Ozone depletion and UV-B radiation in the Antarctic—Limitations to ecological assessment

Ozone depletion has been detected in the upper atmosphere over the Antarctic since the late 1970s. This depletion results in increased fluences of incident ultraviolet-B radiation in Antarctic environments. There is considerable information available about the chemical and physical characteristics of this atmospheric phenomenon, but the ecological impact of this annual pollution cycle has not been determined. Only a few studies on the UV-photobiology of Antarctic organisms have been initiated, and neither the extent of ecosystem modification nor the time scale for ecosystem response are known.     

The extent of hydrocarbon contamination in the marine environment from a research station in the Antarctic

Low level hydrocarbon contamination is measurable in the vicinity of Antarctic stations, N-alkane and polycyclic aromatic hydrocarbon (PAH) concentrations in seawater and sediment at Signy Station, South Orkney Islands indicated contamination was confined to within a few hundred metres of the station. Total n-alkane concentrations in seawater decreased from 7.6 to 2.6 μg l⁻¹ within 500 m of the station. All n-alkane values in seawater were within the limits of variation for oceanic waters proposed by cripps (1992), although the distribution pattern suggested pollution from the station. The total PAH concentration in seawater varied between 110 and 216 ng l⁻¹. These values showed no trend with distance from the station and were all slightly higher than for the open ocean. The n-alkane and PAH concentations in the surface sediment declined to low levels within 375 m of the station. This indicates that a large proportion of the hydrocarbons entering Factory Cove was deposited from the water column. Sediment n-alkane concentrations were similar at all depths of the cores when collected more than 125 m from the station. PAH levels in the sediment appeared to be due to local input, including a small spill in 1965.     

Benthic marine pollution around McMurdo Station, Antarctica: A summary of findings

McMurdo Station is the United States Antarctic Research Program's (USARP) centre for scientific and logistical support for most of the continent and is the largest settlement in Antarctica. Over 30 years of human presence with shipping, air-transport, scientific, and municipal activities have resulted in severe but localized nearshore marine benthic pollution. This review will summarize the results of 3 years of research which has documented concentrations of chemical contaminants, changes in community patterns, and the toxicity of sediments to invertebrate species and infaunal communities. The primary contaminants are petroleum hydrocarbons in the sediments of Winter Quarters Bay, the site of shipping activities and a former dumpsite. Total hydrocarbon levels in sediments in Winter Quarters Bay were comparable to the most polluted harbours in temperate latitudes. However, a steep gradient of pollution existed: stations less than 1 km away were nearly pristine. Benthic invertebrate communities changed dramatically along this contamination gradient. The results of both field and laboratory bioassay experiments with contaminated sediments found that biological changes observed in benthic communities around McMurdo Station were most likely caused by hydrocarbons, PCBs, and PCTs. A primary goal of polar pollution research is to determine the response and tolerance of Antarctic biota to physical and chemical anthropogenic disturbance, and the mitigation of negative effects. To this end, future work should include continued monitoring of changes in chemical and community patterns, studies of the physiological responses of Antarctic invertebrates to chemical contamination, and further comparisons of anthropogenic and natural disturbances to benthic communities.     

Aliphatic and aromatic hydrocarbons in benthic invertebrates from two sites in Antarctica

Samples of marine benthic invertebrates collected from two sites in the Antarctic have been analysed for both aliphatic and aromatic hydrocarbons in order to establish baseline concentrations for some classes of hydrocarbons.Samples from Signy Island, a pristine site, contained low concentrations of the hydrocarbons determined, whereas those from King Edward Cove, South Georgia, contained significantly higher concentrations. King Edward Cove has a known history of pollution from whaling operations.Platt & Mackie (1979) have suggested that the hydrocarbons in sediments from King Edward Cove are a result of the world-wide dissemination of the pyrolysis products of fossil fuels. Our work suggests, in contrast, that the hydrocarbons in the benthos are derived from local sources.     

