Crude Oil Pollution Research Articles

Optoacoustic Sensing of Surfactant Crude Oil in Thermal Relaxation and Nonlinear Regimes.

We propose a laser optoacoustic method for the complex characterization of crude oil pollution of the water surface by the thickness of the layer, the speed of sound, the coefficient of optical absorption, and the temperature dependence of the Grüneisen parameter. Using a 532 nm pulsed laser and a 1–100 MHz ultra-wideband ultrasonic antenna, we have demonstrated the capability of accurate (>95%) optoacoustic thickness measurements in the 5 to 500-micron range, covering 88% of slicks observed during 2010 oil spill in the Gulf of Mexico. In the thermal relaxation regime of optoacoustic measurements, the value of optical absorption coefficient (30 mm−1) agreed with the data of independent spectrophotometric measurements, while the sound speed (1430 m/s) agreed with the tabular data. When operating in a nonlinear regime, the effect of local deformation of the surface of the oil film induced by heating laser radiation was revealed. The dose-time parameters of laser radiation ensuring the transition from the thermal relaxation regime of optoacoustic generation to nonlinear one were experimentally investigated. The developed OA method has potential for quantitative characterization of not only the volume, but also the degree and even the type of oil pollution of the water surface.

Effects of crude oil pollution on soil moisture infiltration with loessial soil and aeolian sandy soil

Crude oil may block soil pores, affect soil water repellency, and change soil water movement. In this study, soil column simulation was used to study the effects of different crude oil pollution levels (0, 0.5%, 1%, 2%, 4%) on the water infiltration processes in loessial soil and aeolian sandy soil. The results showed that soil wetting front speed and infiltration rate of those two soils decreased with increasing crude oil content. The time needed for wetting front reaching the bottom of the soil column was the longest under 4% crude oil polluted soil, which was 4 times and 48 times longer than that of no crude oil polluted soil for loessial soil and aeolian sandy soil, respectively. The cumulative infiltration of loessial soil decreased with increasing crude oil content, while it increased to the max and then decreased as the crude oil content increased in aeolian sandy soil. The cumulative infiltration curves of aeolian sandy soil with high crude oil contents (2% and 4%) presented "up-tail" phenomenon. Kostiakov infiltration model and Philip infiltration model could better fit the infiltration process than Green-Ampt model for loessial soil with different crude oil content. However, the two models could only well fit the infiltration process for aeolian sandy soil with low crude oil content (0, 0.5%, 1%). Crude oil pollution could significantly affect soil water infiltration process, especiall in aeolian sandy soil.

Bioremediation treatment improves water quality for Nile tilapia ("{"Oreochromis niloticus"}") under crude oil pollution

BACKGROUND AND AIM: Despite favorable publicity of bioremediation as an affordable technology for cleanup of crude oil, public concerns on ecological safety in the presence of residual oil remain a global challenge. In this study, effects of crude oil exposure at sublethal concentration (0.25% v/v) and bioremediation treatment were investigated on histology and biochemical parameters of organs (gills, liver, kidney, and brain) of juvenile Nile tilapia (

Simulated Ageing of Crude Oil and Advanced Oxidation Processes for Water Remediation since Crude Oil Pollution

Crude oil can undergo biotic and abiotic transformation processes in the environment. This article deals with the fate of an Italian crude oil under simulated solar irradiation to understand (i) the modification induced on its composition by artificial ageing and (ii) the transformations arising from different advanced oxidation processes (AOPs) applied as oil-polluted water remediation methods. The AOPs adopted were photocatalysis, sonolysis and, simultaneously, photocatalysis and sonolysis (sonophotocatalysis). Crude oil and its water-soluble fractions underwent analysis using GC-MS, liquid-state 1H-NMR, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and fluorescence. The crude oil after light irradiation showed (i) significant modifications induced by the artificial ageing on its composition and (ii) the formation of potentially toxic substances. The treatment produced oil oxidation with a particular effect of double bonds oxygenation. Non-polar compounds present in the water-soluble oil fraction showed a strong presence of branched alkanes and a good amount of linear and aromatic alkanes. All remediation methods utilised generated an increase of C5 class and a decrease of C6–C9 types of compounds. The analysis of polar molecules elucidated that oxygenated compounds underwent a slight reduction after photocatalysis and a sharp decline after sonophotocatalytic degradation. Significant modifications did not occur by sonolysis.

