the Suspension and Sediments of the Baltic Sea

The article gives the results of studying the concentration and composition of aliphatic and polycyclic aromatic hydrocarbons in suspension in surface waters at sections from the English Channel and Skagerak Strait to various regions of the Baltic Sea (2010–2015) and in water and bottom sediments of the southeastern part of the sea in the water area of the Kravtsovskoe field (2008–2015). In recent years, the surface waters of open areas of the Baltic Sea showed a decrease in hydrocarbon concentrations down to background levels (12–33 μg/L). The maximal concentration of hydrocarbons (in excess of the MAC) was recorded in different seasons in navigation areas, including the English Channel and Pregola R. mouth. In the zone of the Kravtsovskoe field, the concentration and composition of hydrocarbons in water depends on their inflow from the bank, and the same characteristics in bottom sediments, on the rate of their leakage from sediment stratum. A decline in these processes have led to a decrease in hydrocarbon concentrations in the sediments of a local area near D-6 platform to background levels (5–7 μg/g) and to the predominance of terrigenous, rather than petroleum, alkanes in hydrocarbon compositions.     

Compounds of Reduced Inorganic Sulfur in the Waters of the White Sea and the Northern Dvina Mouth

The occurrence and distribution of reduced inorganic sulfur compounds in the waters of the White Sea and the Northern Dvina mouth are studied. Universal occurrence of micro-quantities of the above compounds in the oxic marine and fluvial waters is established. The White Sea water is found to be depleted of reduced sulfur, judging by the sum of reduced S forms (<0.5 mol), as compared with that in the water of the Black and Baltic seas.     

Pelagic petroleum pollution off the south-west coast of Puerto Rico

Petroleum pollution in the form of floating tar balls and dissolved or dispersed hydrocarbons has been monitored off the south-west coast of Puerto Rico on a weekly basis since November 1980. Tar ball abundance estimates agree well with previously published data for the area. Dissolved/dispersed hydrocarbon concentrations are close to, but below, those found in the Mediterranean Sea and considerably lower than those for more polluted areas. Tar ball abundance is closely related to the intensity of southerly winds. Dissolved/dispersed hydrocarbon concentrations are highest during the fall and coincident with the highest surface water temperatures.     

The distribution and transformation of oil hydrocarbons in Onega Lake bottom sediments

The distribution of oil hydrocarbons in bottom sediments of Onega Lake was examined. Their qualitative and quantitative composition was examined by methods of IR-spectroscopy and chromatography-mass spectrometry. The background concentrations of oil hydrocarbons in bottom sediments are evaluated and the polluted area is determined. The major regularities in oil hydrocarbon transformations under natural conditions and anthropogenic impact are identified. The quantitative development of the bacterial groups that take part in the transformation of complex organic substances and oil product derivatives in the case of emergency pollution of Petrozavodsk Bay water area by oil products is demonstrated.     

Temporal and spatial trends of total petroleum hydrocarbons in the seawater of Bohai Bay, China from 1996 to 2005

The temporal and spatial distribution of total petroleum hydrocarbons (TPH) in the seawater of Tianjin Bohai Bay during 1996-2005 was investigated for the first time. TPH concentrations in 480 seawater samples collected from 16 stations during a 10-year span were quantified by ultra-violet fluorescence spectroscopy. Petroleum hydrocarbons were ubiquitous in the seawater, and their concentrations were highly variable, ranging from 23.7 to 508 μg L⁻¹. TPH concentrations in the seawater varied with seasons, showing a decreasing order of winter > spring > summer. Over the 10-year period, TPH at all stations steadily decreased. The highest values obtained were at stations near the port areas and Dagu outfall where shipping activities and land-based waste water discharges were the major sources of pollution. Our results provided the background information on the extent of TPH contamination in the seawater and highlighted the need to further control TPH pollution in Tianjin Bohai Bay.     

Hydrocarbons in water,sediment and mussels from the southern Baltic Sea

Samples of water, sediment and mussels (Mytilus edulis) from the southern Baltic Sea have been analysed for total hydrocarbons by fluorescence spectroscopy and capillary gas chromatography. The sediment and mussel samples have also been analysed for specific aliphatic and aromatic hydrocarbons by computerized capillary gas chromatography-mass spectrometry. The highest hydrocarbon concentrations in all samples occurred either inshore (particularly in Gdansk Bay) or in deep offshore basins where fine sediment accumulates.     

Estimation of biogenic substance transport by water masses in Tatar Strait

The conditions of transformations of biogenic substances and the redistribution of their concentrations in the shelf water of Sakhalin Island are studied. Preliminary works have given the results for the water area of La Perouse Strait and Aniva Bay (the Sea of Okhotsk), while this paper gives such results for Tatar Strait (the Sea of Japan). Three electronic instruments of oceanographic studies are applied: an adapted version of Bergen Oceanic Model (for the reconstruction of the space and time distribution of seawater temperature, salinity, and density; the circulation intensity of water masses; and water exchange parameters with nearby water areas and within the strait); GIS “Sakhalin Shelf” (for the reconstruction of annual variations in thermohaline characteristics on a standard grid and horizons of oceanographic stations, and the parameters of the aquatic environment); hydroecological CNPSi-model (for studying the annual dynamics of biogenic element compounds, the biomasses, biohydrochemical activity and bioproduction of microorganisms—bacteria, phytoplankton, and zooplankton, taking part in transformation of biogenic substances and petroleum hydrocarbons, as well as the internal fluxes of biogenic substances governed by the activity of microorganisms and the external load on the marine ecosystem). The results of modeling the spatial transport of biogenic substances through the outer boundaries of Tatar Strait water area and the boundaries of the three areas identified within it are presented and discussed.     

