The ecological,chemical and histopathological evaluation of an oil spill site: Part III. Histopathological Studies

In July 1971 when approximately 25% of the clams in Long Cove, Searsport, Maine, had been killed by the March 1971 oil spill, collections of surviving clams for histological examination were made. These studies were continued through 1974 and revealed a high incidence of gonadal tumours in clams contaminated by the oil. The area of highest oil impact correlated with the highest per cent of tumours. The tumours were found to be malignant neoplasms.     

The ecological,chemical and histopathological evaluation of an oil spill site: Part II. Chemical Studies

The oil from the March 1971 spill in Long Cove, Searsport, Maine, was identified with the aid of adjacent shoreline tank farm samples to be No. 2 fuel oil mixed with JP5 jet fuel. Sediment samples obtained from animal collection sites were analyzed by gas chromatographic procedures and were found to contain significant quantities of petroleum hydrocarbons.     

Size-selective mortalities of clams in an oil spill site

Mixed No. 2 fuel oil and JP5 jet fuel, following an oil spill into Long Cove, Searsport, Maine, U.S.A., in March 1971 became concentrated locally at levels up to more than 250 ppm in intertidal sediments from 15 to 25 cm below the surface and continued until 1976 to kill successive year class juvenile clams as in normal growth behaviour they burrowed down through redistributed overlying clean sediments into the oil concentration beneath.     

Reduced growth and survival of clams transplanted to an oil spill site

Production of soft clams fell by 20% in two years following oil pollution although in adjacent mudflats production of them increased by 250%. Transplanting uncontaminated clams into this area confirmed poorer survival and slower growth in polluted mud.     

The Eleni V oil spill: Fate and effects of the oil over the first twelve months: Part I. Oil in Waters and Sediments

The fate and effects of the spill of Eleni V heavy fuel oil in May 1978 have been followed at two sites; one a heavily-polluted area subject to mechanical clean-up and one an undisturbed site where oil remains. At the first site the mechanized clean-up, and re-sorting of beach material by winter storms, has left the area visually clean of oil. However, near-shore and interstitial waters still contain high concentrations of Eleni V hydrocarbons 12 months after the spill. At the undisturbed site there has been very little change in the appearance and chemical composition of the oil during this period.     

The Eleni V oil spill: Fate and effects of the oil over the first twelve months: Part II. Biological effects

The general effects of the Eleni V oil spill on fisheries and intertidal organisms are described. There appears to have been little damage except by direct smothering. Oil hydrocarbon concentrations have been followed in a small intertidal population of mussels (Mytilus edulis) at Corton beach. Although the area became visually clean of oil, hydrocarbon concentrations in mussel flesh remained high 12 months after the spill and depuration rates in the laboratory were very slow. Shrimps (Crangon crangon) exposed to a water extract of beached Eleni V oil for 42 days showed no ill effects and little uptake of hydrocarbons. At the North Harbour site, where beached oil has not been disturbed, it appears that the fauna, used to oil contamination from other sources, has been little affected by the additional Eleni V oil.     

The formulation of an effective demulsifier for oil spill emulsions

The formation of stable sea water-in-crude oil emulsions after an oil spill was first reported after the Torrey Canyon wreck in 1967. The problem of handling this stable water (65%)-in-oil (35%) emulsion rather than oil is evidenced in the additional expensive on-site storage requirement as well as the handling difficulty with the viscous semi-solid emulsion. This paper details the results of an R&D program that has established the mechanism for the formation of this emulsion. This insight enabled a specific effective chemical demulsifier to be formulated. A treatment technique was devised that entails injecting the demulsifier into the oil spill emulsion as it is skimmed from the water surface. The emulsion is then rapidly separated into water-free oil and a clean-water phase that can be decanted back into the sea. Full-scale tests were successfully conducted by JBF Scientific Corp. using two types of commercial JBF DIP skimmers in a small concrete lined pond.     

Relationship between soil cellulose decomposition and oil contamination after an oil spill at Swanson Creek, Maryland

In wetlands, oil spills may affect decomposition in soils, which controls organic matter accumulation, the primary contributor to positive elevation change. In this study we examined how oil from a spill affected organic matter decomposition in soils of a brackish intertidal marsh in Maryland. Decomposition was measured using the cellulose (cotton) strip technique. Cellulose decomposition was not affected by concentrations of different oil components (total hydrocarbons, total resolved hydrocarbons, and polycyclic aromatic hydrocarbons). Rather, other abiotic characteristics of the soil had strong effects on decomposition rates, including strong negative effects of soil depth and salinity, and a positive effect of pH. Measures of soil fertility (NH(4)-N and PO(4)-P) were not significantly related to cellulose decomposition. Thus, we conclude that decomposition was controlled more by naturally occurring environmental factors rather than by exposure to oil.     