Influence of crude oil pollution on the content and electrophoretic spectrum of proteins in Carex hirta plants at the initial stages of vegetative development

The role of proteins in the general adaptive response of Carex hirta plants to soil pollution by crude oil has been studied. It was established that a possible element of the process of adaptation of C. hirta plants to combined stress – conditions of soil polluted by crude oil – may be the synthesis of stress proteins – high molecular weight of more than 60 kD and low molecular weight, not exceeding 22–45 kD. The synthesis of all 5 HSP families was detected in the leaves and rhizomes, and only sHSP (starting from Mr 32 kD), Hsp 60 and Hsp 100 proteins were synthesized in the roots under the influence of crude oil pollution. The development of C. hirta adaptation syndrome under the influence of crude oil pollution of the soil was promoted by enhanced synthesis of proteins with Mr 85, 77, 64, 60 and 27 kD in the leaves, 118 and 41 kD in the rhizomes and proteins with Mr 105, 53, 50 and 43 kD in the roots of the plants. The decrease in the amount of proteins with Mr 91, 45, 28 kD in the leaves, proteins with Mr 85, 76 and 23 kD in rhizomes and proteins with Mr 64 and 39 in the roots of C. hirta plants under conditions of crude oil polluted soil could be a consequence of inhibition of synthesis or degradation of protein molecules providing the required level of low molecular weight protective compounds in cells. The root system and rhizomes of C. hirta plants undergo a greater crude oil load, which leads to increased protein synthesis in these organs and decreased in the leaves, correspondingly. However, a decrease in protein content in the leaves may indicate their outflow in the roots and rhizomes. Сrude oil contaminated soil as a polycomponent stressor accelerated the aging of leaves of C. hirta plants, which could be caused by increased synthesis of ABA. ABA in its turn induced the synthesis of leaf-specific protein with Mr 27 kD. These proteins bind significant amounts of water with their hydrate shells maintaining the high water holding capacity of the cytoplasm under drought conditions. ABA inhibits the mRNA synthesis and their corresponding proteins, which are characteristic under normal conditions, and induces the expression of genes and, consequently, the synthesis of specific proteins including 27 kD protein. By stimulating the expression of individual genes and the synthesis of new polypeptides, ABA promotes the formation of protective reactions and increases the resistance of plants to crude oil pollution.

Pig (Sus scrofa domesticus) dung and their associated fungi: Potential candidates for bio-remediation and nutrients improvement of crude oil contaminated soils