Survey of tar,hydrocarbon and metal pollution in the coastal waters of Oman

Quantitative beach sampling conducted after the S. W. monsoon season yielded average standing stocks of tar ranging from 5 to 2325 g m^?1 of shoreline with overall average of 224 g m^?1. Values are among the highest reported for any world area and show a trend of increasing levels of oil residues close to the Strait of Hormuz. Data support the premise that tanker deballasting is a major source of oil pollution on the Omani coast. Locally high levels were seen near offshore tanker loading facilities. Petroleum hydrocarbons in rock oysters increased in a south to north gradient consistent with beach tar observations. But relatively low hydrocarbon levels in biota coupled with observations of very little floating tar suggests that oil released in Omani coastal waters aggregates, sinks, and reaches the coast as heavy tar lumps. Except for elevated levels of Cd at two stations, heavy metal and chlorinated hydrocarbon concentrations were low compared to more industrialized world areas. Suggestions are made to improve the effectiveness of future pollution studies in the Gulf Region.     

Hydrocarbon and coprostanol levels in seawater, sea-ice algae and sediments near Davis station in eastern Antarctica: A regional survey and preliminary results for a field fuel spill experiment

A survey of hydrocarbons and the sterol coprostanol, together with a hydrocarbon degradation experiment, was conducted in a coastal marine environment in East Antarctica. Aliphatic hydrocarbon levels in sea-ice algae were 1.9–12.5 mg m⁻² and in seawater particulate matter 0.07–0.17 μg l⁻¹. Sea-ice algae contained the diatom biomarker, the highly branched isoprenoid (ip) diene ipC_25:2, and Southern Ocean seawater particulate matter samples were distinguished from near shore samples by the presence of nC_21:6. Sea-ice algae and seawater particulate matter samples showed a predominance of even chain n-alkanes. Hydrocarbon levels in sediment samples from anoxic fjord basins were high (45–48 μg g⁻¹) compared to a sub-tidal marine sample (0.7 μg g⁻¹), and were predominantly of bacterial origin. Contaminants detected were linear alkyl benzenes in sewage effluent from Davis station, and polycyclic aromatic hydrocarbons (PAH) which were present in very low levels (parts per trillion) throughout the environment. High levels of 2,6-dimethylnaphthalene were found in anoxic sediment from Ellis Fjord and may arise from a novel bacterial source. Coprostanol concentrations in sediments ranged from 67 to 1280 ng g⁻¹. A dual origin is proposed from marine mammalian faeces and, at several sites, from conversion of algal-derived sterols by anaerobic bacteria. Future studies examining the impact of human sewage from scientific bases or other ventures should use care in interpreting results when such high baseline values, from marine mammalian input, may occur naturally around the Antarctic coast. The potential exists, however, for the technique to distinguish between human and mammalian inputs through measurement of the coprostanol to epicoprostanol ratio, particularly if undertaken with appropriate comparative sampling. Results for a hydrocarbon degradation experiment where a light fuel was applied to an Antarctic beach, showed loss of up to 99% of the fuel within 2 months, mainly by volatilization.     

An Assessment of Potential Oil Spill Damage to Salt Marsh Habitats and Fishery Resources in Galveston Bay, Texas

We sampled nekton, benthic infauna, and sediments in salt marshes of upper Galveston Bay, Texas to examine relationships between habitat use and sediment hydrocarbon concentration. Most marsh sediment samples were contaminated with relatively low concentrations of weathered petroleum hydrocarbons. We found few statistically significant negative relationships between animal density and hydrocarbon concentration (6 of 63 taxa examined using simple linear regression). Hydrocarbon concentration did not contribute significantly to Stepwise Multiple Regression models we used to explore potential relationships between animal densities and environmental parameters; in most cases where hydrocarbon concentration was an important variable in the models, the relationship was positive (i.e., animal densities increased with hydrocarbon concentration). Low hydrocarbon concentrations in sediments of upper Galveston Bay marshes could have contributed to our results either because levels were too low to be toxic or levels were toxic but too low to be detected by most organisms.     