Petroleum hydrocarbon runoff in rivers flowing from oil-and-gas-producing regions in Northwestern Siberia

A method is proposed for evaluating the overland and river runoff of petroleum hydrocarbons originating from disperse pollution sources. The method is used to calculate their export from oil-and-gas-producing areas in Northwestern Siberia through the Pur River, a major artery in the Arctic region. The potential petroleum hydrocarbon input into the river is evaluated for different extent of petroleum pollution in the drainage basins of its tributaries.     

Modeling of the marine environmental pollution by petroleum hydrocarbons and their biotransformation in Tatar Strait waters

A hydroecological model is used for simultaneous studying water pollution processes by petroleum hydrocarbons and their decay under the oceanographic conditions of Tatar Strait. The model calculations were based on long-term averaged observational data on interannual variations of water temperature, light intensity, and transparency. Some oceanographic characteristics of the strait were reconstructed with the help of GIS “Sakhalin Shelf.” The strait’s water area was divided into three regions, and water exchange between them and the neighboring regions of the Sea of Japan was estimated by a hydrodynamic model. The results of the study made it possible to assess interannual variations in the concentrations and inner fluxes of petroleum hydrocarbons, oil-oxidizing bacteria biomasses, and the characteristics of their oxidation activity.     

Polychlorinated biphenyls and hydrocarbons in bottom sediments of Pechora Basin Rivers

The quantitative concentrations of 21 congeners of polychlorinated biphenyls and 16 priority polycyclic aromatic hydrocarbons were studied in bottom sediments of the Usa River, the largest Pechora’s tributary, and its tributaries located in the central part of Timan-Pechora petroleum province. In accordance with the classification of the regional and international standards, the pollution degree of bottom sediments by organic compounds of those classes was evaluated. Pollution profiles were examined and the character of the dominating source of polychlorinated biphenyls and polycyclic aromatic hydrocarbons for bottom sediments in the region under study was identified. Key words: bottom sediments, polychlorinated biphenyls, profiles of polycyclic aromatic hydrocarbons, petrogenic, pyrogenic pollution source.     

Increased levels of petroleum hydrocarbons in the surface sediments of Swedish coastal waters

Petroleum hydrocarbons in the sediments of the Bothnian Bay, Baltic proper, Öresund, Kattegatt and Skagerrak were analysed in a survey of oil pollution along the Swedish coast in 1974 and 1975. Sixty-one of these sediment stations were revisited in 1982 and analysed with the methods used in the first survey. The mean content of petroleum hydrocarbons (paraffin-naphthene fraction) in the sediment surface showed a statistically significant increase from 199 to 252 μg g^?1 dry wt. The main increase had taken place in the coastal areas. Within 0–20 km distance of urbanized areas (>20 000 inhabitants) petroleum hydrocarbons had increased from 371 to 447 μg g^?1. Sediment levels increased from 76 to 117 μg g^?1, 20–50 km from urbanized areas. The increase in these areas was equivalent to 0.119 g m^?2 yr^?1.     

Sources and distribution of aliphatic and polyaromatic hydrocarbons in sediments of Jiaozhou Bay, Qingdao, China

The composition and distribution of aliphatic (n-alkanes) and polyaromatic hydrocarbons (PAHs) were measured for the surface sediments collected at 25 sites from Jiaozhou Bay, Qingdao, China. Total n-alkanes and PAH concentrations ranged from 0.5 to 8.2 microg/gdw and 0.02 to 2.2 microg/gdw, respectively, and the distribution of both n-alkanes and PAHs showed large spatial variations in the bay. The distribution of PAHs in the sediments was predominated by the three or more ring compounds. High hydrocarbon levels were generally found in the areas associated with high anthropogenic impact and port activities in the bay. The calculated hydrocarbon indexes suggest that petroleum contamination was the main source of n-alkanes, while both pyrolytic and petrogenic sources contributed PAHs to the surface sediments of Jiaozhou Bay. In comparison to other polluted coastal sediments, the level of contamination from both aliphatic hydrocarbons and PAHs in Jiaozhou Bay sediments is relatively low at the present time.     

Environmental monitoring in a gas production area on the northwestern Black-Sea shelf

The results of long-term seasonal oceanographic observations conducted by YugNIRO from 1955 to 1991 in standard cross-sections on the northwestern shelf of the Black Sea and data obtained by monitoring oil and chemical pollution of the marine environment from 1987 to 1993 in the area of gas deposit development are systematized and statistically treated. The oceanographic conditions of pollution field formation in this region are studied. The dynamics and distribution of total concentrations of oil products and microelements (Hg, Cu, Pb, Cd, and Cr) in water and bottom sediments are examined in the areas in Karkinitskii Bay where permanent offshore platforms are operated. The obtained results are compared with data on the background environmental pollution of the Black Sea and World Ocean. A hypothesis is offered to elucidate the possible causes and mechanisms through which offshore gas production affects the hydrochemical conditions on the shelf. The monitoring data are said to be a necessary information basis for the prediction of pollution dynamics in Karkinitskii Bay with the use of a box-type hydroecological model of petroleum hydrocarbon biotransformations in water, and approaches for the use of these data for this purpose are outlined.