Hydrocarbon concentrations in water and sediments from UK marine waters,determined by fluorescence spectroscopy

Between January 1978 and September 1979 samples of subsurface (1 m) water and surface sediment were collected from sites in the North Sea, English Channel, Irish Sea and a number of estuarine areas. These have been analysed by fluorescence spectroscopy (UVF) in order to provide information on the levels of hydrocarbons generally present in UK marine waters.Total hydrocarbon concentrations (THCs) of water samples ranged from 1.1–74 μg l.^?1 Ekofisk crude oil equivalents, all values greater than 3.5 μg l.^?1 occurring inshore. In offshore areas the mean THCs were: 1.3 μg l.^?1 in the northern North Sea, 1.5 μg l.^?1 in the western Channel, 2.5 μg l.^?1 in the eastern Channel and southern North Sea, and 2.6 μg l.^?1 in the Irish Sea.THCs of sediment samples ranged from 0.27–340 μ g^?1 dry weight Ekofisk crude oil equivalents, the highest concentration being in the Queen's Channel, the main entrance to the River Mersey.     

Hydrocarbons in the modern sediments of the Caspian Sea

The presented results have been obtained in a study of the concentrations and composition of aliphatic and polycyclic hydrocarbons in bottom sediments of Volga delta branches and in its shallow zone (2009–2010), as well as the Caspian Sea proper (2010–2013). Oil hydrocarbon pollution has been found to manifest itself mostly in Volga delta branches, which, despite the low concentrations (up to 54.5 μg/g), showed higher hydrocarbons share in C_org (up to 33.8%), while the composition of alkanes suggested their oil genesis. The geochemical barrier the Volga–the Caspian Sea prevents anthropogenic hydrocarbons from entering the open parts of the Caspian. Bottom sediments in the shallow zone of the Northern Caspian, represented by coarse-grained material, are now polluted by oil hydrocarbons to a lesser extent compared with other areas. The highest concentrations of aliphatic hydrocarbons (up to 178 μg/g) were recorded in the deepsea bottom sediments of Derbent Depression and in depressions of the Middle and Southern Caspian. These areas show a higher concentration of C_org (up to 9.884%) and a low concentration of hydrocarbons in C_org (up to 0.16%), while odd high-molecular homologues (n-C₂₅–C₃₁) dominate in the composition of alkanes.     

Some results of bottom sediment monitoring in oil production area in the southeastern Baltic Sea

Monitoring studies in the area of Kravtsovskoe oil field in the southeastern Baltic Sea have been carried out since 2003. Terrigenous bottom sediments (0–5 cm layer) in the area (23 stations) are represented by all grain size types. Down to the depth of 30–50 m, these are mostly quartz sands; at depths of 60–110 m, these are terrigenous mud with C_org content of 1–3%. The concentration and distribution of toxic elements (Cu, Co, Cd, Pb, Ba, and Hg) over sediment types and bed area are the same as in the Baltic Sea as a whole: Cu, Co, Cd, Pb, and, partially, Hg are distributed in accordance with the “fraction rules” (with minimums in sands and coarse aleurites and maximums in mud); Ba distribution is independent of the sediment type. The concentrations of toxic elements tend to increase with time: the concentrations of such elements in samples (at the same stations) somewhat increase compared with their concentrations before the construction of D-6 oil platform, during its construction, and during oil production. This trend in the concentrations of toxic elements in sediments can be due to the steelwork of D-6 platform. The increase in Ba concentration is likely due to drill mud spills during exploration drilling. None of the elements shows sediment pollution in excess of MAC anywhere in the area.     

Origin of hydrocarbons in bottom sediments of the Ivankovo Reservoir

The composition of hydrocarbons (aliphatic and polycyclic aromatic) is studied in the surface layer of bottom sediments of the Ivankovo Reservoir. Their concentrations are found to be high both per dry mass and in the composition of C_org. The concentration range was 0.42 to 28.15% for C_org, 141.9 to 3451.8 μg/g for aliphatic hydrocarbons (0.2–51.2% C_org), and 28.2–9161 ng/g for polycyclic aromatic hydrocarbons ((0.04–6.58) × 10^?3 % C_org). The distribution of hydrocarbons is shown to be determined not only by the lithologic type of sediments, but also by their input from petroleum and pyrogenic sources.     

