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.     

Bioremediation of petroleum hydrocarbons in anoxic marine sediments: Consequences on the speciation of heavy metals

We investigated the effects of biostimulation and bioagumentation strategies applied to harbor sediments displaying reducing conditions and high concentrations of petroleum hydrocarbons and heavy metals. We compared the microbial efficiency of hydrocarbon removal from sediments maintained for 60 days in anoxic conditions and inoculated with acetate, sulfate-reducing bacterial strains and acetate and sulfate-reducing bacteria. All treatments determined a significant increase in the microbial growth and significant decreases of hydrocarbon contents and of redox potential values. The addition of sulfate-reducing bacterial strains to the sediment was the most efficient treatment for the hydrocarbon removal. In all experiments, significant changes of the heavy metals’ phase repartition were observed. The results reported here suggest that the biodegradation of petroleum hydrocarbons in anoxic marine sediments may be enhanced by stimulating microbial anaerobic metabolism, but care should be applied to monitor the potential changes in the mobility and bioavailability of heavy metals induced by bio-treatments.     

Bioconcentration factors for petroleum hydrocarbons, PAHs, LABs and biogenic hydrocarbons in the blue mussel

Bioconcentration factors (K_bc) for petroleum hydrocarbons, PAHs, LABs and biogenic hydrocarbons in Mytilus edulis were measured in field experiments using time-integrating water samplers. Seven deployments at five sites gave lipid weight K_bcs for total hydrocarbons ranging from 0.99 × 10⁶ to 3.1 × 10⁶ (mean 1.6 × 10⁶)—a narrower range than has been obtained previously. Bioconcentration factors for the PAHs were similar to those for total hydrocarbons where the major hydrocarbon source was oil. However, at other sites the factors for PAHs were an order of magnitude lower than those for petroleum and for hydrocarbons originating from algae. Compositional profiles for the linear alkyl benzenes (LABs) suggested that these compounds were assimilated primarily from the dissolved phase, despite their greater abundance on particles.     

Distribution of petroleum hydrocarbons and organochlorinated contaminants in marine biota and coastal sediments from the ROPME Sea Area during 2005

The composition and spatial distribution of various petroleum hydrocarbons (PHs), comprising both aliphatic and polycyclic aromatic hydrocarbons (PAHs), and selected chlorinated pesticides and PCBs were measured in biota and coastal sediments from seven countries in the Persian Gulf and the Gulf of Oman (Bahrain, Iran, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates). Evidence of extensive marine contamination with respect to organochlorinated compounds and PHs was not observed. Only one site, namely the BAPCO oil refinery in Bahrain, was considered to be chronically contaminated. Comparison of the results from this survey for Σ DDTs and Σ PCBs in rock oysters from the Gulf of Oman with similar measurements made at the same locations over the past two decades indicates a temporal trend of overall decreasing Σ PCB concentrations in oysters, whereas Σ DDTs levels have little changed during that period.     

Total petroleum hydrocarbons and heavy metals in the surface sediments of Bohai Bay,China: Long-term variations in pollution status and adverse biological risk

Surface sediments collected from 2001 to 2011 were analyzed for total petroleum hydrocarbons (TPH) and five heavy metals. The sediment concentration ranges of TPH, Zn, Cu, Pb, Cd and Hg were 6.3–535 μg/g, 58–332 μg/g, 7.2–63 μg/g, 4.3–138 μg/g, 0–0.98 μg/g, and 0.10–0.68 μg/g, respectively. These results met the highest marine sediment quality standards in China, indicating that the sediment was fairly clean. However, based on the effects range-median (ERM) quotient method, the calculated values for all of the sampling sites were higher than 0.10, suggesting that there was a potential adverse biological risk in Bohai Bay. According to the calculated results, the biological risk decreased from 2001 to 2007 and increased afterwards. High-risk sites were mainly distributed along the coast. This study suggests that anthropogenic influences might be responsible for the potential risk of adverse biological effects from TPH and heavy metals in Bohai Bay.     

The 1974 spill of the Bouchard 65 oil barge: petroleum hydrocarbons persist in Winsor Cove salt marsh sediments

Petroleum hydrocarbons persist in salt marsh sediments in Winsor Cove (Buzzards Bay, Massachusetts) impacted from the 1974 spill of No. 2 fuel oil by the barge Bouchard 65. Intertidal sediment cores were collected from 2001 to 2005 and analyzed for total petroleum hydrocarbons (TPHs). TPHs content was greatest (as high as 8.7 mg g(-1) dry weight) in the surface sediments and decreased with distance landward. Select samples were analyzed for polycyclic aromatic hydrocarbons (PAHs) with values as high as 16.7 microg g(-1) for total naphthalenes and phenanthrenes/anthracenes. These remaining PAHs are mainly C(4)-naphthalenes and C(1)-, C(2)-, and C(3)-phenanthrenes/anthracenes revealing preferential loss of almost all of the naphthalenes and the parent compound phenanthrene. Inspection of the data indicates that biodegradation, water-washing and evaporation were major removal processes for many of the petroleum hydrocarbons in the marsh sediments. In addition, historical data and photographs combined with their recent counterparts indicate that erosion has physically removed these contaminants from this site.     

Degradation of hydrocarbons in oxidized and reduced sediments

The oxidation-reduction status of Gulf Coast wetland sediment greatly influenced hydrocarbon breakdown. Degradation of ¹⁴C-labelled octadecane and ¹⁴C-labelled naphthalene was faster in oxidized (+500 mV) sediment compared with reduced (?200 mV) sediment. Naphthalene showed no breakdown in reduced anaerobic sediment. However, a shift from strict anaerobic to aerobic conditions markedly increased napthalene degradation. An oxidized layer of sediment overlying reduced sediment was identified in several zones in a Louisiana salt marsh. Hydrocarbon degradation is likely to be greater in the oxidized surface layer.     

