Terrestrial Oil Research Articles

Terrestrial Oil Spills Recognition Based on Small Samples From UAV Multispectral Images

Terrestrial Oil Spills Recognition Based on Small Samples From UAV Multispectral Images

The foraging behavior of gerbils reveals the ecological significance of crude oil pollution

Despite extensive ecotoxicological evidence on the adverse effects of oil pollution on rodents, little is known about how rodents make decisions in oil-polluted environments (i.e., outside of lab settings). We investigated the foraging behavior of Allenby gerbils, Gerbillus andersoni allenbyi (GA), that were presented with feeding trays in a semi-natural environment. The trays contained seeds mixed into one of three types of soils – clean soil, and two different soil samples collected from two well-documented terrestrial oil spill sites in Israel. The oil spill disasters occurred in 1975 and 2014 and the spill sites are located within a few hundred meters of each other, in the 'Avrona Nature Reserve in the Arava hyper-arid region in Israel.Gerbils of both sexes avoided foraging in 2014-polluted soil, but surprisingly, they foraged more in 1975-polluted soil. Our results indicate that for the GA, the 1975-polluted soil is an advantageous substrate to forage on, probably because its texture facilitates more efficient foraging, leading to greater energetic gain, and creating a trade-off between energetic gain and perceived foraging cost due to its pollution. We also proceeded to investigate some physiological consequences of chronic exposure to the 2014-polluted soil in the laboratory. Chronic oil exposure did not lead to mortality or weight loss, but female gerbils exhibited heightened cortisol. We conclude that terrestrial oil pollution may have significant sublethal impacts on animal behavior, even when there is no obvious short-term physiological cost to the exposure.

Cultivation of novel Atribacterota from oil well provides new insight into their diversity, ecology, and evolution in anoxic, carbon-rich environments

BackgroundThe Atribacterota are widely distributed in the subsurface biosphere. Recently, the first Atribacterota isolate was described and the number of Atribacterota genome sequences retrieved from environmental samples has increased significantly; however, their diversity, physiology, ecology, and evolution remain poorly understood.ResultsWe report the isolation of the second member of Atribacterota, Thermatribacter velox gen. nov., sp. nov., within a new family Thermatribacteraceae fam. nov., and the short-term laboratory cultivation of a member of the JS1 lineage, Phoenicimicrobium oleiphilum HX-OS.bin.34TS, both from a terrestrial oil reservoir. Physiological and metatranscriptomics analyses showed that Thermatribacter velox B11T and Phoenicimicrobium oleiphilum HX-OS.bin.34TS ferment sugars and n-alkanes, respectively, producing H2, CO2, and acetate as common products. Comparative genomics showed that all members of the Atribacterota lack a complete Wood-Ljungdahl Pathway (WLP), but that the Reductive Glycine Pathway (RGP) is widespread, indicating that the RGP, rather than WLP, is a central hub in Atribacterota metabolism. Ancestral character state reconstructions and phylogenetic analyses showed that key genes encoding the RGP (fdhA, fhs, folD, glyA, gcvT, gcvPAB, pdhD) and other central functions were gained independently in the two classes, Atribacteria (OP9) and Phoenicimicrobiia (JS1), after which they were inherited vertically; these genes included fumarate-adding enzymes (faeA; Phoenicimicrobiia only), the CODH/ACS complex (acsABCDE), and diverse hydrogenases (NiFe group 3b, 4b and FeFe group A3, C). Finally, we present genome-resolved community metabolic models showing the central roles of Atribacteria (OP9) and Phoenicimicrobiia (JS1) in acetate- and hydrocarbon-rich environments.ConclusionOur findings expand the knowledge of the diversity, physiology, ecology, and evolution of the phylum Atribacterota. This study is a starting point for promoting more incisive studies of their syntrophic biology and may guide the rational design of strategies to cultivate them in the laboratory.5rnPv2dUCRDw24_qsw9GBLVideo

Medium-short chain fatty acids cannot spare the essential fatty acids of low marine diets in golden pompano (Trachinotus ovatus)