The Concentrations of Cadmium,Lead and Copper in Filtrated Baltic Sea Water Samples Collected at Two Seasons in 1969

Two research cruises on the Baltic Sea, in July and November of 1979, were made for investigating the Baltic Sea water for its contents of dissolved cadmium, lead and copper. Atomic absorption spectrophotometry and voltammetry were used as methods of investigation, the latter method having supplied slightly lower results. In the water layer of 0 … 50 m the cadmium concentrations were 0.03 … 0.05 μg/l and the lead concentrations were 0.1 … 0.2 μg/l, seasonal changes did not have any effect on them. The copper concentrations, on the other hand, were 0.4 … 1.2 μg/l in summer and 0.1 … 0.7 μg/l in autumn. Compared with ocean waters, the lead content is remarkably high. In anoxic deep waters of the Baltic Sea the concentrations of the three metals, especially that of cadmium, are very low (< 0.01 μg/l).     

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.     

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.     

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.     

Hydrocarbons of bottom sediments at the Shtokman Field in the Barents Sea

Hydrocarbon samples taken from bottom sediments of the Barents Sea in summer 2010 in two grounds near the Shtokman Gas Condensate Field were studied. The concentration of hydrocarbons was found to increase with sampling depth along with a decrease in C_org concentration. The composition of alkanes had mixed genesis: autochthonous homologues (n-C₁₆-C₁₇) dominated in the low-molecular domain, while oil ones dominated in the high-molecular domain; light polyarenes dominated in the composition of polycyclic aromatic hydrocarbons. The seepage of hydrocarbons from the sedimentary stratum and their transformation in the surface layer of bottom sediments are considered as their major source. The relatively low hydrocarbon concentrations converted to dry mass and in the composition of C_org are supposed to be due to a decrease in the intensity of fluid flows, since the hydrocarbon reservoirs of the Shtokman Field are firmly capped by an impermeable stratum of mostly clay rocks.     

Aliphatic and polyaromatic hydrocarbons in bottom sediments of offshore mouth area of the Volga

Data on the concentration and composition of aliphatic and polyaromatic hydrocarbons in the surface layer and the body of bottom sediments in Volga delta and on the northern Caspian shelf are given. Volga delta sediments are shown to contain large concentrations of organic compounds. It is established that the concentrations of organic compounds is largely dependent on the dispersiveness of sediments. Anthropogenic hydrocarbons, both oil and pyrogenic, fail to pass the marginal filter of the Volga River and do not reach the open part of the sea. Therefore, the hydrocarbons contained in the bottom sediments on the Caspian Sea shelf are mostly of natural genesis. The distribution of organic compounds in the bottom sediment strata has a complex character. In some cases, their concentration increases because of the higher flux of hydrocarbons (especially, polyarenes in the 1950s).     

Chlorinated hydrocarbons in lower continental slope fish collected near the Farallon Islands,California

During December, 1985, Dover sole (Microstomus pacificus) were collected at water depths of 500 and 1000 m and sablefish (Anoplopoma fimbria) were collected at a water depth of 1000 m in the vicinity of former low-level radioactive and chemical munition disposal sites located near the Farallon Islands, California. Liver tissues were analysed for chlorinated hydrocarbons by gas chromatography with electron capture detection (GC/ECD). Chlorinated hydrocarbons (DDTs and PCBs) were detected in all fish. Concentrations of total DDTs and PCBs in livers of Dover sole and sablefish were as high as, or higher than, those recently reported for the same species collected in heavily contaminated coastal waters of Southern California. The presence of DDTs (up to 9 μg g⁻¹, wet wt) and PCBs (up to 7 μg g⁻¹, wet wt) in fish livers may indicate extensive contamination of the coastal waters or bottom sediments in the vicinity of the Farallon Islands. Even though the definitive sources of the chlorinated hydrocarbons detected in the Dover sole and sablefish are not known, the relative proximity of the former chemical munition disposal sites indicates that these areas may be a potential source of one or both of these contaminants.     

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%.     

Untersuchungen zur Bestimmung und zum Vorkommen des Thiocyanats im Wasserkörper der westlichen Ostsee

For the gas-chromatographic determination of thiocyanate in waters two enrichment processes were used: 1) the evaporation of the water sample on the water bath and 2) the adsorptive enrichment on Wofatit EA 60. As the example of the investigation of water samples from the Baltic Sea has shown, the less selective process 1 gave higher results of measurements than the adsorptive method 2. As compared with the GDR's coastal region of the Baltic (0.4 … 5.2 μg/l), the SCN^? concentrations (1986) in the western offshore region (0.1 … 2.1 μg/l) are considerably lower. With increasing depth and growing salt content the SCN^? concentration in the Baltic decreases. Anthropogenic influences, such as the input of residual products of sewage works effluents, can be inferred from the relatively increased SCN^? concentrations in the coastal region.     