Abstract. Enyiukwu DN, Bassey IN, Nwaogu GA, Asamudo NU, Chukwu LA, Monday EA, Maranzu JO. 2021. Pig (Sus scrofa domesticus) dung and their associated fungi: Potential candidates for bio-remediation and nutrients improvement of crude oil contaminated soils. Biodiversitas 22: 3276-3286. Pig dung a common agro-waste material in Nigeria is associated with many fungal saprophytes. Rising oil spillages and pollution in Nigeria have made cultivation of affected agro-lands un-rewarding. Potentials of pig dung in mitigating crude oil pollution in agro-soils are herein studied. The objectives of this study were to characterize the fungal profile associated with wet and dry dung of pig. And to evaluate the remediating impacts of pig dung and their associated fungi on crude oil and heavy metals contents, physicochemical properties, and phytotoxicity of crude oil polluted soils. Coprophilous fungi were isolated from wet and dry dung by moist chamber technique and identified. Utisoil from Umudike was polluted with crude oil, amended with 10-40% of dry pig dung and sown with soybean (Glycine max L.). The amended and un-amended crude oil contaminated utisols were analyzed to reduce crude oil and heavy metals contents; and physicochemical properties at planting, and harvesting, respectively, using classical and spectrometric methods, and the extent of crude oil and heavy metals removal determined. The percentage germination, height, number of leaves, leaf color, vigor, and biomass of the test crop were recorded from the test plant. The results showed that Aspergillus candidus, Sclerotium sp., Absidia sp., Acremonium sp., Candida tropicalis, C. pseudotropicalis, and Rhizopus oryzae were consistently isolated from the dry dung specimen than the wet one. The results also indicated that the treatments significantly reduced the treated soils' crude oil and heavy metals contents. It revealed that values obtained for residual oil or heavy metals contents of the treated soils and crop performance were inversely and directly related to levels of soil amendment respectively. Crop performance in the amended soil remained statistically (P?0.05) higher compared to the control. Soil analyses showed that the dung treatments significantly increased the values of nitrogen, phosphorus, potassium, organic carbon, etc. in a directly proportional manner. Therefore, pig dung and their associated fungi hold strong potentials as cheap eco-friendly platforms to provide and stimulate microbial growth, hasten degradation and removal of crude oil and heavy metals from contaminated soils; and thus permit and sustain good performance of arable crops.

A novel approach for long-term spectral monitoring of desert shrubs affected by an oil spill

Crude oil pollution is a global environmental concern since it persists in the environment longer than most conventional carbon sources. In December 2014, the hyper-arid Evrona Nature Reserve, Israel, experienced large-scale contamination when crude oil spilled. The overarching goal of the study was to investigate the possible changes, caused by an accidental crude oil spill, in the leaf reflectance and biochemical composition of four natural habitat desert shrubs. The specific objectives were (1) to monitor the biochemical properties of dominant shrub species in the polluted and control areas; (2) to study the long-term consequences of the contamination; (3) to provide information that will assist in planning rehabilitation actions; and (4) to explore the feasibility of vegetation indices (VIs), along with the machine learning (ML) technique, for detecting stressed shrubs based on the full spectral range. Four measurement campaigns were conducted in 2018 and 2019. Along with the various stress indicators, field spectral measurements were performed in the range of 350–2500 nm. A regression analysis to examine the relation of leaf reflectance to biochemical contents was carried out, to reveal the relevant wavelengths in which polluted and control plants differ. Vegetation indices applied in previous studies were found to be less sensitive for indirect detection of long-term oil contamination. A novel spectral index, based on indicative spectral bands, named the “normalized blue-green stress index” (NBGSI), was established. The NBGSI distinguished significantly between shrubs located in the polluted and in the control areas. The NBGSI showed a strong linear correlation with pheophytin a. Machine learning classification algorithms obtained high overall prediction accuracy in distinguishing between shrubs located in the oil-polluted and the control sites, indicating internal component differences. The findings of this study demonstrate the efficacy of indirect and non-destructive spectral tools for detecting and monitoring oil pollution stress in shrubs.

Removing Crude Oil from Water by Activated Carbon Prepared From Dried Papyrus Plant

Crude oil pollution is a serious problem that causes severe damage to the environment. The adsorption process by using one of the adsorbents is considered one of the most important and successful methods for getting rid and removing crude oil from the water. In this study, activated carbon was used as a sorbent to clean the water from crude oil. This use of activated carbon is new. Adsorption parameters tested included the contact time on adsorption, sorbent dosage, the impact of pH, and temperature. The removal of crude oil from water by activated carbon was investigated by batch adsorption after varying contact time (5–30 min), adsorbent dosage (5–50 g), pH (2–11), and temperature (10–50 0C). hydrophobicity of carbon has increased very significantly due to the modification that was made on carbon, and this, in turn, led to the creation of a sorbent with a very high ability to remove crude oil from the water and thus increase the adsorption capacity. As the results of the study show that the highest value of adsorption capacity was 96% at contact time 20 min, sorbent dosage (25 g), pH (7), and temperature (30 0C). The prepared adsorbent showed the potential to use as a low-cost adsorbent in oil-spill clean-up.

