Oil Spill Risk Research Articles

Long-term performance and durability of lime-stabilized oil-contaminated soils.

In oil-rich regions, the increasing risk of oil spills on soil is largely attributed to intensified extraction and transportation activities. This situation necessitates a focus on the short-term and long-term strength of contaminated soils. While existing literature primarily evaluates the oil-contaminated soils over short-term periods, typically up to 28 days, it is essential to investigate their long-term performance, extending the evaluation period to 365 days. This study addresses the critical gap in understanding the long-term performance of soils contaminated with 4%, 7%, and 10% oil by evaluating the effectiveness of lime stabilization over a one-year period. Laboratory tests were conducted on soils treated with varying lime contents (0%, 3%, 6%, and 9%) and cured for 1, 14, 28, and 365 days. Key performance indicators, including unconfined compressive strength (UCS), California Bearing Ratio (CBR), and durability under wet-dry cycles, were measured. The results demonstrate that a 6% lime content significantly improves long-term UCS, with strength gains ranging from 16.6% to 24.5% while enhancing resilience to wet-dry cycles. Microstructural analyses confirmed the formation of calcium-aluminum-silicate-hydrate (C-A-S-H) phases, contributing to the observed strength and durability improvements. This research underscores the potential of lime stabilization as a sustainable solution for managing oil-contaminated soils, reducing reliance on raw materials, and promoting more sustainable infrastructure development.

Sublethal effects of microplastic and oil co-exposure on biological rates and lipid profiles of keystone Arctic copepods

Microplastics (MPs) and petroleum hydrocarbons are contaminants of emerging concern in the Arctic, but little is known about their co-exposure effects. In this study, we present the first assessment of the sublethal impacts resulting from combined exposure to microplastics and oil in three key Arctic copepod species. Specifically, we investigated the effects of a 5-day exposure to oil alone (1 μL L−1) and in combination with MPs (polyethylene microspheres, 20 μm, 20 MP mL−1) and dispersant (Corexit 9500, 0.05 μL L−1) on the biological functions and lipid profiles of the planktonic copepods Metridia longa, Calanus finmarchicus, and Calanus glacialis. Exposure to oil alone caused a significant reduction (34–58%) in fecal pellet production, but neither microplastics nor dispersant increased the negative effect of oil on fecal pellet production. C. glacialis and C. finmarchicus exposed to the studied pollutants for 5 days produced eggs with delayed hatching and lower hatching success. The highest hatching inhibition (50%) was observed in eggs of C. glacialis exposed to oil plus MPs and dispersant for five days. This indicates that maternal transfer of oil components to eggs negatively affects embryonic development and hatching. Lipid content and fatty acids profiles varied among the studied copepod species but were not affected by the tested pollutants after five days of exposure. By microscopical observation of fecal pellets, ingestion of small oil droplets and MPs was confirmed in all species, but the estimated ingestion of MPs was low (<25 MPs cop−1 d−1, <0.2% of total offered MPs) suggesting avoidance of MP consumption in copepods. Our results indicate that virgin MPs did not increase the toxicity of oil to the studied Arctic copepods under co-exposure conditions, and dispersants can slightly increase certain adverse effects of oil (hatching). However, environmentally relevant concentrations of oil alone can negatively impact Arctic keystone copepods and potentially the biological carbon pump. These findings emphasize the need to reduce petrogenic pollution and the risk of oil spills in the sensitive Arctic ecosystem.

Enhancing Environmental Sensitivity and Vulnerability Assessments for Oil Spill Responses in the Caspian Sea