Based on the essential fatty acids (EFA) precision nutrition, a blend oil (BO) of fish oil and terrestrial oils was developed, and applied successfully to the low marine diets of golden pompano (Trachinotus ovatus). To evaluate whether medium- and short-chain fatty acids (MCFA and SCFA), efficient energy supplements for animals, can spare the dietary EFA, four iso-proteic (48%) and iso-lipidic (11%) low fishmeal (FM) diets (D1-D4, contained 6% FM) were formulated and fed T. ovatus juveniles (initial weight ∼8.50 g) for 9 weeks in sea cages. Control diets (D1) contained 8% BO, while the BO of diets D2-D4 were replaced 50% with coconut oil, coconut oil + sodium butyrate, and coconut oil + n-3 LC-PUFA enriched oil, respectively. The results showed that compared to the D1 group, the growth performance of D2 and D3 were significantly lower, while a comparable growth was detected in the D4 group. The muscle and hepatic n-3 PUFA levels in the D2 and D3 groups were significantly low, and these fatty acid contents were modified in the D4 group. Meanwhile, the muscle textural firmness of the D2-D4 groups was decreased. Regarding the health index of fish, compared to the D1 group, high serum triglyceride (TG) contents and low HDL/LDL ratio were detected in the D2-D4 groups, and high ACP, AST, and ALT activities were observed in these groups. Meanwhile, high HSI and low hepatic enzymatic activities of CAT and ALT were measured in the D2-D3 groups. Additionally, the mRNA levels of hepatic fatty acid synthesis-related genes (fas, acc, and pparγ) were significantly increased in D2-D4 groups, and the expression levels of lipid catabolism genes (cpt-1 and lpl) showed an upward trend. Moreover, the D2 group exhibited the lowest intestinal wall thickness, the mRNA levels of intestine anti-inflammatory cytokines (il-10) were up-regulated in the D2-D4 groups, and the highest mRNA levels of pro-inflammatory cytokines (il-8) were detected in the D2 group. In conclusion, the EFA deficiency leads to a decline in the growth and muscle quality of T. ovatus fed low marine diets, which cannot be mitigated by the addition of medium-short chain fatty acids. The results indicated that MCFA and SCFA cannot spare the EFA of low marine diets in T. ovatus.

Oil spill soil remediation using thermal desorption: Project synthesis and outcomes

AbstractFarmland within the Williston Basin of North Dakota was the site of the largest terrestrial oil spill to date in the United States in 2013. Over 3200 m3 of oil was released into the topsoil and subsoil, creating a risk to soil, water, and air resources. The purpose of this document is to provide a summary of results from a 7‐year project investigating the impacts of how thermal desorption (TD), the method used to remediate topsoil and subsoil, impacted contaminant reduction, soil function, and plant productivity simultaneously with site remediation. Soil disturbance and TD decreased soil organic matter and microbial communities, resulting in decreased soil function and plant production. However, TD did not reduce soil microbial recovery 4 years after treatment. Blending TD‐treated soil with uncontaminated topsoil appeared to minimize these negative effects and promote recovery of soil function. These findings provided critical information to stakeholders in the understanding of soil remediation and reclamation in this region.

Characterization of the Mycoremediation of n-Alkanes and Branched-Chain Alkanes by Filamentous Fungi from Oil-Polluted Soil Samples in Kazakhstan.

For decades, researchers have focused on containing terrestrial oil pollution. The heterogeneity of soils, with immense microbial diversity, inspires them to transform pollutants and find cost-effective bioremediation methods. In this study, the mycoremediation potentials of five filamentous fungi isolated from polluted soils in Kazakhstan were investigated for their degradability of n-alkanes and branched-chain alkanes as sole carbon and energy sources. Dry weight estimation and gas chromatography-mass spectrometry (GC-MS) monitored the growth and the changes in the metabolic profile during degradation, respectively. Penicillium javanicum SBUG-M1741 and SBUG-M1742 oxidized medium-chain alkanes almost completely through mono- and di-terminal degradation. Pristane degradation by P. javanicum SBUG-M1741 was >95%, while its degradation with Purpureocillium lilacinum SBUG-M1751 was >90%. P. lilacinum SBUG-M1751 also exhibited the visible degradation potential of tetradecane and phytane, whereby in the transformation of phytane, both the mono- and di-terminal degradation pathways as well as α- and ß-oxidation steps could be described. Scedosporium boydii SBUG-M1749 used both mono- and di-terminal degradation pathways for n-alkanes, but with poor growth. Degradation of pristane by Fusarium oxysporum SBUG-M1747 followed the di-terminal oxidation mechanism, resulting in one dicarboxylic acid. These findings highlight the role of filamentous fungi in containing oil pollution and suggest possible degradation pathways.