Composting: A Low-cost Biotechnological Approach to Ameliorating Macrophyte Nuisance in Fresh Waters

Water Hyacinth (Eichhornia crassipes), an aquatic macrophyte, is a resource that has attracted a lot of interest in recent times. The physicochemical constituents of Eichhornia crassipes have been reported in some literature to constitute high carbon, nitrogen, phosphorus, potassium including other important micro and macronutrient like potassium and zinc. These findings by scientists informed its utilization in the assemblage of animal feed, bio-energy generation, pharmaceutical industries, and biofilters. The bioconversions of this problematic plant to various products (compost, biochar, and digestate) are green inexpensive options to be considered for use in the restoration of hydrocarbon polluted sites is reviewed in the paper. In addition to crude oil pollution clean-ups, compost improves soil fertility and also increases its organic matter content. This article also shall review composting, Water Hyacinth compost applications in remediation, remediation monitoring parameters, limitations of remediation by composting technology, and the way forward.

Access-dispersion-recovery strategy for enhanced mitigation of heavy crude oil pollution using magnetic nanoparticles decorated bacteria

Heavy crude oil (HCO) pollution has gained global attention, but traditional bioremediating practices demonstrate limited effectiveness. This study developed magnetic nanoparticles decorated bacteria (MNPB) using an oil-degrading and biosurfactant-producing Rhodococcus erythropolis species and identified a novel access-dispersion-recovery strategy for enhanced HCO pollution mitigation. The strategy entails (1) magnetic navigation of the MNPB towards HCO layer, (2) enhanced oil dispersion and formation of suspended oil-bacteria aggregates, and (3) magnetic recovery of these aggregates. The UV-spectrophotometer analysis showed that this strategy can enable up to 62% removal of HCO. The GC–MS analysis demonstrated that the MNPB enhanced the degradation of low-molecular-weight aromatics comparing with the pure bacteria, and the recovery process further removed oil-bacteria aggregates and entrained high-molecular-weight aromatics. The feasibility of using MNPB to mitigate HCO pollution could shed light on the emerging bioremediation applications.

Effect of Oil Pollution on Permeability of the Grey Desert Soil under Freeze-thaw Cycles in Arid Areas of Western China

ABSTRACT There are abundant oil resources in Xinjiang, and the exploitation of oil resources could easily pollute the soil. In this paper, the impact of oil pollution on permeability of the gray desert soil affected by freeze-thaw cycles under a dry and cold climate of Karamay region in Xinjiang was studied. First, varying-head infiltration tests were conducted on soil samples with different water contents and pollution intensity without exposing to freeze-thaw cycles. The variability of permeability were analyzed employing the scanning results of the polluted soil samples by an electron microscope. Then several freezing and thawing cycle tests were implemented on the samples. The test results shown that the soil permeability was optiomal and the permeability coefficient was highest when the crude oil pollution intensity was 0.61% and the water content was 15.53%. With the water content in soil samples being the same, the soil permeability coefficient increased in the beginning and then decreased as the pollution intensity increased. When the pollution intensity ranging from 0.5% to 1.75%, the freezing and thawing condition could be the leading factor affecting the soil permeability. However, when the oil content was within the range of 1.81% – 2.41%, the freezing and thawing condition could not be the leading factor affecting the soil permeability. The results provided in this study could serve as a relevant basis for the remediation of soil pollution in oil production plants in arid areas of Western China.

Recent development on bio‐based thermosetting resins

AbstractDue to the rapid depletion of crude oil and serious environmental pollution, the synthesis of polymers from renewable resource is becoming more and more important. Up to now, a great variety of biomass and bio‐based platform compounds have been taken to prepare the polymers. However, as two representative thermosetting resins, epoxy and benzoxazine resin derived from renewable feedstocks only obtain limited attention compared with the popular bio‐based plastics, including PLA, PBAT and PHBV etc. The reason might be that the properties of previously reported thermosetting resins directly obtained from biomass are usually unsatisfied, and their application fields are limited. In this paper, the latest development on the synthesis of high‐performance bio‐based epoxy and polybenzoxazine resins are reviewed. In addition, to further broaden their applications, the functionalization strategies are also summarized. The objective of this work is to help us fully aware the present situation of bio‐based thermosetting resins and then promote their faster development, especially practical application.