Oil spills pose significant threats to marine and coastal ecosystems, necessitating advanced methodologies for environmental sensitivity and vulnerability assessments. This study enhances existing frameworks to better manage oil spill risks in the Caspian Sea, a region characterized by its ecological sensitivity and economic dependence on oil extraction. Utilizing the Environmental Sensitivity Index (ESI), we adapted global standards to the unique conditions of the Caspian Sea and built a sensitivity map of the coastline, which later became one of the components of the integral sensitivity map for the entire Caspian Sea, which includes several biotic and abiotic components. We also developed a comprehensive geodatabase incorporating topographic, infrastructural, and hydrodynamic data. Through the sophisticated modeling of oil spill scenarios using the Oil Spill model of the MIKE 21 software (Release 2016) suite, we simulated spills of varying magnitudes to analyze their potential impacts on the marine and coastal environment. The results enabled the creation of vulnerability maps, pinpointing areas at highest risk and facilitating strategic response planning. Our study demonstrates the critical importance of integrating advanced geospatial analyses and dynamic modeling techniques to improve oil spill preparedness and response strategies. The findings of this study suggest that enhanced monitoring and adaptive management strategies are essential for protecting the Caspian Sea from environmental risks posed by its oil industry.

Arctic's hidden hydrocarbon degradation microbes: investigating the effects of hydrocarbon contamination, biostimulation, and a surface washing agent on microbial communities and hydrocarbon biodegradation pathways in high-Arctic beaches

BackgroundCanadian Arctic summer sea ice has dramatically declined due to global warming, resulting in the rapid opening of the Northwest Passage (NWP), slated to be a major shipping route connecting the Atlantic and Pacific Oceans by 2040. This development elevates the risk of oil spills in Arctic regions, prompting growing concerns over the remediation and minimizing the impact on affected shorelines.ResultsThis research aims to assess the viability of nutrient and a surface washing agent addition as potential bioremediation methods for Arctic beaches. To achieve this goal, we conducted two semi-automated mesocosm experiments simulating hydrocarbon contamination in high-Arctic beach tidal sediments: a 32-day experiment at 8 °C and a 92-day experiment at 4 °C. We analyzed the effects of hydrocarbon contamination, biostimulation, and a surface washing agent on the microbial community and its functional capacity using 16S rRNA gene sequencing and metagenomics. Hydrocarbon removal rates were determined through total petroleum hydrocarbon analysis. Biostimulation is commonly considered the most effective strategy for enhancing the bioremediation process in response to oil contamination. However, our findings suggest that nutrient addition has limited effectiveness in facilitating the biodegradation process in Arctic beaches, despite its initial promotion of aliphatic hydrocarbons within a constrained timeframe. Alternatively, our study highlights the promise of a surface washing agent as a potential bioremediation approach. By implementing advanced -omics approaches, we unveiled highly proficient, unconventional hydrocarbon-degrading microorganisms such as Halioglobus and Acidimicrobiales genera.ConclusionsGiven the receding Arctic sea ice and the rising traffic in the NWP, heightened awareness and preparedness for potential oil spills are imperative. While continuously exploring optimal remediation strategies through the integration of microbial and chemical studies, a paramount consideration involves limiting traffic in the NWP and Arctic regions to prevent beach oil contamination, as cleanup in these remote areas proves exceedingly challenging and costly.

Prevention And Mitigation Of Oil Waste In Coastal Areas For Fishing Communities

Oil spills in coastal areas are a serious environmental issue that can cause damage to marine ecosystems, water pollution, and economic losses for fishing communities. This community service project aims to enhance fishermen's understanding of the negative impacts of oil spills and to provide practical skills and knowledge regarding oil waste management. The approach used includes training on the use of absorbent tools, binding chemicals, and localization technologies to handle oil spills. Additionally, the project introduces environmentally friendly technologies to reduce the risk of oil leaks or spills from fishing vessels. The project results indicate a significant increase in the knowledge and skills of the participating fishermen regarding oil waste management. Further discussion reveals the importance of implementing comprehensive coastal area management strategies to prevent and mitigate oil pollution. In conclusion, this project not only successfully achieved its goal of enhancing fishermen's capacity but also offers a replicable model for similar programs in other coastal areas. Therefore, active participation from fishing communities and continuous support from various stakeholders is essential for environmental sustainability and the well-being of coastal communities.