Evaluation of Re–Os geochronology and Os isotope fingerprinting of Late Cretaceous terrestrial oils in Taranaki Basin, New Zealand

The rhenium-osmium (Re–Os) isotope system has been applied to several marine and lacustrine petroleum systems worldwide, showing good potential for dating crude oils and correlating them to their source rocks. Here we explore the applicability of the Re–Os geochronometer and Os isotope fingerprinting to terrestrial oils by comparing the Re and Os systematics of Late Cretaceous terrestrial oils from Taranaki Basin, New Zealand, and their correlated coaly source rocks. Comparison is also made with selected Late Cretaceous–Paleocene marine oils and source rocks with varying levels of terrestrial organic matter input.The asphaltene fractions of nine genetically related terrestrial oils from the Maui, Maari-Manaia and Tui Area fields in offshore Taranaki Basin contain low concentrations of Re (0.18–0.45 ppb) and 192Os (1.3–12.7 ppt) comparable to their correlated Late Cretaceous coaly source rocks (Rakopi and North Cape formations; Re 0.19–0.37 ppb, 192Os 5.3–9.6 ppt). The Re and 192Os concentrations in these terrestrial oils are generally one to two orders of magnitude lower than those in marine-sourced oils from the Kora Field in offshore Taranaki Basin and surface seeps in East Coast Basin.The 187Re/188Os and 187Os/188Os ratios of the terrestrial oils failed to yield a precise Re–Os isochron age. We attribute this to: (1) insufficient homogenisation of oils with widely variable initial 187Os/188Os (Osi) values inherited from thick, coaly source rock intervals (up to about 2700 m) within the Maui sub-basin and northern Kahurangi Trough kitchens; (2) insufficient spread of 187Re/188Os values (only 275 units); (3) insufficient time since oil expulsion (modelled to be from approximately 10 Ma to the present day) for the evolution of an isochron; and (4) possible effects of water washing of the oil columns. Although all of the studied oils are water-washed to varying degrees, there is no definitive evidence that water washing has disturbed the Re–Os systematics.The Osi values for the studied terrestrial oils inherited at the modelled time of oil expulsion (approximately 10 Ma) display a wide range (0.47–1.14) and do not provide a unique fingerprint of their Late Cretaceous coaly source rock formations. Osmium isotope compositions therefore appear to have limited potential for broad oil-source rock correlation within the predominantly coal-sourced petroleum systems of Taranaki Basin. The Osi values may, however, provide useful distinction of the terrestrial oils emanating from the Kahurangi Trough (Tui Area oils) from those of the Maui sub-basin (Maui and Maari-Manaia oils) based on the significantly more radiogenic values of the Tui Area oils (0.84–1.14 compared with 0.47–0.65 from Maui and Maari-Manaia oils). Overall, this study has provided useful insights into the potential application of the Re–Os isotope system to terrestrial, coal-sourced petroleum systems.

Hydrocarbon potential of shales and lignites of Oligocene-Miocene Ogwashi-Asaba formation exposed in Issele-Uku of Anambra Basin, Southern Nigeria as both conventional and unconventional resources

Hydrocarbon potentials of lignites and shales of Oligocene-Miocene Ogwashi-Asaba Formation outcropping along springs at Issele-Uku and Azagba-Ogwashi areas of Anambra Basin, Southern Nigeria were investigated through total organic carbon (TOC), Rock-Eval pyrolysis and organic petrology analyses. Lignite has an average TOC of 47.20 wt.% and shale of 9.15 wt.%, suggesting good to excellent source rocks. Sporinite, resinite, and humodetrinite are the dominant sub-maceral. Ratios of average huminite, liptinite, and inertinite maceral group (H:L:I) in lignite from Nnem-Agadi, Iyiodo, Mgbala, and Nkpunkpa are 55:35:10, 66:24:10, 62:25:13, and 58:30:12, respectively, while for shales in Nnem-Agadi is 57:28:15 and Iyiodo is 55:20:15. Average hydrogen index (HI) of lignite is 436 mgHC/gTOC, and shale is 218 mgHC/gTOC. HI of 783 mgHC/gTOC in one lignite from Nnem-Agadi indicates Type I oil-prone kerogen typical of algae-sourced organic matter, whereas Type II oil and gas kerogen is present in both lignites and shales. Type III gas-prone kerogen is found only in shale. Genetic potential of 106.95 kgHC/t) in lignites and 20.87 kgHC/t in shales indicate excellent and moderate oil and gas potentials. All the source rocks are immature at the current outcrop positions but could have possibly attained maturity in the deeper subsurface area of the basin and contributed to the petroleum systems in the Anambra Basins. Ogwashi-Asaba formation has similar source rocks and organic matter types with the ones generating mixed marine and terrestrial oil within Agbada Formation, in the Niger Delta Basin. These source rocks are significant Oligocene-Miocene conventional and unconventional hydrocarbon resources depending on their current depth in the rift basins in West and Central Africa.