Effects of Environmental Crude Oil Pollution on Newborn Birth Outcomes: A Retrospective Cohort Study.

The World Health Organization encourages countries to improve birth outcomes to reduce rates of neonatal mortality and morbidity. This study was designed to examine the effect of environmental crude oil pollution on newborn birth outcomes in Rivers State, Nigeria. A retrospective cohort design was used to examine the effects of exposure to oil pollution on birth outcomes using facility-based records. K-Dere (an oil-polluted community) served as the exposure group, whereas birth records from Iriebe served as the comparison group. A sample size of 338 systematically selected birth records was examined (169 records for each arm of the study). A data extraction sheet was used for data collection. Data were analyzed using descriptive and inferential statistics at p < .05. The risk of preterm birth was significantly higher in the exposed group (16% vs. 7.7%, relative risk = 2.08, 95% CI [1.11, 3.89], p = .018). At 6 weeks after birth, newborns in the exposed group weighed significantly less (4.64 ± 0.82 vs. 4.85 ± 0.92 kg, p = .032) and reported significantly higher incidence of morbidity compared with the newborns in the comparison group (relative risk = 3.03, 95% CI [2.20, 4.19], p < .001). The oil-polluted area examined in this study was found to have a higher risk of preterm birth, a slower rate of newborn growth, and a higher rate of newborn morbidity than the non-oil-polluted area at 6 weeks after birth. Stakeholders should sustain efforts to remediate the environment in polluted regions and prevent oil pollution. Future research should investigate the mechanisms of the observed toxicological effects and the targeted protection of vulnerable groups in oil-polluted communities.

Zwitterionic hydrogel coated superhydrophilic hierarchical antifouling floater enables unimpeded interfacial steam generation and multi-contamination resistance in complex conditions

• A zwitterionic hydrogel coated evaporator is developed for solar steam generation. • The superhydrophilic surfaces and channels guarantee unimpeded water supply. • The evaporator possesses multi-contamination resistance to salt, oil, and biofouling. Continuous water pumping and steam generation are key factors in long-term solar-driven evaporation for fresh water production. However, current solar desalination devices easily get contaminated by salt accumulation, oil spill or marine fouling in real-world applications, causing blockage, corrosion or even invalidation. Developing antifouling coatings that can protect the devices from multi-contamination is a superior option to guarantee the longevity of the devices and stable fresh water generation. Herein, a superhydrophilic hierarchical antifouling floater (SHAF) consisted of zwitterionic hydrogel coated polyurethane (PU), polystyrene (PS) foam and cotton swabs, is developed. The porous PU fabric is competent to fragment water into ultra-fine droplets, increasing the vapor pressure and promoting the evaporation process. The zwitterionic coating can bind water molecules to form a hydration layer, thus leading to stable water transport and fascinating fouling resistance. Integrated with these merits, this SHAF accelerates water evaporation rate up to ~2.2 kg m −2 h −1 with a photothermal conversion efficiency of 93.5%. It also exhibits prominent microbial resistance with 96.2% against E. coli and ~100% against diatom. Additionally, due to the hydration shield induced by the zwitterionic coating, the SHAF surface is endowed with self-cleaning property even against crude oil pollution. Therefore, the SHAF with highly efficient water evaporation and multi-contamination resistance is a potential candidate for solar-driven fresh water production from seawater or even wastewater.

Changes of Heart Rate and Lipid Composition in Mytilus Edulis and Modiolus Modiolus Caused by Crude Oil Pollution and Low Salinity Effects.