Eco-friendly superhydrophobic sponges for efficient oil-water separation and resource recycling

Owing to the risk of oil spills in the water pollution and human health, it is urgent to exploit the efficient, simple and low-cost materials to treat oily wastewater. Inspired by the native super-wettability surface of lotus leaves, a green, multi-functionality, multi-response and recyclable superhydrophobic material has been established via an one-step dip-coating method based on waste polyurethane sponges (PU), which is expected to settle the treatment problem of oil/water mixture. And the coating system is mainly constituted by a mixture of silicon resin, nano-Fe3O4 and ultrafine expandable graphene (EG), which can act as lowing low surface energy and fabricating the hierarchical micro-/nano-scaled surface roughness. The water contact angle (WCA) of 156.2 ± 1.4° and water sliding angle (WSA) of 8.0 ± 0.5° have triggered a series of skills in water repellency, self-cleaning and anti-fouling. Most of all, the exceptional oil–water separation capabilities have been achieved that the sorption capacity, separation efficiency and flux for light oil can reach 33.2 g/g, 99.5 % and 31,611 L m-1h−1, respectively. Accorded with the intrinsic thermal harvesting ability of Fe3O4 and EG, the excellent photothermal conversion performance has been gained that the temperature of superhydrophobic sponges can reach 68.7 °C in 180 s when the irradiation intensity is 1.2 sunlight, endowing the potential sorption ability of high-viscosity crude oils. Most importantly, the various oil–water separation modes can be also realized that are composed of gravity-driven, magnetism-driven, vacuum-driven and photothermal-driven methods. Except that, the adequate flame retardancy, mechanical durability and chemical stability have been acquired that have raised the high-value-added utilization of modified sponges in fields of environment protection and functional materials.

Kajian Penggunaan Bakteri Bacillus subtilis dalam Penanganan Tumpahan Minyak Mentah

The global demand for energy is driving increased exploration, production and processing of crude oil, increasing the risk of oil spills during these processes and contaminating marine habitats and biota. As hazardous and toxic substances, oil spills require effective and comprehensive management. Bioremediation uses the metabolism of microbes to break down hydrocarbons and convert contaminants into harmless compounds. One species of hydrocarbon-degrading bacteria suitable for bioremediation is Bacillus subtilis. Its adaptability to changes in temperature, salinity, and oxygen levels, as well as its resistance to environmental stress, make it an ideal choice for bioremediation as a sustainable and efficient solution to oil pollution in marine ecosystems. This study aims to explore the potential use of Bacillus subtilis as an alternative for managing crude oil spills, particularly in Indonesian waters.

Temperate Versus Arctic: Unraveling the Effects of Temperature on Oil Toxicity in Gammarids.

Shipping activities are increasing with sea ice receding in the Arctic, leading to higher risks of accidents and oil spills. Because Arctic toxicity data are limited, oil spill risk assessments for the Arctic are challenging to conduct. In the present study, we tested if acute oil toxicity metrics obtained at temperate conditions reflect those at Arctic conditions. The effects of temperature (4 °C, 12 °C, and 20 °C) on the median lethal concentration (LC50) and the critical body residue (CBR) of the temperate invertebrate Gammarus locusta exposed to water accommodated fractions of a fuel oil were determined. Both toxicity metrics decreased with increasing temperature. In addition, data for the temperate G. locusta were compared to data obtained for Arctic Gammarus species at 4 °C. The LC50 for the Arctic Gammarus sp. was a factor of 3 higher than that for the temperate G. locusta at 4 °C, but its CBR was similar, although both the exposure time and concentration were extended to reach lethality. Probably, this was a result of the larger size and higher weight and total lipid content of Arctic gammarids compared to the temperate gammarids. Taken together, the present data support the use of temperate acute oil toxicity data as a basis for assessing risks in the Arctic region, provided that the effects of temperature on oil fate and functional traits (e.g., body size and lipid content) of test species are considered. As such, using the CBR as a toxicity metric is beneficial because it is independent of functional traits, despite its temperature dependency. To the best of our knowledge, the present study is the first to report CBRs for oil. Environ Toxicol Chem 2024;43:1627-1637. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Risk Assessment of Oil Spills along the Coastline of Jiaozhou Bay Using GIS Techniques and the MEDSLIK-II Model

