Understanding the fate of spilled oil in cold environments is essential for oil spill response in Arctic areas. The potential for oils to adhere to sea ice and mechanical skimmers can significantly impact the success of oil spill response and influence the fate of oil in the marine environment. Therefore, the affinity of oil to sea ice and skimmer material was quantified experimentally for three different types of oils at various degrees of weathering. Contact angle measurements of crude oil droplets were performed on the top of and under sea ice and polyethylene-based skimmer material, being submerged in seawater (−2 °C). In addition, “dip- and refloat” tests were performed to quantify the adhesion and study the re-floating process of oil from sea ice at −2 °C (moist ice) and −20 °C (cold dry ice), and from a skimmer material prior to and subsequently to its submersion in seawater (−2 °C). The results indicated limited interaction of oils with sea ice submerged in seawater, but a strong affinity of oils towards polyethylene-based skimmer material. | Study on how oil type and weathering of crude oils affect interaction with sea ice and polyethylene skimmer material | publishedVersion

Antarctic trace element records could provide important insights into the impact of human activities on the environment over the past few centuries. In this study, we investigated the atmospheric concentrations of 14 representative heavy metals (Al, As, Cd, Co, Cu, Fe, K, Mg, Mn, Pb, Sb, Sr, Tl and V) from 174 samples collected in a 4-m snow pit at Dome Argus (Dome A) on the East Antarctic Plateau, covering the period from 1950 to 2016 A.D. We found great variability in the annual concentration of all metals. The crustal enrichment factors suggest that the concentrations of some heavy metals (Cd, Sb, Cu, As and Pb) were likely influenced by anthropogenic activities in recent decades. An analysis of source regions suggests that heavy metal pollution at Dome A was largely caused by human activities in Australia and South America (e.g. mining production, leaded gasoline). Based on the relationship between the trace elements fluxes and sea ice concentration (SIC), sea surface temperature (SST) and annual mean air temperature at 2 m above the ground (T₂ₘ), our analysis shows that deposition and transport of atmospheric aerosol at Dome A were influenced by circum-Antarctic atmospheric circulations.

Climate change has become one of the greatest concerns of the past few decades. In particular, global warming is a growing threat to the Canadian high Arctic and other polar regions. By the middle of this century, an increase in the annual mean temperature of 1.8 °C–2.7 °C for the Canadian North is predicted. Rising temperatures lead to a significant decrease of the sea ice area covered in the Northwest Passage. As a consequence, a surge of maritime activity in that region increases the risk of hydrocarbon pollution due to accidental fuel spills. In this review, we focus on bioremediation approaches on Arctic shorelines. We summarize historical experimental spill studies conducted at Svalbard, Baffin Island, and the Kerguelen Archipelago, and review contemporary studies that used modern omics techniques in various environments. We discuss how omics approaches can facilitate our understanding of Arctic shoreline bioremediation and identify promising research areas that should be further explored. We conclude that specific environmental conditions strongly alter bioremediation outcomes in Arctic environments and future studies must therefore focus on correlating these diverse parameters with the efficacy of hydrocarbon biodegradation.

Polyaromatic phenanthrene (Phe) and benzo[a]pyrene (BaP) are highly toxic, mutagenic, and carcinogenic contaminants widely dispersed in nature, including saline environments. Polyextremotolerant Rhodotorula mucilaginosa EXF-1630, isolated from Arctic sea ice, was grown on a huge concentration range -10 to 500 ppm- of Phe and BaP as sole carbon sources at hypersaline conditions (1 M NaCl). Selected polycyclic aromatic hydrocarbons (PAHs) supported growth as well as glucose, even at high PAH concentrations. Initially, up to 40% of Phe and BaP were adsorbed, followed by biodegradation, resulting in 80% removal in 10 days. While extracellular laccase, peroxidase, and un-specific peroxygenase activities were not detected, NADPH-cytochrome c reductase activity peaked at 4 days. The successful removal of PAHs and the absence of toxic metabolites were confirmed by toxicological tests on moss Physcomitrium patens, bacterium Aliivibrio fischeri, human erythrocytes, and pulmonary epithelial cells (A549). Metabolic profiles were determined at the midpoint of the biodegradation exponential phase, with added Phe and BaP (100 ppm) and 1 M NaCl. Different hydroxylated products were found in the culture medium, while the conjugative metabolite 1-phenanthryl-β-D-glucopyranose was detected in the medium and in the cells. Transcriptome analysis resulted in 870 upregulated and 2,288 downregulated transcripts on PAHs, in comparison to glucose. Genomic mining of 61 available yeast genomes showed a widespread distribution of 31 xenobiotic degradation pathways in different yeast lineages. Two distributions with similar metabolic capacities included black yeasts and mainly members of the Sporidiobolaceae family (including EXF-1630), respectively. This is the first work describing a metabolic profile and transcriptomic analysis of PAH degradation by yeast.