Effects of three oil spill dispersants on marine bacterial populations: I. Preliminary Study. Quantitative Evolution of Aerobes

The effects of three hydrocarbon dispersant agents (Corexit 9527, Hydrogamosol LT and OSR LT 126) on the bacterial flora of the marine environment are analysed in 20-square-metre basins filled with lagoon seawater.Four months after the first treatment, oil slicks were no longer visible, whereas the appearance of the untreated reference slick had hardly changed. The treatment of 10-litre crude-oil slicks causes an appreciable and long lasting increase in the bacterial population.     

Sediment hydrocarbon contamination at the site of the Baie Verte,Newfoundland, oil spill: Results of a Four Year Study

Sediments samples were taken at 3, 15, 27, and 39 months following a spill of diesel oil at Baie Verte, Newfoundland, to determine the effects of weathering on diesel oil trapped in the sediments and to attempt to develop a suitable method for extraction and analysis.Extraction was carried out using hexane, concentration was effected by a procedure modified from Junk et al. (1974) and analysis was completed within 18.0 min by high performance liquid chromatography (HPLC) using a bonded amino silane-(NH₂) column (5 μm, 5 mm × 25 cm) with hexane as mobile phase. A backflush cycle of 22.0 min using hexane and methl-t-butyl ether (90:10%) was performed to elute any polar compounds from the column.This class analysis by HPLC indicated a decrease in the amount of naphthalene, fluorene, phenanthrene and benzo[a]pyrene equivalents over time and at the conclusion of the study (39 months) no PAHs except for fluorene were found in the sediments from Baie Verte.     

The Eurobulker oil spill: mid-term changes of some ecosystem indicators

The sinking of the tanker Eurobulker in Southern Evoikos gulf (Aegean Sea, Greece) in September 2000 resulted in a spill of 700 tons of crude oil. The environmental impact of the spill was studied by the National Centre for Marine Research. The hydrocarbon concentrations in water, sediment and coastal benthic organisms were measured and the response of the benthic communities to the disturbance caused by the oil spill was studied along the direction to the coast and over three sampling seasons. The most severe and direct effects were evidenced on the muddy benthic communities of the accident site and the stations in the close vicinity sampled shortly after the spill. The effects included reduction of the species richness and community diversity, but the communities reached full recovery 8 months later. The impact of the spill was more indirect and delayed in the coastal stations, where as the hydrocarbon measurements indicated, the pollutants were transported later and induced their effects on the benthic communities 6 months after the accident.     

Hebei Spirit oil spill monitored on site by fluorometric detection of residual oil in coastal waters off Taean, Korea

The spatiotemporal distributions of dissolved and/or dispersed oil in seawater and pore water were monitored on site by fluorometric detection method after the Hebei Spirit oil spill. The oil concentrations in intertidal seawater, 15 days after the spill, were as high as 16,600 μg/L and appeared to decrease below the Korean marine water quality standard of 10 μg/L at most sites 10 months after the spill. Fluorometric detection of oil in pore water was introduced to eliminate the effects of grain size for the quantification of oil in sediments and to better explain spatial and temporal distribution of oil pollution at sandy beaches. The fluorescence detection method was compared with the conventional laboratory technique of total petroleum hydrocarbon analysis using gas chromatography. The method of fluorescence detection of oil was capable of generating results much faster and more cost-effectively than the traditional GC technique.     

The aegean sea oil spill in the Galicia Coast (NW Spain). I. Distribution and fate of the crude oil and combustion products in subtidal sediments.

The spatial distribution and fate of petrogenic and pyrogenic hydrocarbons in coastal sediments following the Aegean Sea oil spill (Galicia, NW Spain) was investigated through a detailed study of chemical markers. Alkanes and acyclic isoprenoid hydrocarbons were degraded within six months of the accident, but triterpane and sterane distributions were still detectable and were useful in monitoring, respectively, the oil source and weathering. Aromatic steranes were also useful source indicators, and oil degradation was clear from the decrease of certain alkyl dibenzothiophene and phenanthrene isomers. The pyrogenic polycyclic aromatic hydrocarbons produced in the tanker wreck were found more persistent than the petrogenic ones. However, the presence of the oil in the sediments was recognized even one year after the accident and was found particularly preserved in the subsurface layers.     

