ABSTRACT

Oil spilled into the marine environment undergoes a process of photodegradation when exposed to sunlight. Photochemically-degraded oil is highly complex and poses a hazard to marine organisms. As the circumpolar north loses ice at an unprecedented rate, oil drilling in the Arctic is forecasted to increase, raising the possibility of a major oil spill in a remote cold region. Surface collection agents, or "chemical herders" have gained attention recently for the ability to thicken slicks to allow in-situ burning in ice-associated areas for over 90% oil mass removal. However, little is known about the formation of dissolved residues stemming from this process, how dissolved residues are transformed in the presence of sunlight, and what impacts may occur on susceptible marine organisms. This project will advance our understanding of how oil is transformed into a water-soluble form following combustion; it will assess the chemical character and biological uptake of the residues as they weather in Arctic waters. The project will involve residue extraction and analysis at the University of New Orleans and National High Magnetic Field Laboratory. The results will guide future oil spill response and contingency planning.

The longitudinal dissolution rates governing hydrocarbon-derived dissolved organic matter, especially those deriving from oxygenation, remain understudied in the Arctic and Subarctic domains with regard to treatment options of oiled water following a maritime point release. Extreme seasonal swings in photoperiods further complicate this process via photodissolution and may have broad impacts on bioaccumulation potential in susceptible marine organisms such as mussels, Mytilus trossulus. Surface collection agents (chemical herders) have gained popularity recently for the ability to thicken oil prior to in-situ burning, a process that is capable of removing >90% of oil from the surface. However, little is known about the formation of dissolved residues stemming from this process and the chemical character as these dissolved residues weather. This project will assess these factors using two new emerging technologies, fluorescence excitation emission spectra (EEMs) coupled with Parallel Factorial Analysis (PARAFAC) and Fourier Transformation Ion Cyclotron Mass Spectrometery (FT-ICR MS). Bench-scale simulations will be conducted at the University of Alaska Anchorage with ANS Crude oil, two herder formulations (OP-40 and ThickSlick), and mussels collected from Resurrection Bay, Alaska. Residues are extracted and EEMs analyzed at the University of New Orleans, with FT-ICR MS analyses conducted at the National High Magnetic Field Laboratory. This study will fund PI Tomco and one graduate student assistant to travel to New Orleans, LA and Tallahassee, FL. This will lead to broader integration of advanced spectroscopic and spectrometric techniques at the PI's home institution and increase institutional capacity to compete for external research support.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

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