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.     

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%.     

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.     

Detection of aliphatic hydrocarbons derived by recent “bio-conversion” from fossil fuel oil in North Sea waters

The higher boiling point range of saturated aliphatic hydrocarbon fractions extracted from North Sea water have been re-investigated in detail with improved high resolution glass capillary columns suitable for high temperature gas-chromatography. The resulting chromatograms reveal hydrocarbon patterns, most of which have the same common feature: a smooth distribution of the long-chain n-alkanes combined with a lack of the branched alkanes normally expected for fossil fuel oil. Instead, two homologous series of iso- and anteiso-alkanes could be detected. Since this finding is always associated with traces of present or past fossil fuel oil contamination of the upper water column, these environmental n-, iso and anteisoalkanes are considered to be recently ‘bio-converted’ from fossil fuel oil hydrocarbons. They form a third group beside recent biogenic and fossil petrogenic hydrocarbons in the marine environment. Oil pollution records of the marine environment will have to take into account this group of microbial hydrocarbons.     

Functioning of the White Sea Ecosystem: Studying the Transformations of Organogenic Substances Using a Mathematical Model

Long-term observational data on hydrology, hydrochemistry, and hydrobiology are generalized and used for systems analysis of the biohydrochemical transformation processes of organic and biogenic substances in a marine environment. An ecological model with the systematized data is used to assess the annual dynamics of concentrations of organic and mineral N, P, and Si compounds and dissolved organic C and O₂ in eight water areas within the White Sea at specified conditions of water mass transport, river runoff, and water exchange with the Barents Sea. Variations in the biomasses of the major transformers of organic and biogenic substances (heterotrophic bacteria, phyto- and zooplankton, and microphytes) and their biological production were also evaluated. These characteristics serve as indicators of the state of the water environment, the presence of nutrients in it, and their import from outside.     

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.     

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.     

Petroleum hydrocarbons in the waters of major tributaries of the White Sea and its water areas: A review of available information

The White Sea is a natural analogue of arctic seas. The pollution of the sea by petroleum hydrocarbons is not high now. However, the load on sea ecosystem can increase in the nearest future because of the anticipated industrial development in its watershed, including an increase in oil, coal, and diamond production. The specific features of the nature of arctic marine systems (hydrological, ice, hydrobiological, hydrochemical, and radiation regimes), and the poor knowledge of the conditions of dispersion, transformation, and utilization of petroleum hydrocarbons in such seas make their ecological studies especially important. Petroleum hydrocarbon concentrations in the waters of tributaries and water areas of the White Sea (for 1980–2006 and 1989–2006, respectively) were evaluated using literary and authors’ data. Analysis of the collected materials shows that the majority of petroleum hydrocarbons enter the sea’s water areas with river runoff. Petroleum hydrocarbon concentrations were evaluated in major tributaries of the sea, including the rivers of Northern Dvina, Onega, Mezen, Niva, Kem, and Keret, delivering petroleum hydrocarbons into the bays of Dvina, Onega, Mezen, and Kandalaksha, water area near the Solovetskie Islands, and Chupa Bay, respectively (Bay — Gulf). Model calculations should yield within-year variations in petroleum hydrocarbon concentrations in different part of the sea (under a correctly specified load) and the conditions of their biotransformation and horizontal transport through the boundaries between areas within the sea.     

The role of biogenic hydrocarbons in the assessment of oil pollution of freshwater bodies

The results of studying the concentrations and component composition of hydrocarbons and associated oxidized hydrophobic compounds in water bodies with different degrees of oil product pollution are given. It is shown that the role of biogenic hydrocarbons in the assessment of oil pollution of freshwater bodies, especially those having high biological productivity, can be quite significant. Such assessment requires the examination of their genesis by using the proposed gas-chromatographic and luminescent criteria. The most informative object for observations in the identification of oil and biogenic hydrocarbons for the assessment of chronic oil pollution of freshwater bodies is bottom sediment.     