Serpentinization,abiogenic organic compounds,and deep life

The hydrocarbons and other organic compounds generated through abiogenic or inorganic processes are closely related to two science subjects,i.e.,energy resources and life’s origin and evolution."The earth’s primordial abiogenic hydrocarbon theory"and"the serpentinization of abiogenic hydrocarbon theory"are the two mainstream theories in the field of related studies.Serpentinization generally occurs in slow expanding mid-ocean ridges and continental ophiolites tectonic environment,etc.The abiogenic hydrocarbons and other organic compounds formed through the serpentinization of ultramafic rocks provide energy and raw materials to support chemosynthetic microbial communities,which probably was the most important hydration reaction for the origin and early evolution of life.The superposition of biological and abiological processes creates big challenge to the identification of the abiogenic organic materials in serpentinite-hosted ecosystem.Whether abiotic(inorganic)process can form oil and gas resource is a difficult question that has been explored continuously by scientific community for more than a century but has not yet been solved.However,some important progress has been made.The prospecting practice of abiogenic hydrocarbons in commercial gases from the Songliao Basin,China,provides an important example for exploring abiogenic natural gas resources.     

Inputs and sources of hydrocarbons in sediments from Cienfuegos bay, Cuba

The spatial distribution of aliphatic and polycyclic aromatic hydrocarbons (PAHs) was investigated in sediments from the Cienfuegos bay. The highest anthropogenic hydrocarbon inputs were found near the city of Cienfuegos with an unresolved complex mixture (UCM) of aliphatic hydrocarbons and alkylated PAHs, indicative of petrogenic inputs. Parent PAHs, which are typical of high-temperature combustion processes, were evenly distributed in the whole basin and largely prevailing in the southern part of the Cienfuegos city. Biomarker fingerprints assign the sources of pollution to mixes of national and non-national crude oils. The overall levels of anthropogenic hydrocarbons are relatively high compared to relevant areas worldwide and reveal a moderate/high level of hydrocarbon pollution. The Cienfuegos bay sediments received over a period of 5 yr, 50 T/yr of petrogenic unresolved hydrocarbons (UCM) and 2 T/yr of PAHs, being deposited the 80% in the sediments of the north basin.     

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.     

Uptake and discharge of petroleum hydrocarbons by barnacles

The hydrocarbon content of barnacles living on tarballs has been compared with the hydrocarbon composition of the tarballs. While there is some contamination of the barnacles there is no evidence of gross pollution and the analyses suggest that oil hydrocarbons are assimilated and then discharged, unmetabolized, quite rapidly.     

Aerial flux of particulate hydrocarbons to the Chesapeake Bay Estuary

Bulk hydrocarbon deposition rates have been measured over a 15 month period at four stations in south-eastern Virginia surrounding the lower Chesapeake Bay. A nearly linear trend of atmospheric particulate deposition was recorded. Deposition rates at the urban station (195 μg m^?2 day^?1) were aproximately three times greater than those recorded for nonurban and coastal locations (mean value 69 μg m^?2 day^?1). The increased levels at the urban location were attributed to localized source inputs. Anthropogenic hydrocarbons accounted for approximately 50% of the total deposition at all stations. Significant biogenic inputs were indicated by the odd/even n-alkane distribution. A minimum flux to the water surface, based on mean nonurban deposition rates (24 mg yr^?1), indicated an annual particulate hydrocarbon flux of +275 metric tons. Little information is available for the comparison of additional source inputs; however, the data reported here indicate that the aerial deposition of hydrocarbons is of the same order of magnitude as the input from municipal wastewater facilities and accidental discharge and is a potentially significant source of hydrocarbon pollution to the Chesapeake Bay Estuary.     

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.     

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.     