Synergies and Trade-Offs in Reducing Impacts of Unconventional Oil and Gas Development on Wildlife and Human Health

AbstractWith growing evidence of widespread health and environmental impacts from oil and gas activity, localities and states are beginning to develop protective measures. Interdisciplinary approaches that integrate across human, wildlife, domesticated animal, and land health are likely to provide more just and comprehensive solutions than would be possible with siloed approaches. However, this is not common practice, and there is little guidance on how to apply such a strategy. In the present article, we summarize the state of knowledge on the impacts of terrestrial unconventional oil and gas development from the fields of ecology and public health. We then discuss synergies and trade-offs regarding impacts and mitigation strategies emerging from these two literatures. Finally, we provide recommendations for research and practice to fill knowledge gaps and better inform integrated decision-making to achieve multiple benefits and minimize impacts on human, wildlife, domesticated animals, and land health from energy development.

Integrated Analysis of Metabolomics and Transcriptomics for Assessing Effects of Fish Meal and Fish Oil Replacement on the Metabolism of Rainbow Trout (Oncorhynchus mykiss)

Reducing dependency on dietary fish meal (FM) and fish oil (FO) is extremely important for the sustainable development of the aquaculture industry. However, the metabolic consequences and mechanisms underlying the replacement of dietary FM and FO by terrestrial proteins (TPs) and lipids remain unclear. To reveal the effects of replacing dietary FM and/or FO on the metabolic changes, the integrated analysis of metabolomics and transcriptomics were employed to evaluate the changes in metabolites and genes of rainbow trout (Oncorhynchus mykiss) feeding different experimental diets. Four diets were formulated for the 84-day duration of the experiment: control group (FMFO), FM and vegetable oil (FMVO), terrestrial protein and FO (TPFO), and terrestrial protein and vegetable oil (TPVO). Integrated metabolomic and transcriptomic analyses revealed the significant difference in the metabolic pathways of O. mykiss among the three replacement schemes, i.e., single replacement of dietary FM by TP, single replacement of dietary FO by VO, and combined replacement of FM by TP and FO by VO. The combined replacement of FM and FO by TP and VO, respectively, disturbed immune function, energy metabolism, cellular protein biosynthesis capacity, and lipid metabolism of O. mykiss. The reduction of antioxidant capacity was only observed in individuals feeding diets with replacement of FM by TP. Furthermore, as soon as the dietary FM and/or FO were reduced, cellular protein biosynthesis ability was suppressed and accompanied by higher energy consumption in response to fluctuations of dietary quality, resulting in reduced growth performance. Interestingly, adenylosuccinate and adenosine monophosphate involved in purine metabolism were induced by both individual and combined replacement of FM and FO by TPs and lipids, respectively. It suggested that these two metabolites might be potential biomarkers for O. mykiss fed diets with reduction of FM and/or FO. This study constitutes a new understanding of the molecular and metabolic mechanisms of O. mykiss in response to the replacement of dietary FM and/or FO by TP and/or VO, respectively, and built a theoretical basis for further improvement of aquafeed formulation and sustainable development of aquaculture.