Blue mussels, Mytilus edulis, inhabiting tidal zones, are naturally exposed to fluctuating environmental conditions (e.g., fluctuations in temperature and salinities), while horse mussels, Modiolus modiolus, live under relatively invariable shelf water conditions. The present investigation tested the hypothesis: blue mussels, in comparison to horse mussels, have an increased ability to tolerate the stress of pollution combined with low salinity. To assess the response of blue mussels and horse mussels to oil pollution at seawater salinities of 25 psu (normal) and 15 psu (low), we used a combination of heart rate and lipid composition as physiological and biochemical indicators, respectively. A sharp decrease in heart rate as well as important fluctuations in cardiac activity was observed under all oil concentrations. Modifications in the concentrations of the main membrane lipid classes (phosphatidylcholine, phosphatidylethanolamine, and cholesterol) and storage lipids (primarily triacylglycerols) in response to different crude oil concentrations were time- and dose-dependent. Both chosen indicators showed a high sensitivity to crude oil contamination. Furthermore, both bivalve species showed similar responses to oil pollution, suggesting a universal mechanism for biochemical adaptation to crude oil pollution.

Attenuation of petroleum hydrocarbon fractions using rhizobacterial isolates possessing alkB, C23O, and nahR genes for degradation of n-alkane and aromatics

This work assessed the catabolic versatility of functional genes in hydrocarbon-utilizing bacteria obtained from the rhizosphere of plants harvested in aged polluted soil sites in Ogoni and their attenuation efficacy in a bioremediation study. Rhizosphere soil was enumerated for its hydrocarbon-utilizing bacteria. The bacteria were in-vitro screened and selected through the quantification of their total protein and specific intermediate pathway enzyme (catechol 2,3-dioxygenase) activity in the metabolism of hydrocarbon. Thereafter, agarose gel electrophoresis technique was deployed to profile the genome of the selected strains for catechol 2,3-dioxygenase (C23O), 1,2-alkane monooxygenase (alkB), and naphthalene dioxygenase (nahR). Four rhizobacterial isolates namely Pseudomonas fluorescens (A3), Achromobacter agilis (A4), Bacillus thuringiensis (D2), and Staphylococcus lentus (L1) were selected based on the presence of C23O, alkB, and nahR genes. The gel electrophoresis results showed an approximate molecular weight of 200 bp for alkB, 300 bp for C23O, and 400 bp for nahR. The gas chromatogram for residual total petroleum hydrocarbon (TPH) revealed mineralization of fractions C8–C17, phytane, C18–C30. TPH for in-vitro bioremediation of crude oil-polluted soil was observed to have an optimal reduction/loss of 97% within the 56th day of the investigation. This study has further revealed that the microbiome of plants pre-exposed to crude oil pollution could serve as a reservoir for mining group of bacterial with broad catabolic potentials for eco-recovery and waste treatment purposes.

Microbiology and Heavy Metal Content of Wetlands Impacted by Crude Oil Pollution in Rivers State, Southern Nigeria

Wetland soils constitute vast, under-exploited and sometimes undiscovered ecologies in many countries of the World, including Nigeria. A total of 54 wetland soil samples including surface and subsurface soil at depths of 0-15 cm and 15-30 cm were collected using a sterile hand auger for a period of three months between August and October and subjected to standard and analytical microbiological procedures. The wetland soil samples were further subjected to atomic absorption spectroscopy (AAS) to check for presence and concentration of heavy metals. Results obtained showed that apart from heterotrophic bacterial and fungal counts, hydrocarbon utilizing bacteria (HUB) counts were higher in the surface soil ranging from 12.06±3.43bX107 cfu/g at Iwofe to 6.19±2.67aX107 cfu/g at Chokocho while subsurface soil had HUB ranging from 8.91±6.67aX103 cfu/g at Eagle Island to 4.93±3.95aX103cfu/g at Chokocho. Heavy metals such as Fe, Pb, Cd and Ni were recorded in concentrations above FEPA permissible limit in the surface and subsurface soil across the three wetlands. The heavy metal concentration in each wetland however, decreased with an increase in soil depth. According to literatures, elevated levels of heavy metals in soils decrease microbial population, diversity and activities. However, the microbial population in this study increased with increasing heavy metal concentration which indicates that the microbes can tolerate or utilize heavy metals in their systems; as such can be used for bioremediation of heavy metal polluted soils.

