| NSF Org: |
OCE Division Of Ocean Sciences |
| Recipient: |
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| Initial Amendment Date: | January 19, 2018 |
| Latest Amendment Date: | March 3, 2023 |
| Award Number: | 1756667 |
| Award Instrument: | Standard Grant |
| Program Manager: |
Henrietta Edmonds
hedmonds@nsf.gov (703)292-7427 OCE Division Of Ocean Sciences GEO Directorate for Geosciences |
| Start Date: | March 1, 2018 |
| End Date: | February 29, 2024 (Estimated) |
| Total Intended Award Amount: | $199,440.00 |
| Total Awarded Amount to Date: | $199,440.00 |
| Funds Obligated to Date: |
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| History of Investigator: |
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| Recipient Sponsored Research Office: |
438 ACADEMY ST BOONE NC US 28608-0001 (828)262-7459 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
525 Rivers St Boone NC US 28608-2174 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): |
BIOLOGICAL OCEANOGRAPHY, Chemical Oceanography |
| Primary Program Source: |
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| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.050 |
ABSTRACT
This research project addresses the fate of hydrocarbons that enter the ocean, using geological oil seeps as a natural scientific laboratory. The key issues of intellectual merit that will be addressed focus on the development and application of methodology to determine how the chemical properties of hydrocarbon molecules dictate whether they will be trapped in the ocean's interior or find their way to the atmosphere. The research will further follow the fate of these molecules in the ocean's interior, determining how the ocean's bacterial population responds, and the extent to which responding bacteria will degrade these molecules. The broader impacts of this research will include the training of undergraduate and graduate students in scientific research and at-sea oceanographic training, as well as the dissemination of findings to policy makers striving to understand the fate and effects of hydrocarbons in the ocean.
Hydrocarbons enter the ocean through a combination of natural seepage, anthropogenic discharge and biological production, with profound impacts on ocean biogeochemistry, ecology, and the atmosphere. This research project addresses the chemical and biological processes affecting water-soluble alkanes in the ocean, using natural seeps to study their fluxes, partitioning between ocean and atmosphere, and the bacterial response to their input. The intellectual merit of this research pertains to the behavior of highly volatile hydrocarbons, a class that is abundant in petroleum reservoirs and many crude and refined products, but is poorly understood in the ocean. Volatile hydrocarbons display distinct behaviors compared with traditional oil in that they will partition to seawater or the atmosphere depending on their molecular structure and the context by which they enter the ocean, a combination of characteristics unsuitable for traditional fate and transport models that govern our understanding of liquid oil. This research project addresses this gap in knowledge through a plan to study volatile, water-soluble hydrocarbons in the context of natural seepage, focusing on key questions about their transport and fate, and the ocean?s microbial response. Two key questions include: 1) What factors control the partitioning of water-soluble alkanes between water and the atmosphere at natural seeps, and how does this affect their availability to microbes? 2) What genomic and metabolic factors enable the microbial response to the input of water-soluble alkanes and how does the microbial response vary with regional oceanographic and geologic factors such as proximity to and flux from natural seepage? The hypotheses that result from these questions will be tested through a series of oceanographic and laboratory-based experiments designed around natural oil seeps in the Pacific and in the Gulf of Mexico. The results of these studies promise to inform our understanding of the transport, fate, and effects of water-soluble alkanes in the ocean.
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.
PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
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PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
Natural oil seeps are found throughout the world's oceans. These seeps are a constant source of oil to the water column and form sheens at the water surface. They support marine ecosystems by providing a source of carbon and other elements for marine microbes, which, in turn, support higher organisms. Measuring the amount of oil coming from natural oil seeps is challenging and has previously relied on aerial or satellite observations of surface sheens. Our project focused on developing a new method to measure the rate of oil seepage and understanding the impacts that this oil has on microbial populations. To accomplish this, we designed an uncrewed aerial vehicle (UAV) based air sampling method to measure concentrations of oil chemicals in the air above natural oil seeps and collected fresh oil at the seafloor using the Alvin deep-sea submersible at seep locations in the Gulf of Mexico. Using these two groups of samples we were able to quantify the amount of oil being released. We also collected water samples to investigate the impact of the oil on the microbes present throughout the water column.
Intellectual merit:
Our work is the first to use our UAV vertical profiling method to estimate oil release rates from natural seeps. Future use of the methods we developed will allow for additional ground truthing of estimates relying exclusively on satellite and aerial survey observations and the uncertain relationships between oil sheen color and oil thickness. Greater accuracy in estimates of natural oil seep emission rates will enhance our understanding of the fate of petroleum hydrocarbons in the water column at seep sites and the role of these hydrocarbons in oceanic nutrient cycling in impacted areas.
The UAV based sampling methodology developed and validated in our work provides a useful tool for estimating emission fluxes from other diffuse sources. This could have implications for quantifying transport of pesticides to non-target areas or hazardous air pollutants to downwind population centers.
Broader impacts:
This project allowed for multiple educational and training opportunities for students at Appalachian State University. We created a laboratory experience for undergraduate students in a Global Biogeochemical Cycles course that leverages the methodology developed. Over 40 students per course explore fundamental concepts of atmospheric emissions and transport during this lab and measure atmospheric fluxes of pollutants. They then use these calculations in a simple biogeochemical model to estimate impacts on downwind locations.
The project has also provided rich datasets for nine undergraduate research students at to use in capstone research courses in chemistry and environmental science. These students had the opportunity to present their work at national and regional conferences and network with potential graduate school advisors and employers.
Last Modified: 09/04/2024
Modified by: Robert F Swarthout
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