Mercury Isotopes in Shale Gas From Wufeng-Longmaxi Shale Formation of Sichuan Basin, Southern China: A Preliminary Investigation

A series of investigations have been conducted concerning the study of traditional stable isotopes and rare gas stable isotopes in natural gas. However, little is known regarding non-traditional stable isotopes of mercury in natural gas, especially in the development and utilization of shale gas in recent years. In fact, the presence of mercury in natural gas (including shale gas) provides a basis for research on mercury isotopes. Mercury was extracted from shale gas at the Wufeng-Longmaxi Formation in the YS108 block of the Zhaotong National shale gas demonstration area in the Sichuan Basin by using an acid potassium permanganate solution, followed by the analysis of mercury content and stable isotope composition. The mercury content in the marine shale gas at the Wufeng-Longmaxi Formation ranged from 171 to 2,906 ng/m3, with an average of 1,551.08 ± 787.08 ng/m3 (n = 37, 1 SD). The Δ199Hg values of mercury stable isotopes range from 02‰ to 0.39‰, with an average of 22‰ ± 0.08‰ (n = 37, 1 SD); the δ202Hg values range from −1.68‰ to −0.04‰, with an average of −0.87‰ ± 0.31‰ (n = 37, 1 SD), which are significantly different from the Δ199Hg and δ202Hg information of coalbed gas, but similar to the Δ199Hg and δ202Hg information of terrestrial oil-type gas and the Δ199Hg in the main hydrocarbon-forming organic matter of lower organisms such as algae (t-test, p > 0.05). This indicates that terrestrial target strata with abundant algae or strata with positive Δ199Hg are the target strata for the exploration of terrestrial oil and gas.

Formation Pressure Inversion Method Based on Multisource Information

SummaryThe exploration and development of offshore oil and gas have greatly alleviated the tension of global oil and gas resources. However, the abnormal pressure of offshore reservoirs is more common compared with terrestrial oil and gas reservoirs, and the marine geological structure is complex, with the development of faults, fractures, and high and steep structures, which leads to the strong anisotropy of formation pore pressure distribution and uncertainty of pressure system change. In this paper, considering the corresponding characteristics of the randomness of the formation pressure prediction results in the Eaton equation for their respective variables, a formation pressure inversion method based on multisource information, such as predrilling data, bottomhole while drilling data, seabed measured data, and surface measured data, is established. On this basis, combined with the data of a well in the South China Sea, the variation law of the uncertainty of formation pressure prediction results under the conditions of predrilling data, measurement while drilling (MWD) data, and their mutual coupling is analyzed. The simulation results show that the uncertainty distribution of formation pressure prediction based solely on predrilling data shows linear accumulation trend with well depth, and the formation pressure inversion method based on multisource information can significantly curb the increasing trend of uncertainty when MWD data are introduced. Therefore, through the analysis of typical change patterns of monitoring parameters under normal/abnormal conditions during drilling, combined with the method of multisource information, the abnormal pressure information can be accurately predicted and inversed, which provides important support for wellbore pressure regulation under complex formation conditions.

Evaluation of Re-Os Geochronology and Os Isotope Fingerprinting of Late Cretaceous Terrestrial Oils in Taranaki Basin, New Zealand

Evaluation of Re-Os Geochronology and Os Isotope Fingerprinting of Late Cretaceous Terrestrial Oils in Taranaki Basin, New Zealand

Terrestrial oil spill mapping using satellite earth observation and machine learning: A case study in South Sudan

Terrestrial oil spills are a major threat to environmental and human well-being. Rapid, accurate, and remote spatial assessment of oil contamination is critical to implementing countermeasures that prevent potentially lasting ecological damage and irreversible harm to local communities. Satellite remote sensing has been used to support such assessments in inaccessible regions, although mapping small terrestrial oil spills is challenging – partly due to the pixel size of remote sensing systems, but also due to the distinguishability of small oil spill areas from other land cover types. We assessed the usability of freely available Sentinel satellite images to map terrestrial oil spills with machine learning algorithms. Using two test sites in South Sudan, we demonstrated that information from the Sentinel-1 and -2 instruments can be used to map oil spills with more than 90 % classification accuracy. Classification accuracy was significantly increased (>95 %) with the addition of multi-temporal information and spatial predictor variables that quantify proximity to oil production infrastructure such as pipelines and oil pads. The mapping of terrestrial oil spills with freely available Sentinel satellite images may thus represent an accurate and efficient means for the regular monitoring of oil-impacted areas.