Spatial distribution and ecotoxicity of petroleum hydrocarbons in sediments from the Galicia continental shelf (NW Spain) after the Prestige oil spill

The distribution of aliphatic and aromatic hydrocarbons was determined in surface sediments collected at 36 stations along the Galicia continental shelf (NW Spain), following the Prestige oil spill. Sampling was performed in December 2002, just after the accident, and in February and September 2003. Concentrations of PAHs (summation operator 13 parent components) were in the range of 0.9-422 microg/kgdw, the highest values being close to coastal urban areas (e.g. Pontevedra and A Coru?a), whereas in the stations of the area most heavily impacted by the spill (off Costa da Morte) concentrations were in the range of 14.8-89.6 microg/kgdw, with a certain predominance of alkylated compounds, which may suggest a mixture of petrogenic and pyrolytic sources. The detailed study of petrogenic molecular markers (e.g. steranes and triterpanes) showed the occurrence of an old (weathered) petrogenic chronic pollution in the shelf sediments but not of the Prestige oil, with the possible exception of few stations in the area of Costa da Morte. This was attributed to the heavy nature of the spilled oil that was barely dispersed in the water column and mainly stranded on the coast or sedimented in the form of oil patches. The addition of increasing amounts of fuel oil to a representative sediment sample showed that the molecular indices were indicative of the presence of the Prestige oil when the amount was above 1g/kg of sediment. The toxicity of selected samples (showing the higher PAH concentrations) was tested using the bivalve embryogenesis bioassay. Embryogenesis success reached high values in all cases (80-88%, with 86% in the control), indicating a lack of toxicity in the sediments and supporting the conclusion that the patchiness of the fuel eventually reaching the seafloor reduced its impact on the benthic communities of the Galician shelf.     

Polycyclic aromatic hydrocarbons in the sediments of the Yalujiang Estuary,North China

Selected polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Yalujiang Estuary, North China, have been investigated by gas chromatography-mass spectrometry (GC-MS) for flood season (August, 1994) and dry season (May, 1996), respectively. PAHs concentrations from sediments range from 68 to 1500 ngg(-1) depending upon the sample locations. The most contaminated sediment samples are found in the turbidity maximum area for both dry and flood seasons. The source of PAHs is most likely pyrolytic, with minor contributions from petrogenic and diagenetic PAHs for some samples. Perylene is mainly derived from biogenic inputs, and occurs at almost stations. In the Yalujiang Estuary, both biogenic and anthropogenic hydrocarbons are primarily derived form riverine discharges and are accumulated in the mixing zone. The overall levels of PAHs in this study are low compared to other regions and reveal moderate PAHs pollution in the Yalujiang Estuary.     

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.     

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.     

Polycyclic aromatic hydrocarbons in sediments of the Great Barrier Reef region,Australia

At present the concentrations of polycyclic aromatic hydrocarbons in sediments from the Great Barrier Reef are remarkably low. The baseline levels range from <0.01 μg kg^?1 dry wt. for benzo(k)fluoranthene and benzo(a)pyrene to <0.82 μg kg^?1 for chrysene. Measurable levels of polycyclic aromatic hydrocarbons have only been found in small areas close to sites frequently visited by power boats. Sediments from Townsville and Gladstone Harbours on the coast adjacent to the reef are polluted with polycyclic aromatic hydrocarbons to a similar degree to that reported for coastal sediments in similar locations in other parts of the world.     

Chlorinated hydrocarbons in macroinvertebrates and fish from the Lower Medway Estuary,Kent

Macroinvertebrates and fish collected periodically from April 1973 to January 1976, from the Lower Medway Estuary, Kent, were analysed for a range of heavy metals, organochlorine pesticides and polychlorinated biphenyls. The heavy metal studies have been previously documented. Results of the chlorinated hydrocarbon analysis of mussels, shore crabs, periwinkles, ragworms, shrimps and selected fish tissues are presented and their significance discussed.     

Pelagic tar, dissolved/dispersed petroleum hydrocarbons and plastic distribution in the Cretan Sea, Greece

During the first cruise of R/V ‘Philia’ in July 1997 within the framework of the TALOS programme supported by the Greek Ministry of Physical Planning and Public Works, the sampling of floating tar, litter and sea water for dissolved/dispersed petroleum hydrocarbons (DDPH) was carried out in the Cretan Sea. Analysis of these data has allowed a first assessment of the status of floating marine pollution in the region. DDPH measurements showed a mean concentration of 0.145 μg/l of chrysene equivalents (n = 24). Tar and plastics concentrations were in the range of 1–4280 and 0–1160 μg/m², respectively. Mean pelagic tar concentration was 318 μg/m², more than two times higher than what was reported for the area in previous studies. Based on in situ hydrographic observations there is strong evidence that most of the floating tar enters the Cretan Sea through the Ionian Sea.     

Dissolved petroleum hydrocarbons in some regions of the northern Indian ocean

Dissolved petroleum hydrocarbons were measured in some parts of the Northern Indian Ocean using UV absorbance technique with a clean up step. The concentration of oil ranged from 0.6 to 26.5 μg l^?1. Higher values were recorded along the oil tanker route compared with the coastal region From surface to about 10 m depth the oil appeared to be well mixed with water.     

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.