SAR observation and model tracking of an oil spill event in coastal waters

Oil spills are a major contributor to marine pollution. The objective of this work is to simulate the oil spill trajectory of oil released from a pipeline leaking in the Gulf of Mexico with the GNOME (General NOAA Operational Modeling Environment) model. The model was developed by NOAA (National Oceanic and Atmospheric Administration) to investigate the effects of different pollutants and environmental conditions on trajectory results. Also, a Texture-Classifying Neural Network Algorithm (TCNNA) was used to delineate ocean oil slicks from synthetic aperture radar (SAR) observations. During the simulation, ocean currents from NCOM (Navy Coastal Ocean Model) outputs and surface wind data measured by an NDBC (National Data Buoy Center) buoy are used to drive the GNOME model. The results show good agreement between the simulated trajectory of the oil spill and synchronous observations from the European ENVISAT ASAR (Advanced Synthetic Aperture Radar) and the Japanese ALOS (Advanced Land Observing Satellite) PALSAR (Phased Array L-band Synthetic Aperture Radar) images. Based on experience with past marine oil spills, about 63.0% of the oil will float and 18.5% of the oil will evaporate and disperse. In addition, the effects from uncertainty of ocean currents and the diffusion coefficient on the trajectory results are also studied.     

The West Falmouth oil spill after 20 years: Fate of fuel oil compounds and effects on animals

The barge Florida spilled No. 2 fuel oil into Buzzards Bay, Massachusetts on 29 September 1969. Sediments from five of the original stations were sampled in August 1989 and analysed for fuel oil hydrocarbons. Two subtidal and one intertidal marsh station showed no evidence of fuel oil. One subtidal mud core had traces of biodegraded fuel oil at 10–15 cm. One marsh core contained 10⁻⁶ g g⁻¹ dry wt of weathered and biodegraded fuel oil aromatic hydrocarbons and cycloalkanes at 5–10 cm with lesser concentrations at 0–5 and 10–15 cm. Although present in trace concentrations, these hydrocarbons appear to be slightly inducing cytochrome P4501A in marsh fish (Fundulus heteroclitus).     

An evaluation of marine bird population trends following the Exxon Valdez oil spill, Prince William Sound, Alaska

We examined post-spill trends (1989-1998) of marine bird populations in Prince William Sound (PWS) following the Exxon Valdez oil spill (EVOS) to evaluate recovery of injured taxa. Two criteria were employed. First, we examined population trends of injured taxa only in the oiled area of PWS using regression models. Second, we examined population trends of injured taxa in the oiled area relative to the unoiled area using homogeneity of the slopes tests. We considered a population recovering if there was a positive trend using either criteria. We considered a population not recovering if there was no trend using either criteria or a negative trend in the oiled area. A significant negative trend in the oiled area relative to the unoiled area was considered a continuing and increasing effect. Most taxa for which injury was previously demonstrated were not recovering and some taxa showed evidence of increasing effects nine years after the oil spill. Four taxa (loons Gavia spp, Harlequin Duck Histrionicus histrionicus, Bufflehead Bucephala spp, and North-western Crow Corvus caurinus) showed weak to very weak evidence of recovery. None of these taxa showed positive trends in both winter and summer. Nine taxa (grebes Podiceps spp, cormorants Phalacrocorax spp, Black Oystercatcher Haematopus bachmani, Mew Gull Larus canus, Glaucous-winged Gull Larus glaucescens, terns Sterna spp, murres Uria spp, Pigeon Guillemot Cepphus columba, and murrelets Brachyramphus spp) showed no evidence of recovery during summer or winter. Four taxa (scoters Melanitta spp, mergansers Mergus spp, goldeneyes Bucephala spp, and Black-legged Kittiwaka Rissa tridactyla) showed evidence of continuing, increasing effects. We showed evidence of slow recovery, lack of recovery, and divergent population trends in many taxa which utilize shoreline and nearshore habitats where oil is likely to persist. Potential lingering spill effects and natural variability appear to be acting in concert in delaying recovery of many PWS bird populations.     

Weathering of an Arctic oil spill over 20 years: the BIOS experiment revisited. Baffin Island Oil Spill

A small experimental oil spill was conducted on the northern tip of Baffin Island Nunavut, Canada (72 degrees 31' N, 79 degrees 50' W) in August 1981, and the natural weathering of the oil has been followed by periodic visits. This paper reports on the chemical composition of oil collected in August 2001. The vast majority of the initial oil has gone, but small patches remain. Some samples remain essentially unaltered despite their 20 years of exposure to the elements, while others show that biodegradation and photooxidation can play important roles in removing the majority of the components of the oil. Using 17alpha(H)21beta(H)hopane as a conserved marker within the oil, we show that the most biodegraded sample has lost more than 87% of the hydrocarbons initially present, while another has lost a substantial proportion of its initial chrysene and alkylated congeners. Potential explanations for the different weathering patterns seen in samples collected from this small site are briefly discussed.     

The state of a river in pechora basin after an oil spill: Assessment of changes in zooplankton community

The long-term dynamics of zooplankton in a northern river has been studied in the context of its pollution after an oil pipeline break. Oil has been shown to have both negative and stimulating effect on planktonic communities and populations, and the role of the drainage area in river system self-purification is studied. Artificial settling water bodies, which had been formed by regulation of polluted flows in the river, have been found to have additional significance as biological regenerators of aquatic ecosystems.