Optimizing the fatty acid profile of novel terrestrial oil blends in low fishmeal diets of rainbow trout (Oncorhynchus mykiss) yields comparable fish growth, total fillet n-3 LC-PUFA content, and health performance relative to fish oil

Identifying and effectively utilizing suitable, novel, terrestrial oil sources either alone or as blends to replace fish oil (FO) is a prerequisite for improving the sustainability of global aquaculture. Therefore, the present study evaluates several novel terrestrial oil blends (TOBs), optimized for their fatty acid profile, as alternatives to FO in low fishmeal diets fed to rainbow trout (Oncorhynchus mykiss) and describes the subsequent effects on fish growth, fatty acid composition and health. Insect oil (IO), genetically modified canola oil (CO), palm oil (PO) and linseed oil (LO) were used for the formulation of three TOBs viz., TOB-1 (30%IO+36%CO + 34%LO), TOB-2 (40%PO + 20%CO + 40%LO) and TOB-3 (50%TOB-1 + 50%TOB-2). Formulas TOB-1 and TOB-2 considered the total fatty acid profile based upon the general FO fatty acid profile, published fatty acid research for rainbow trout, and the fatty acid requirements of rainbow trout. A low fishmeal based basal diet containing 44% crude protein was formulated, and FO, TOB-1, TOB-2 and TOB-3 were incorporated in the basal diet to prepare the experimental diet groups, Control, TOB-1, TOB-2 and TOB-3, respectively. All experimental diets were fed to triplicate groups of rainbow trout juveniles (initial weight 7.9 ± 0.02 g) for 9 weeks. Growth performance (final weight, percent weight gain and specific growth rate) in TOBs fed groups were equal to the FO-based control group. Fish fed the TOB-3 diet consumed more feed followed by the control and TOB-1 diet groups. Significantly lower feed intake was observed in the TOB-2 diet group. Feed conversion ratio and protein efficiency ratio were not significantly influenced by dietary oil sources. Fish fed the control diet showed significantly higher hepatic lipid content compared to TOB groups, followed by TOB-2, TOB-3, and TOB-1, which was significantly lower in hepatic lipid content. Muscle lipid content and whole-body major nutrient compositions were not significantly influenced by the dietary oil sources. Fatty acid composition of muscle and liver reflected that of the diets. Maximum values for n3 LC-PUFAs (EPA and DHA), lauric acid (C12:0) and C18:3n-3 were observed in the FO, TOB-1 and TOB-2 groups, respectively. Except for C12:0, muscle saturated fatty acid contents were significantly lower in TOBs-based diet compared to the FO-based control diet fish. As expected, muscle C12:0 content was significantly higher in the TOB-1 group followed by the TOB-3 group. TOB-2 and control groups had significantly lower content of C12:0. The fillet total n-3 LC-PUFA was significantly higher in fish fed the control diet group followed by TOB-3 and TOB-2 groups, TOB-1 showed significantly lower content of total n-3 LC- PUFA. Hepatic delta-5 desaturase (Δ5fad), delta-6 desaturase (Δ 6fad) and fatty acid elongase-2 (Elovl-2) gene expressions were significantly influenced by dietary oil sources, where TOB-based groups showed higher Δ6fad and Elovl-2 expressions. Measured innate immunity and antioxidant markers were not affected by TOBs. Finally, we concluded that TOBs could serve as a substitute for FO in rainbow trout feed without negatively impacting performance. Moreover, fillet total n-3 LC-PUFA of TOB-fed fish satisfies the suggested daily serving for humans.

Catalytic Hydroprocessing of Single-Cell Oils to Hydrocarbon Fuels

Microbial lipids hold great promise as biofuel precursors, and research efforts to convert such lipids to renewable diesel fuels have been increasing in recent years. In contrast to the numerous literature reviews on growing, characterising and extracting lipids from oleaginous microbes, and on converting vegetable oils to hydrocarbon fuels, this review aims to provide insight into aspects that are specific to hydroprocessing microbial lipids. While standard hydrotreating catalysts generally perform well with terrestrial oils, differences in lipid speciation and the presence of co-extracted compounds, such as chlorophyll and sterols, introduce additional complexities into the process for microbial lipids. Lipid cleanup steps can be introduced to produce suitable feedstocks for catalytic upgrading.