With the increasing global reliance on maritime oil transportation, oil spills pose significant environmental hazards to coastal ecosystems. This study presents a comprehensive quantitative framework for assessing oil spill risks along the Jiaozhou Bay coastline in China. The research begins with an analysis of historical spill data to construct representative oil spill simulation scenarios. The advanced MEDSLIK-II oil spill prediction model is then employed to simulate oil spill trajectories under these scenarios, focusing on key parameters such as oil thickness and mass to evaluate the hazard levels associated with each scenario. Subsequently, the Environmental Sensitivity Index (ESI) is utilized to assess the vulnerability of coastal zones, while Geographic Information System (GIS) techniques are employed for a spatial analysis and visualization of the results. The case study, covering a 26.87 km stretch of the Jiaozhou Bay coastline, reveals 10 high-risk zones with a total length of 8561.2 m. These areas are predominantly characterized by saltwater marshes, brackish water marshes, and inundated low-lying areas, with ESI rankings of 9 and 10, accounting for 24% of the 339 analyzed segments. The modeling results indicate that in the simulated scenarios, oil spills originating from the Huangdao Oil Port and Qianwan Port pose the greatest risks, with potential impacts extending up to 12 km and 15 km along the coastline, respectively. The study highlights the importance of considering multiple factors, including oil spill trajectories, coastal geomorphology, and ecological sensitivity, in comprehensive risk assessments. The proposed framework demonstrates potential for adaptation and application to other coastal regions facing similar oil spill risks, contributing to the advancement of coastal management practices worldwide.

Oil spill risk analysis for the NEOM shoreline

A risk analysis is conducted considering an array of release sources located around the NEOM shoreline. The sources are selected close to the coast and in neighboring regions of high marine traffic. The evolution of oil spills released by these sources is simulated using the MOHID model, driven by validated, high-resolution met-ocean fields of the Red Sea. For each source, simulations are conducted over a 4-week period, starting from first, tenth and twentieth days of each month, covering five consecutive years. A total of 180 simulations are thus conducted for each source location, adequately reflecting the variability of met-ocean conditions in the region. The risk associated with each source is described in terms of amount of oil beached, and by the time required for the spilled oil to reach the NEOM coast, extending from the Gulf of Aqaba in the North to Duba in the South. To further characterize the impact of individual sources, a finer analysis is performed by segmenting the NEOM shoreline, based on important coastal development and installation sites. For each subregion, source and release event considered, a histogram of the amount of volume beached is generated, also classifying individual events in terms of the corresponding arrival times. In addition, for each subregion considered, an inverse analysis is conducted to identify regions of dependence of the cumulative risk, estimated using the collection of all sources and events considered. The transport of oil around the NEOM shorelines is promoted by chaotic circulations and northwest winds in summer, and a dominant cyclonic eddy in winter. Hence, spills originating from release sources located close to the NEOM shorelines are characterized by large monthly variations in arrival times, ranging from less than a week to more than 2 weeks. Similarly, large variations in the volume fraction of beached oil, ranging from less then 50% to more than 80% are reported. The results of this study provide key information regarding the location of dominant oil spill risk sources, the severity of the potential release events, as well as the time frames within which mitigation actions may need to deployed.

Diluted bitumen weathered under warm or cold temperatures is equally toxic to freshwater fish

Canada is one of the main petroleum producers in the world. Through its oil sands exploitation, a viscous bitumen mixed with sand, water, and clay is being produced. This bitumen is so viscous that approximatively 20%–30% of diluent needs to be added to ease transportation, resulting in a mixture called diluted bitumen (dilbit). The transport of dilbit through North America comes with a potential risk for oil spills in freshwater ecosystems at any time of the year. In this study, a mesoscale spill tank was used to study dilbit spills in freshwater to understand the effect of cold (winter-like) vs. warmer (spring- and fall-like) water temperatures on its natural weathering and their toxicity to fathead minnow (Pimephales promelas) embryos. Water samples were collected weekly during two consecutive 35-day experiments ran at either 2 or 15 °C. Each week, fish larvae were exposed for 7 days, and water analysis was performed. Chemical analysis showed that the volatile organic compound, total organic carbon, and polycyclic aromatic hydrocarbon concentrations decreased in both experiments with time, while fish larvae exposed to both temperature settings yielded increased abnormalities, EROD activity, CYP1A, and glutathione S-transferase mRNA expression levels, and decreased heart rate. Importantly, there were no major differences between the temperature regimes on dilbit weathering, highlighting that if a spill occurs in colder waters, it would be equally toxic to organisms. This work provides new data on the potential risk of oil spill for use during response planning and modelling.