Removal of crude oil by Thiobacillus sp. and Clostridium sp. at various temperatures and concentration of pollutant in liquid media

The activities of the petroleum mining industry in Indonesia have caused many problems by producing hazardous waste pollution that would produce dangers for plants, animals or human lives. One technique to recover environmental situation is through land farming technique. The purpose of this study is to overcome crude oil pollution in the environment by using biotechnology method through the process of enzymatic bioremediation. The parameters discussed to determine the optimal environmental conditions that provide the highest efficiency for Total Petroleum Hydrocarbon (TPH) degradation processes such as temperature with a variation of 25 – 45°C then the concentration of pollutants with a variation of 5% – 20%, and the contact time carried out in solid media with variations amounting to 3 – 21 days. After conducting research, research that produces the bacterium Thiobacillus sp. and Clostridium sp. under optimal conditions at 35°C with a pollutant concentration of 10% and a contact time of 14 days. Thus, it can be concluded that the bacterium Thiobacillus sp. and Clostridium sp. can set aside hydrocarbon compounds with a removal efficiency of 65%. So, this research needs to be done to study other physical parameters.

Gill and liver transcriptomic responses of Achirus lineatus (Neopterygii: Achiridae) exposed to water-accommodated fraction (WAF) of light crude oil reveal an onset of hypoxia-like condition.

Crude oil is one of the most widespread pollutants released into the marine environment, and native species have provided useful information about the effect of crude oil pollution in marine ecosystems. We consider that the lined sole Achirus lineatus can be a useful monitor of the effect of crude oil in the Gulf of Mexico (GoM) because this flounder species has a wide distribution along the GoM, and its response to oil components is relevant. The objective of this study was to compare the transcriptomic changes in liver and gill of adults lined sole fish (Achirus lineatus) exposed to a sublethal acute concentration of water-accommodated fraction (WAF) of light crude oil for 48 h. RNA-Seq was performed to assess the transcriptional changes in both organs. A total of 1073 differentially expressed genes (DEGs) were detected in gills; 662 (61.69%) were upregulated, and 411 (38.30%) were downregulated whereas in liver, 515 DEGs; 306 (59.42%) were upregulated, and 209 (40.58%) were downregulated. Xenobiotic metabolism and redox metabolism, along with DNA repair mechanisms, were activated. The induction of hypoxia-regulated genes and the generalized regulation of multiple signaling pathways support the hypothesis that WAF exposition causes a hypoxia-like condition.

English

Crude oil spill destroys biodiversity and adversely impacts the physicochemical characteristics of the terrestrial and aquatic environments. The population characteristics of soil nematodes can serve as indicators of alterations in the terrestrial environment. To determine the effects of crude oil spillage on the soil nematode fauna status; a study was carried out at an impacted area in Gokana Local Government Area of Rivers State, Nigeria. 60 soil samples were randomly collected vertically (30 from the unpolluted sites and 30 from the polluted sites) at designated depths of 0-5 cm, 6-10 cm and 11-15 cm with the aid of a calibrated soil corer. Soil samples were taken to the laboratory for nematode extraction using the Baermann’s extraction technique and the sieving method. Physiochemical parameters of the soil samples were determined using standard laboratory techniques. A total of 340 nematodes (from 11 genera) were recovered in the soil samples comprising; 169 (49.7%) nematodes from polluted sites and 171 (50.3%) nematodes from the unpolluted sites. There was slight variability in nematode species diversity, richness and abundance in the polluted and unpolluted sites (p>0.05). Crude oil pollution influenced soil nematodes community composition while anthropological interferences such as farming influenced the successional trend of which was reflected in the maturity index values obtained from the study. Key words: Crude oil, soil nematodes, biodiversity, polluted sites and maturity index.