Carbon speciation and composition of natural microbial communities in polluted and pristine sediments of the Eastern Mediterranean Sea

Sediment samples collected from polluted (Augusta Bay) and pristine regions of the Eastern Mediterranean Sea (South Ionian Sea, Thracian Sea) were analyzed for black carbon, aliphatic hydrocarbons and phospholipid ester-linked fatty acids (PLFA). The aim of the study was to investigate the anthropogenic and biogenic inputs into the Eastern Mediterranean Sea and to evaluate the effects of refractory organic matter (e.g. black carbon) and the level of hydrocarbon contamination on benthic microbial community composition. Black carbon, generally considered to be chemically and biologically inert, comprised a significant but highly variable fraction of the sedimentary carbon pool in the analyzed sediments with a ratio to total organic carbon ranging from 0.02 to 0.66. Principal component analysis of the chemical characteristics of the sediments (organic carbon content, black carbon, bioavailable organic carbon, chlorophyll a, phaeopigments, aliphatic hydrocarbons) revealed clustering of samples along a gradient from the most productive and contaminated region of Augusta Bay to the carbon-poor and pristine sediments of the Thracian Sea. PLFA analysis revealed that gram-negative bacteria and microeukaryotes were most abundant in Augusta Bay and in the most impacted station of the Thracian Sea. The high levels of branched and odd-chain fatty acids recorded for these stations is probably linked to the elevated amounts of hydrocarbons at these stations; e.g. microbial communities may have developed the ability to degrade either naturally occurring aliphatic hydrocarbons or hydrocarbons derived from oil contamination.     

The Role of Microorganisms in the Transformation of Biogenic Substances in the Caspian Sea Ecosystem: An Assessment Based on Mathematical Modeling

A hydroecological model is used to study the transformations of biogenic-element (N, P, C, and Si) compounds in different parts of the Caspian Sea. The existing notions of the biotransformation processes of these compounds in the marine environment are formalized. The state of the marine environment is characterized based on calculated annual dynamics of biogenic element concentrations, their relationships, and internal fluxes. Relationships between the concentrations of N and P mineral components are used to establish distinctions between different parts of the sea in the conditions of primary production limited by biogenic elements, as well as the development conditions of aquatic lifeforms (nutrient consumption, release of metabolic products, and detritus formation).     

Long-term variations in the biogenic matter runoff of the Dnestr River

Long-term observation data were used to carry out comparative analysis of variations in the biogenic matter runoff of the Dnestr River over a period of fifty years. Based on data of weekly monitoring in 2002–2004, annual dynamics of biogenic matter runoff was analyzed for the Dnestr River and for Dnestr Liman. It was found out that, in spite of the “buffer” role of the latter, the contribution of biogenic substances, finding their way in the sea with the Dnestr River water, to the eutrophication of the northwestern Black Sea remains appreciable (about 60 thousand ton year^?1). Dissolved organic compounds account for 70% of the present-day biogenic matter runoff of the Dnestr River.     

Dynamics of oil product distributions in water and bottom sediments of the sea of Azov and the Black Sea after ship accidents in the Kerch Strait

The dynamics of concentrations of oil products spilled into the aquatic ecosystem as a result of accidents in the Kerch Strait is discussed. Provision is made for the analysis of the results of long-term monitoring and for the revealing of differences in concentrations and distribution of oil hydrocarbons in the Sea of Azov and in the Black Sea after emergency spills. The available information was used to outline the course of events that led to such redistribution of spilled mazut in marine ecosystems.     

Transformations of biogenic substances in Tatar Strait water (the Sea of Japan): Analysis of mathematical modeling results

The state of the marine environment (the temperature, light intensity, transparency, biogenic load) in Tatar Strait was assessed based on mean annual data from literary sources and with the use of GIS “Sakhalin Shelf.” The entire strait was divided into three regions (northern, southwestern, and southeastern), and water exchange between them for each month was estimated by using Bergen Oceanic Model. The information about the state of the marine environment and water exchange characteristics was used as input data for a hydroecological model, which enabled the assessment of annual variations of biogenic substance concentrations and biomasses of microorganisms (heterotrophic bacteria, three groups of phytoplankton, and two groups of zooplankton) in the strait regions chosen. The development conditions of microorganism biomasses within the year can be characterized by their activity indices (specific growth rates), the values of internal fluxes of biogenic substances, and calculated bioproductivity values. The calculated biogenic substance concentrations and phytoplankton bioproductivity values showed good agreement with the estimates for the Sea of Japan and Tatar Strait available from the literature.     