Oil droplet fouling on lesser sandeel (Ammodytes marinus) eggshells does not enhance the crude oil induced developmental toxicity

The oil industry's expansion and increased operational activity at older installations, along with their demolition, contribute to rising cumulative pollution and a heightened risk of accidental oil spills. The lesser sandeel (Ammodytes marinus) is a keystone prey species in the North Sea and coastal systems. Their eggs adhere to the seabed substrate making them particularly vulnerable to oil exposure during embryonic development. We evaluated the sensitivity of sandeel embryos to crude oil in a laboratory by exposing them to dispersed oil at concentrations of 0, 15, 50, and 150 µg/L oil between 2 and 16 days post-fertilization. We assessed water and tissue concentrations of THC and tPAH, cyp1a expression, lipid distribution in the eyes, head and trunk, and morphological and functional deformities. Oil droplets accumulated on the eggshell in all oil treatment groups, to which the embryo responded by a dose-dependent rise in cyp1a expression. The oil exposure led to only minor sublethal deformities in the upper jaw and otic vesicle. The findings suggest that lesser sandeel embryos are resilient to crude oil exposure. The lowest observed effect level documented in this study was 36 µg THC/L and 3 µg tPAH/L. The inclusion of these species-specific data in risk assessment models will enhance the precision of risk evaluations for the North Atlantic ecosystems.

Assessing The Risks of Oil Spills and Other Environmental Hazards in Bonny and Ogba/Egbema/Ndoni Local Government Area of Rivers State, Nigeria

This study assessed the emergency and risk drivers in oil exploration activities in Bonny Local Government Area, Rivers State, Nigeria. The descriptive research survey design was adopted for the study. Five research questions were raised to guide the study. The data for the study were collected using a five-point likert scale questionnaire containing a total of 25-items and utilized as a major instrument for the study. In all, three hundred and sixty (360) respondents made up the sample for the study. Arithmetic mean and standard deviation were the major statistical tools used for the data analysis. The results of the study showed that fire outbreak, destruction of crops and farmland, pollution of water bodies and marine lives, destruction of mangroves and increase in the cases of health threatening are the risks and environmental hazards associated with oil exploration in the study areas. The findings of the study also revealed that oil exploration greatly impact the economic, social and cultural wellbeing of the people as well as the health of the people and the environment of the study areas. Based on the above findings, the study recommended among other things, that oil exploration should be operated within stringent regulations designed to safeguard the welfare of employees, the environment, and nearby communities, oil companies operating in the areas should ensure regular monitoring and maintenance of their equipment and facilities so as to reduce the occurrence of pollution due to faulty oil and gas facilities, that oil companies should formulate and practice clearly defined emergency response strategies to manage potential incidents like oil spills or fires effectively.

Characterization of hydrocarbon degraders from Northwest Passage beach sediments and assessment of their ability for bioremediation.

Global warming-induced sea ice loss in the Canadian Northwest Passage (NWP) will result in more shipping traffic, increasing the risk of oil spills. Microorganisms inhabiting NWP beach sediments may degrade hydrocarbons, offering a potential bioremediation strategy. In this study, the characterization and genomic analyses of 22 hydrocarbon-biodegradative bacterial isolates revealed that they contained a diverse range of key alkane and aromatic hydrocarbon-degradative genes, as well as cold and salt tolerance genes indicating they are highly adapted to the extreme Arctic environment. Some isolates successfully degraded Ultra Low Sulfur Fuel Oil (ULSFO) at temperatures as low as -5°C and high salinities (3%-10%). Three isolates were grown in liquid medium containing ULSFO as sole carbon source over 3 months and variation of hydrocarbon concentration was measured at three time points to determine their rate of hydrocarbon biodegradation. Our results demonstrate that two isolates (Rhodococcus sp. R1B_2T and Pseudarthrobacter sp. R2D_1T) possess complete degradation pathways and can grow on alkane and aromatic components of ULSFO under Arctic conditions. Overall, these results demonstrate that diverse hydrocarbon-degrading microorganisms exist in the NWP beach sediments, offering a potential bioremediation strategy in the events of a marine fuel spill reaching the shores of the NWP.