The effects of biostimulation and bioaugmentation on crude oil biodegradation in two adjacent terrestrial oil spills of different age, in a hyper-arid region

This study deals with two adjacent terrestrial oil spills, with similar properties, located in a hyper-arid region in Israel, one from 1975 and the other from 2014. It tests the effect of biostimulation on crude oil degradation in both spills and whether biostimulated sediments from the 1975 spill can bioaugment crude oil degradation in the 2014 spill. Soil hydrophobicity, expressed as Water Drop Penetration Time (WDPT), and Gasoline Range Organics (GRO) and Diesel Range Organics (DRO) content in sediments were measured in one-month ex-situ experiments. No significant reduction in hydrophobicity and GRO + DRO content was observed in non-biostimulated controls. A combined treatment of mineral fertilization at t0 and maintaining 50% water saturation, significantly accelerated the decrease in hydrophobicity and GRO + DRO content in sediments of both spills. The addition of biostimulated sediments from the 1975 spill failed to accelerate the reduction of GRO + DRO content and hydrophobicity in the 2014 spill. Surprisingly, the GRO + DRO degradation rate in biostimulated sediments from the 2014 spill was 36% higher than in biostimulated sediments from the 1975 spill. Crude oil composition in both spills changes during its degradation and is characterized by an increase in the GRO fraction. To a certain range, WDPT was found to serve as a reliable indicator for oil content in the soil. We conclude that even in a hyper-arid region, oil bio-degradation capabilities develop in a relatively short time. Moreover, while biostimulation was effective in accelerating biodegradation, bioaugmentation with biostimulated sediments from a nearby older spill was found ineffective.

Effects of Varying Dietary Docosahexaenoic, Eicosapentaenoic, Linoleic, and α-Linolenic Acid Levels on Fatty Acid Composition of Phospholipids and Neutral Lipids in the Liver of Atlantic Salmon, Salmo salar

Fish oil, the most abundant natural source of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), is a limited resource; however, terrestrial oils are used as an alternative in fish nutrition. The liver of Atlantic salmon is able to synthesize these two long-chain n-3 polyunsaturated fatty acids (n-3LC-PUFAs) from α-linolenic acid (ALA), but the dietary levels of EPA + DHA and the ratios of linoleic acid (LNA) to ALA may affect its abilities. Feeding Atlantic salmon four experimental diets containing EPA + DHA at 0.3 and 1.0% of dietary levels accompanied with high and low LNA/ALA ratios showed that low LNA/ALA ratios increased the proportions of EPA + DHA in phospholipids (PLs) and neutral lipids (NLs). The pattern of PL-to-NL ratios of n-3 LC-PUFA proportions matched the saw tooth pattern of LNA/ALA ratios in diets. Overall, when fish oil is removed from salmon diets, the dietary LNA/ALA ratio must be reduced to stimulate biosynthesis of n-3 LC-PUFAs in the liver.

Seasonal effects on growth and product quality in Atlantic salmon fed diets containing terrestrial oils as assessed by a long‐term, on‐farm growth trial

Seasonal effects on growth and product quality in Atlantic salmon fed diets containing terrestrial oils as assessed by a long‐term, on‐farm growth trial

The Impact of Terrestrial Oil Pollution on Parasitoid Wasps Associated With Vachellia (Fabales: Fabaceae) Trees in a Desert Ecosystem, Israel.

Oil is a major pollutant of the environment, and terrestrial oil spills frequently occur in desert areas. Although arthropods account for a large share of animal diversity, the effect of oil pollution on this group is rarely documented. We evaluated the effects of oil pollution on parasitoid wasps associated with Vachellia (formerly Acacia) tortilis (Forssk.) and Vachellia raddiana (Savi) trees in a hyper-arid desert that was affected by two major oil spills (in 1975 and 2014). We sampled the parasitoid populations between 2016 and 2018 in three sampling sites and compared their abundance, diversity, and community composition between oil-polluted and unpolluted trees. Parasitoid abundance in oil-polluted trees was lower in one of the sites affected by the recent oil spill, but not in the site affected by the 1975 oil spill. Oil-polluted trees supported lower parasitoid diversity than unpolluted trees in some sampling site/year combinations; however, such negative effects were inconsistent and pollution explained a small proportion of the variation in parasitoid community composition. Our results indicate that oil pollution may negatively affect parasitoid abundances and diversity, although the magnitude of the effect depends on the tree species, sampling site, and the time since the oil spill.