Biogenic hydrocarbons and their effect on oil pollution estimates of the Sea of Azov

The results of studies on the efficiency of identification criteria for the origin of hydrocarbons in the ecosystem of the Sea of Azov. Their amount in the cells of major planktonic and benthic organisms of the Sea of Azov. The share of biogenic hydrocarbons in their total amount determined by monitoring the oil pollution of the sea is also evaluated.     

Oil pollution impact on marine communities and a problem of sea water quality improvement

Sea entered pollutions, in particular oil and oil products, interact complexly with marine biota. On the one hand, oil causes disfunction of marine communities, death of some marine representatives and sometimes of the whole community. On the other hand, marine organisms and their communities transform pollutions during purification processes improving marine environment quality. It is known, that under pollution conditions the number of aquarium-inhabiting organisms is reduced and only the most resistable species are left. The study of such species opens perspectives for the creation of hydrobiological systems and their purposeful use in cleaning polluted waters and sanitation of coastal aquaria.     

Global geoenvironmental problems: Black Sea basin

The issue of the geoenvironmental state of Black Sea basin, the final basin receiving the runoff of many large rivers of the European continent (Danube, Dnieper, Don, etc.) and considerable runoff from the nearby watersheds, including Turkish, is considered. The extent and geoenvironmental consequences of the large-scale changes in the hydrology, water balance, and hydrochemistry of the sea basin under the effect hydrotechnical interception and industrial pollution of river runoff are discussed. The genetic role of Black Sea rifting in one of the world’s largest oil-and-gas-bearing basins with its inherent thermal and geochemical processes, geoenvironmental conditions, and risks is emphasized. Improved information is given about the genesis of hydrogen sulfide dissolved in seawater and related to the processes of geochemical sulfate reduction of silt water sulfates under the effect of hydrocarbon gases, which mostly form in zones of deep catagenesis of sedimentary formations and lower crust rock metamorphism. It is emphasized that the ecological stability of a sea basin showing such complex and contradictory relationships with natural and technogenic objects and processes can be ensured only by joint and well coordinated efforts of the countries of the Black Sea and nearby regions aimed on rational nature and water management, including when laying pipelines on Black Sea bed and developing the power resources of the Black Sea oil-and-gas-bearing basin.     

Biomass development and production created by microorganisms of lower trophic levels in the caspian sea ecosystem: Analysis of mathematical modeling results

The biohydrochemical features of the Caspian Sea ecosystem were estimated for its ten water areas with the use of a mathematical model describing the transformation of compounds of organogenic elements (C, Si, N, and P) and taking into account the morphometric characteristics of the water areas and long-term mean monthly values of the major characteristics of the aquatic environment. Variations in the estimated concentrations of mineral and aggregated biogenic substance fractions, microorganism biomasses (heterotrophic bacteria, three phytoplankton groups and two zooplankton groups) in different water areas of the sea were analyzed. The formation conditions of microorganism biomasses in different water areas are characterized by the analysis of their bioproductivity estimates based on evaluated internal biogenic substance fluxes.     

Development of oil hydrocarbon fingerprinting and identification techniques

Oil, refined product, and pyrogenic hydrocarbons are the most frequently discovered contaminants in the environment. To effectively determine the fate of spilled oil in the environment and to successfully identify source(s) of spilled oil and petroleum products is, therefore, extremely important in many oil-related environmental studies and liability cases. This article briefly reviews the recent development of chemical analysis methodologies which are most frequently used in oil spill characterization and identification studies and environmental forensic investigations. The fingerprinting and data interpretation techniques discussed include oil spill identification protocol, tiered analytical approach, generic features and chemical composition of oils, effects of weathering on hydrocarbon fingerprinting, recognition of distribution patterns of petroleum hydrocarbons, oil type screening and differentiation, analysis of “source-specific marker” compounds, determination of diagnostic ratios of specific oil constituents, stable isotopic analysis, application of various statistical and numerical analysis tools, and application of other analytical techniques. The issue of how biogenic and pyrogenic hydrocarbons are distinguished from petrogenic hydrocarbons is also addressed.     

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%.