Monitoring Diesel Spills in Freezing Seawater under Windy Conditions Using C-Band Polarimetric Radar

The risk of oil spills in the Arctic is growing rapidly as anthropogenic activities increase due to climate-driven sea ice loss. Detecting and monitoring fuel spills in the marine environment is imperative for enacting an efficient response to mitigate the risk. Microwave radar systems can be used to address this issue; therefore, we examined the potential of C-band polarimetric radar for detecting diesel fuel in freezing seawater under windy environmental conditions. We present results from a mesocosm experiment, where we introduced diesel fuel to a seawater-filled cylindrical tub at the Sea-ice Environmental Research Facility (SERF), University of Manitoba. We characterized the temporal evolution of the diesel-contaminated seawater and sea ice by monitoring the normalized radar cross section (NRCS) and polarimetric parameters (i.e., copolarization ratio (Rco), cross-polarization ratio (Rxo), entropy (H), mean-alpha (α), conformity coefficient (μ), and copolarization correlation coefficient (ρco)) at 20° and 25° incidence angles. Three stages were identified, with notably different NRCS and polarimetric results, related to the thermophysical conditions. The transition from calm conditions to windy conditions was detected by the 25° incidence angle, whereas the transition from open water to sea ice was more apparent at 20°. The polarimetric analysis demonstrated that the conformity coefficient can have distinctive sensitivities to the presence of wind and sea ice at different incidence angles. The H versus α scatterplot showed that the range of distribution is dependent upon wind speed, incidence angle, and oil product. The findings of this study can be used to further improve the capability of existing and future C-band dual-polarization radar satellites or drone systems to detect and monitor potential diesel spills in the Arctic, particularly during the freeze-up season.

Development of An Internet of Things Based Oil Spill Incident Early Warning System

The risk of oil spills are very real, these incident could cause environmental damages and socio-economic losses. These incidents need to be known or realized as early as possible (real-time), to prevent and minimize their environmental and socio-economic impacts. An oil spill early warning system (EWS) based on the Internet of Things (IoT) could be a solution to solve this problem. This research succeeded in developing an EWS called the OSII (Oil Spill Incident Information) System, which allows users to get incident notifications or access the information and response status in real-time wherever they are. The development of this system uses the waterfall method with the stages: requirement analysis, design, implementation, testing and maintenance of the system. Each stage of development is analyzed and discussed in this study. System testing to the OSII System showed quite good results with several suggestions for further development and research.

Interactive Oil Spill Management, Operation and Administration System

This paper presents an oil spill management system that is interactive and real-time. The system uses geo-database and application development modules that are integrated with internet communication systems. It is designed to cover all stages of oil spill management, including before, during, and after an accident. The system can be linked with various satellites, airborne monitoring systems, and ground devices through communication systems to facilitate oil spill early warning, situational analysis, risk analysis, damage analysis, monitoring, and management in real-time. The components of the system include a database, central repository, disaster models, command and control, and communication schemes. This paper illustrates the conjunction of computer software and hardware with a variety of models and technologies for real-time oil spill monitoring and management.