An Estimation of the Mercury Content in the Waters of the Pomeranian Baltic-Shore-Area

In the catchment area of the Pomeranian Bay an average mercury concentration of 178 ng/l in precipitation was determined. Eight different flowing waters showed mean concentrations between 105 ng/l (?upawa) and 500 ng/l (Odra), a pronounced annual cycle having been demonstrated for the concentrations and for the freights with the minimum in February/March and the maximum in August/September. The total freight of the eight rivers amounts to 19.5 t/a, the share of the Wisla being 11 t/a. The ratio between the mercury precipitation of 335 to 410 μg/m²a Hg and the run-off varies of 30 … 75 μg/m²a Hg for the individual river basins between 0.08 and 0.21. In the Baltic Sea, the mercury concentrations are 40 ng/l in the open sea, 50 ng/l in the coastal region and 290 … 390 ng/l near the estuaries. Trough the eight investigated rivers about 48 km³/a water run off into the Baltic Sea with about 20 t/a Hg. The total introduction of Hg into the Baltic Sea is estimated at 100 t/a with the river water, 35 t/a with precipitation and 35 t/a with dust.     

Iron in the Dead Sea

The distributions of dissolved and of particulate iron in the Dead Sea during the period which preceeded its overturn and thereafter (1977–1980) are reported. During 1977–1978, the vertical profiles of the iron phases revealed facets of the mixing pattern: the progressive deepening of the pycnocline, restricted mixing within the upper water mass and penetration of surface waters into the deepest layer. The inventories of particulate iron suggest resuspension of bottom sediments in November 1978 and after the overturn the gradual disappearance from the water column of iron sulfides and iron oxy-hydroxides. Fluxes of iron from and to the lake in the undisturbed meromictic Dead Sea have been estimated: it appears that diffusion of divalent iron from bottom sediments was the major source for the standing crop of iron in the lower water mass. Low settling velocities of solid particles in the dense and viscous Dead Sea is one of the causes for the relatively large concentrations of particulate iron. The rate constant for oxidation of divalent iron in Dead Sea sediment interstitial waters is larger by two orders of magnitude than in other natural waters.     

Comparison of particulate matter distribution, in relation to hydrography, in the mesotrophic Skagerrak and the oligotrophic northeastern Aegean Sea

The seasonal vertical distribution of particulate matter (PM) was studied in two contrasting areas: (a) the mesotrophic Skagerrak (in the North Sea); and (b) the oligotrophic northeastern Aegean Sea (eastern Mediterranean). Similarities and differences of the PM distribution in the two areas are assessed with respect to the prevailing hydrographic conditions and the PM composition. Hydrographic conditions in both of the areas are characterised by strong density gradients, resulting from the inflow of low-salinity water, i.e. Baltic Sea water and Black Sea water for the Skagerrak and the northeastern Aegean Sea, respectively.Enhanced primary production and particles mainly of biogenic origin characterise the mesotrophic Skagerrak, whereas five-fold lower particle concentrations appeared in the oligotrophic Aegean Sea. The input of riverine particulates was limited in both of the areas. In the Skagerrak, the strong stratification resulted in particle accumulation on/above the pycnocline and the development of pronounced intermediate nepheloid layers (INLs). The pycnocline-related INLs were formed entirely by dinoflagellates. The pycnocline hindered the vertical movement and sinking rates of particles, thus favouring primary production. Particle horizontal advection along the density discontinuities was probably enhanced. This pattern was not observed in the stratified waters of the northeastern Aegean Sea, probably due to the very low particle concentrations and/or the fact that phytoplankton maxima appeared in deeper waters. Pronounced INLs were identified in the Skagerrak below the pycnocline; these are attributed to accumulated or advected dinoflagellate skeletal remains mixed with clay mineral particles. This was revealed only by means of SEM observations. X-ray diffraction analysis could not provide information on the type of phytoplankton present, because dinoflagellates form their skeletons from organic material. Frontal stations in the northeastern Aegean Sea exhibited pronounced vertical movement of particles towards the deeper waters. Benthic nepheloid layers (BNL) were observed in the Skagerrak; these were related to the resuspended fine-grained surface sediments. In the northeastern Aegean Sea, although near-bottom current velocities were sufficient to resuspend surface sediments, resuspension occurred only episodically. The BNLs here are related mostly to near-bottom phytoplankton growth.     

