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Spectroscopic techniques including X-ray fluorescence (XRF) and attenuated total reflectance – Fourier transform infrared spectroscopy (ATR-FTIR) are used to examine oil residues persisting on shorelines in Prince William Sound that originate from the 1989 Exxon Valdez oil spill and oil released as a consequence of the 1964 Great Alaska earthquake. When coupled to classification models, ATR-FTIR and XRF spectral data can be used to distinguish between the two sources of oil with 92% and 86% success rates for the two techniques respectively. Models indicate that the ATR-FTIR data used to determine oil source includes the C O stretch, the twisting-scissoring of the CH2 group, and the C C stretch. For XRF data, decision tree models primarily utilize the abundance of nickel and zinc present in the oil as a means to classify source. This approach highlights the utility of rapid, field-based spectroscopic techniques to distinguish different inputs of oil to coastal environments.

When glaciers melt, they contribute significant quantities of water and ice, sediments and dissolved chemicals to the ocean. Recent efforts in Greenland and Antarctica show that both the delivery of materials to the marine environment, as well as local changes to ocean circulation induced by the input of freshwater, have the potential to profoundly impact key processes such as primary and secondary production, and by extension the biological carbon pump. Yet, extensive knowledge gaps remain about the chemical composition of glacial meltwater runoff at the ice-ocean interface, the spatial extent of its influence within coastal environs, and the mechanisms by which glaciers affect surface marine microbial communities. Nowhere are these knowledge gaps more prominent than in the Canadian Arctic Archipelago (CAA) – a region where the role of glacial meltwater in marine biogeochemical cycles is almost fully unexplored – despite the fact that it is a hotspot for glacial retreat and meltwater runoff to the ocean. Here, we conduct a regional comparative study of the nearshore coastal zone of glaciated and non-glaciated fjords and of multiple glaciers of varying type (land-terminating, tidewater) and size draining large ice caps. Our study site in Jones Sound, NU is home to the Inuit hamlet of Grise Fiord. Traditional knowledge from this community indicates that the termini of tidewater glaciers in this region are rich in wildlife, providing habitual hunting grounds for its citizens. Guided by this information, we combined shipboard measurements of temperature, salinity, turbidity, and chlorophyll a with bottle samples characterizing oxygen, sediment, carbon, nutrient, metal, and biological community composition to elucidate how these properties evolve with distance from the shore. Results from this study substantially further our understanding of glacier-ocean impacts in the CAA and beyond, while also providing data critical to accurate future projections of high-latitude marine ecosystem productivity and function in this era of climate change.

Oil residues originating from the Deepwater Horizon (DWH) incident persist on Gulf of Mexico beaches alongside oil from offshore industrial activity, natural seepage, and asphalt from parking lots and roads. To determine the primary differences in the chemical composition of these oil residues, a variety of samples were collected from beaches from Florida to Alabama over a two-year period from 2015 to 2017. Bulk chemical characteristics of the oil residues were examined via gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC–MS), as well as thin layer chromatography with flame ionization detection (TLC-FID), and attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR). These bulk chemical analyses revealed features unique to the different sample types, expanding our understanding of the chemical composition and variability of persistent oil residues, and providing a means to detect and monitor their long-term fate in the coastal environment.