Sea ice loss is opening shipping routes in Canada's Northwest Passage, increasing the risk of an oil spill. Harnessing the capabilities of endemic microorganisms to degrade oil may be an effective remediation strategy for contaminated shorelines; however, limited data exists along Canada's Northwest Passage. In this study, hydrocarbon biodegradation potential of microbial communities from eight high Arctic beaches was assessed. Across high Arctic beaches, community composition was distinct, potential hydrocarbon-degrading genera were detected and microbial communities were able to degrade hydrocarbons (hexadecane, naphthalene, and alkanes) at low temperature (4 °C). Hexadecane and naphthalene biodegradation were stimulated by nutrients, but nutrients had little effect on Ultra Low Sulfur Fuel Oil biodegradation. Oiled microcosms showed a significant enrichment of Pseudomonas and Rhodococcus. Nutrient-amended microcosms showed increased abundances of key hydrocarbon biodegradation genes (alkB and CYP153). Ultimately, this work provides insight into hydrocarbon biodegradation on Arctic shorelines and oil-spill remediation in Canada's Northwest Passage.

As climate change brings reduced sea ice cover and longer ice-free summers to the Arctic, northern Canada is experiencing an increase in shipping and industrial activity in this sensitive region. Disappearing sea ice, therefore, makes the Arctic region susceptible to accidental releases of different types of oil and fuel pollution resulting in a pressing need for the development of appropriate scientific knowledge necessary to inform regulatory policy formulation.In this study, we examine the microstructure of the surficial layers of sea ice exposed to oil using X-ray microtomography. Through analysis, 3D imaging of the spatial distribution of the ice's components (brine, air, and oil) were made. Additional quantitative information regarding the size, proximity, orientation, and geometry of oil inclusions were computed to ascertain discernable relationships between oil and the other components of the ice. Our results indicate implications for airborne remote sensing and bioremediation of the upper sea ice layers.

The durability of plastics in the marine environment has led to concerns regarding the pervasiveness of this debris in remote polar habitats. Microplastic (MP) enrichment in East Antarctic sea ice was measured in one ice core sampled from coastal land-fast sea ice. The core was processed and filtered material was analyzed using micro Fourier-Transform Infrared (μFTIR) spectroscopy. 96 MP particles were identified, averaging 11.71 particles L⁻¹. The most common MP polymers (polyethylene, polypropylene, and polyamide) were consistent with those most frequently represented in the majority of marine MP studies. Sea-ice MP concentrations were positively related with chlorophyll a, suggesting living biomass could assist in incorporating MPs in sea ice. Our preliminary results indicate that sea ice has the potential to serve as a reservoir for MP debris in the Southern Ocean, which may have consequences for Southern Ocean food webs and biogeochemistry.

Due to the effects of heightened warming in the Arctic, there has been an urgency to develop methods for detecting oil in (or under) sea ice, owing to increasing potential for oil exploration and ship traffic in the more accessible Arctic regions. To test the potential for radar utilizing the normalized radar cross section (NRCS) of the sea ice, an oil-in-ice mesocosm experiment was performed. Throughout the experiment, corn oil was used as a surrogate for medium crude oil, to assess oil movement tendencies in sea ice, and the resultant impact on the complex permittivity through measurement and modelling techniques. We performed a modelling study to establish the effects of corn oil on the NRCS of sea ice. The oil presence in the sea ice increased the temperature and reduced the salinity of the sea ice, thereby lowering its complex permittivity and modeled NRCS when compared to control sea ice.