Polycyclic aromatic hydrocarbons in water and sediment of the Baltic Sea

Between 1992 and 1994, the distribution of 15 polycyclic aromatic hydrocarbons (PAHs) was investigated in seawater and surface sediments of the Baltic Sea. The analysis of PAHs in seawater is very difficult due to the low concentration. High separation capability is required. A method for analysing very low concentrations of PAHs is presented. The method is based on the high-performance liquid chromatography (HPLC) with fluorescence detection. The concentrations of PAHs in seawater are discussed in relation to water depth. A seasonal variation of PAHs in seawater was observed, with lowest concentrations occurring in summer and generally higher concentrations occurring in November. According to the regional distribution, elevated concentrations of PAHs were found in coastal regions of the Baltic Sea. The regional distribution of PAHs in surface sediments of the Belt Sea and the Arkona Basin were also investigated. The relationship between the content of PAHs and the percentage of total organic carbon in sediments is discussed.     

Oil components in the mouth area of the Don R. and in the Sea of Azov: Results of many-year studies

The data given are the results of many-year studying the distribution of the concentrations of main oil components (hydrocarbons, surfactants, and asphaltene-tarry substances) in the water mass, vertically settling particulate matter, and bottom sediment cores taken from the section Lower Don-The Gulf of Taganrog-Russian sector of the Sea of Azov in summer and autumn periods in 2006–2011. Spatial and seasonal regularities in the distributions of the total concentration of oil components and the values of their ratios in water, as well as the spatial and annual features of their accumulation in bottom sediments have been established. Radiological methods have been used for layer-by-layer dating of bottom sediment cores and determine the thickness of the layer that had formed under the maximal anthropogenic impact on ecosystems. The presence of considerable amounts of hydrocarbons of modern biological origin has been revealed in all components of examined aquatic complexes.     

Hydrocarbon contamination in sediments from urban stormwater runoff

This investigation showed that urban stormwater runoff provides a significant amount of petrogenic material to receiving waters and sediments. A characteristic hydrocarbon ‘fingerprint’ for sediments and particulate matter in the Hillsborough Reservoir, Hillsborough River and upper Hillsborough Bay was provided. Determination of source material for petroleum contamination in stormwater runoff and river sediment indicated that crankcase oil was a primary contributor to sediment hydrocarbon contamination. A comparison of sediment hydrocarbons with hydrocarbons from stormwater runoff showed that the most probable source of crankcase oil-like petrochemicals found in sediment was the stormwater runoff.A comparison of hydrocarbon composition in suspended particulate matter with that of accumulated bottom sediments in the reservoir, river and bay, during a non-storm period and rising tide showed no resuspension and upriver transport of petroleum contaminated bay sediment. No special influence of the bay upon the lower river was observed relative to hydrocarbon tracers, indicating that most contaminated sediment transport was downriver during storm events. Additional studies should be performed over various tidal cycles and storm events incorporating sediment cores, sediment grain size analysis and hydrocarbon characterization at more closely spaced stations near the river mouth to address adequately the question of specific hydrocarbon pollution sources, rate of petroleum influx and persistence of petrochemical contaminants in the sediment.     

Isotopic composition and concentration of Pb in suspended particulate matter of the Irish Sea reveals distribution and sources

The isotopic composition and concentration of Pb was measured in suspended particulate matter of the Irish Sea. Aerosol, surficial and pre-industrial sediment was also analysed to provide information on sources terms. Concentrations of Pb in suspended sediments were lower than previously reported which presumably reflects the international effort to reduce Pb inputs to the environment. Lead concentrations were highest in Liverpool Bay and lowest in the western Irish Sea. A significant negative relationship between Pb and salinity suggests that present inputs and the resuspension of relict lead associated with particles in areas significantly affected by freshwater discharges are the predominant sources of Pb to the Irish Sea. The isotopic composition of Pb in the stratified region of the western Irish Sea demonstrates that atmospheric sources are also significant to this region, which is consistent with current knowledge on the hydrography. Pb isotopic ratios show that water entering the Irish Sea through St George's Channel is significantly influenced by anthropogenic inputs prior to additional contamination by direct inputs to the Irish Sea.