Ecological risk assessment of a coastal area using multi-source remote sensing images and in-situ sample data

Healthy coastal area have high ecological service value. However, because of the uncontrolled utilization of marine resources and the discharge of pollutants, the ecological environments of many coastal areas are faced with ecological risks, such as oil spills and Enteromorpha blooms. Therefore, it is of great significance to monitor and assess the ecological risks in coastal areas. The remote sensing technique can be used to obtain frequent and wide-coverage images of the areas of interest, and has become an effective tool to monitor the ecological risks occurring in coastal areas. In this study, taking Jiaozhou Bay in China as the study area, an innovative ecological risk assessment framework was established using multi-source remote sensing images and in-situ sample data, which fully considers the potential harm of oil spills and Enteromorpha blooms on the ecology of the bay. Specifically, the oil spill risk for Jiaozhou Bay from 2017 to 2019 was identified by a deep learning based method from synthetic aperture radar (SAR) images, and the Enteromorpha bloom risk for the corresponding years was identified by a floating algae index (FAI) threshold method from multi-source optical images. Then, using habitat information and ground observation data about the marine species in the bay, environmental vulnerability maps were generated. Finally, a disaster-causing factors and disaster-bearing factors weighted risk assessment model was developed. The risk source monitoring results show that the occurrence frequency of oil spills in Jiaozhou Bay decreased from 2017 to 2019, while the outbreak intensity of Enteromorpha blooms generally became higher. The ecological risk assessment results reveal that the high risk areas of Jiaozhou Bay are mainly around the transportation regions and the ports, with a higher risk degree in the eastern and southern parts. To support our work, the well-trained oil spill detection network model and some information about the oil spill events that have occurred in Jiaozhou Bay are provided in this paper.

Impacts of crude oil on Arctic sea-ice diatoms modified by irradiance

Anthropogenic climate change is reducing ice and snow thickness in the Arctic. The loss of summer sea ice has led to increased access to Arctic waters and the development of marine resources, which raises the risk of oil spills. Thinning ice and snow also increases irradiance in the upper ocean which is predicted to increase primary productivity, disfavoring shade-adapted sea-ice algae while benefitting phytoplankton and cryopelagic taxa. Studies have confirmed the lethality of crude oil and its distillates to Arctic phytoplankton; less well-constrained are the sublethal impacts to sea-ice algae in combination with other drivers. This study investigates the combination of two drivers, crude oil exposure and irradiance, on the growth rate and maximum cell concentration of four sea-ice diatoms (Attheya septentrionalis, Fragilariopsis cylindrus, and two strains of Synedropsis hyperborea) isolated from landfast sea ice near Utqiaġvik, Alaska. Crude oil inhibition of growth was complex and dependent on species and irradiance level. A. septentrionalis was generally tolerant to crude oil exposure, but toxicity was enhanced at the highest irradiance. The cryopelagic taxon, F. cylindrus, exhibited strong growth inhibition at TPH concentrations greater than approximately 6 mg L−1. Growth rates of S. hyperborea strains were stimulated at low concentrations of oil at all light levels. A simple numerical model was used to simulate an oil spill under varying snow depths to follow composition of a mock community comprised of these four isolates across a spring season. Results highlight that the reduction of algal biomass accumulation and the community composition change following a crude oil spill are more severe in a simulated low-snow spring, due to the relative sensitivity of F. cylindrus. We show that a brighter Arctic, which is predicted to increase the relative importance of cryopelagic taxa like F. cylindrus, may render the Arctic ecosystem more vulnerable to crude oil spills.

Evaluation of human error in oil spill risk in tanker cargo handling operations.

Cargo handling operations on board tankers pose a significant threat to the cleanliness and health of the ocean ecosystem. Incidents originating from these operations are often attributed to human error, as widely acknowledged. Therefore, it is crucial to control the human factor involved in these operations to enhance ship safety and foster a sustainable, clean marine environment. To tackle this problem, this paper presents a novel model that identifies the causal factors behind oil spills resulting from crew failure in these operations. To attain this, fuzzy Bayesian network (FBN) approach is used in this study to analyse the probabilistic correlations among the causal elements that are disclosed qualitatively and quantitatively. Sensitivity analyses and validation procedures are carried out to enhance the accuracy of results. Eliminating errors in cargo calculation is of paramount importance as research has shown that such errors lead to the largest impact on spill during loading and discharging (L&D) operations. The study's findings offer valuable insights into the causes of L&D operation-related spills. Ship management companies, the loss-prevention division of Protection and Indemnity Clubs (P&I), and regulatory bodies may employ the research results to prevent spill repetitions and protect the marine environment.