Impacts of pollution on coastal and marine ecosystems including coastal and marine fisheries and approach for management: a review and synthesis

The history of aquatic environmental pollution goes back to the very beginning of the history of human civilization. However, aquatic pollution did not receive much attention until a threshold level was reached with adverse consequences on the ecosystems and organisms. Aquatic pollution has become a global concern, but even so, most developing nations are still producing huge pollution loads and the trends are expected to increase. Knowledge of the pollution sources and impacts on ecosystems is important not only for a better understanding on the ecosystem responses to pollutants but also to formulate prevention measures. Many of the sources of aquatic pollutions are generally well known and huge effort has been devoted to the issue. However, new concepts and ideas on environmental pollution are emerging (e.g., biological pollution) with a corresponding need for an update of the knowledge. The present paper attempts to provide an easy-to-follow depiction on the various forms of aquatic pollutions and their impacts on the ecosystem and organisms.     

Isolation and characterization of two crude oil-degrading yeast strains, Yarrowia lipolytica PG-20 and PG-32, from the Persian Gulf

Among six crude oil-degrading yeasts that were isolated from an oil-polluted area in the Persian Gulf, two yeast strains showed high degradation activity of aliphatic hydrocarbons. From an analysis of 18S rRNA sequences and biochemical characteristics, these strains were identified as Yarrowia lipolytica strains PG-20 and PG-32. Gas Chromatography (GC) analysis of the crude oil remaining in the culture medium after 1 week at 30°C showed that the strains PG-20 and PG-32 degraded 68% and 58% of crude oil, respectively. The optimal growth condition and biodegradation of hydrocarbons was in ONR medium with an acidic pH (pH5). These two strains may degrade aliphatic hydrocarbons more efficiently than aromatic hydrocarbons, although strain PG-20 had better degradation than strain PG-32. The two Y. lipolytica strains reduce surface tension when cultured on hydrocarbon substrates (1% v/v). These strains showed a cell surface hydrophobicity higher than 70%. These results suggested that Y. lipolytica strains PG-20 and PG-32 have high crude oil degrading activity due to their high emulsifying activity and cell hydrophobicity. In conclusion, these yeast strains can be useful for the bioremediation process in the Persian Gulf and decreasing oil pollution in this marine ecosystem.     

Anthropogenic and Natural Components of Hydrocarbons in the Water of Lake Nero in Yaroslavl Oblast

The results of studies of spatial and seasonal variations in hydrocarbon concentrations in hypertrophic Lake Nero are used to discuss the problem of division of hydrocarbons into anthropogenic and natural components. It is shown that the use of bitumoids as a component of oil pollution instead of total organic matter can introduce errors in the results. Seasonal variations in the activity of hydrobionts in an undisturbed area are shown to have a notable effect on the assessment of the proportion of anthropogenic hydrocarbons in their total concentration, that is, on the assessment of the extent of pollution of water bodies. The natural component is found to dominate over the anthropogenic component only in the periods of algae blooming. In spring and autumn, the total concentration of hydrocarbons was found to exceed the MAC and to be due mostly to natural hydrobiological factors.     

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.     

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.     

Petrowatch: Petroleum hydrocarbons,synthetic organic compounds,and heavy metals in mussels from the Monterey Bay area of central California

Mussel Watch techniques were used to measure the concentrations of petroleum hydrocarbons, synthetic organic hydrocarbons, and trace metals in a preliminary study of the Monterey Bay area in central California. Resident mussels were found to have higher-than-expected petroleum hydrocarbon body burdens in Carmel Bay, an area thought to be relatively contaminant free. A ‘hot spot’ of PCB 1254 and pp′DDE was measured at Año Nueuvo Island, a site previously recognized because of elevated levels of mercury in mussels. PCB 1254 concentrations at Año Nuevo Island were high in relation to the remainder of coastal United States and Baja California, reflecting entrainment of this compound at a biologically active area. The Monterey Harbor Jetty location showed the highest contamination levels for zinc and lead. In fact, this location has the second highest lead concentrations in mussels for the California coast. Biological cycling of certain compounds (PCB, DDT and mercury) in remote locations such as Año Nuevo Island, is hypothesized as a mechanism for these elevated concentrations in mussels. Levels of other synthetic organic hydrocarbons were generally low, with chlordanes showing higher concentrations in the more urbanized locations of the study area, i.e. the Monterey Harbor Jetty.