| NSF Org: |
OCE Division Of Ocean Sciences |
| Recipient: |
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| Initial Amendment Date: | August 1, 2016 |
| Latest Amendment Date: | August 1, 2016 |
| Award Number: | 1634999 |
| 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: | September 1, 2016 |
| End Date: | August 31, 2019 (Estimated) |
| Total Intended Award Amount: | $98,859.00 |
| Total Awarded Amount to Date: | $98,859.00 |
| 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: |
266 Woods Hole Rd Woods Hole MA US 02543-1598 |
| 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): | 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
While the release of petroleum hydrocarbons into the ocean is recognized as an environmental and human hazard, a recent study has estimated that on an annual basis, the release of natural hydrocarbons by a single phytoplankton group (cyanobacteria) contributes at least ten times more total hydrocarbon to the surface ocean. This project will be the first in-depth study of the latent biogeochemical cycling of this huge pool of biogenic hydrocarbons. Using field studies, laboratory incubations of cyanobacteria, and state-of-the art chemical analysis, the researchers will examine the molecular structures, rates and mechanisms of production and removal, and the environmental conditions that control the cycling of this major pool of oceanic hydrocarbons. The results of this study will reveal significant new knowledge for improved understanding of a major carbon cycle in the ocean. Additionally, data could indicate a role for cyanobacterial hydrocarbons in preparing natural marine bacteria to respond to, and degrade petroleum spills, as well as a possible atmospheric impact (e.g. cloud formation) resulting from air-sea exchange of certain components of the hydrocarbon pool.
This project will support undergraduate and graduate students, a postdoctoral investigator, and a new faculty member, and will engage participants from minority-serving institutions in California and North Carolina. Plans are also included to establish links with oil spill and biofuel researchers in order to evaluate additional practical applications for the data resulting from this study.
The annual production of 308,000,000 - 771,000,000 tons of hydrocarbons by cyanobacteria has recently been reported and is a factor of 10 larger than marine petroleum hydrocarbon input from spills and natural seeps. Consequently, these biogenic hydrocarbons almost certainly have significant implications for the carbon cycle and the bacterial community composition in the ocean but have never been the subject of rigorous study. This project will investigate the distribution, partitioning, and cycling of biogenic hydrocarbons in the ocean, focusing on the abundance and molecular diversity of biogenic hydrocarbons in relation to cyanobacterial populations; the extent to which volatilization to the atmosphere acts as a sink for biogenic hydrocarbons; and the rate at which hydrocarbons are produced by cyanobacteria and consumed by hydrocarbon-degrading bacteria. Field studies across natural gradients in phytoplankton community structure and abundance will employ state of the art chemical analysis to evaluate the distribution of biogenic hydrocarbons, and together with incubation experiments will determine quantitative rates for biogenic hydrocarbons cycling in the surface ocean. Laboratory studies will augment field studies by assessing hydrocarbon production and loss mechanisms under carefully controlled laboratory conditions. Together, the project will obtain a quantitative understanding of this important component of the oceanic carbon cycle.
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.
Microscopic photosynthetic organisms in the ocean called cyanobacteria are so numerous that blooms can be seen from space by satellites. Laboratory experiments suggest that cyanobacteria produce millions of tons of hydrocarbons, chemicals containing carbon and hydrogen, which have the potential to greatly affect the chemistry of our oceans and atmosphere. These hydrocarbons can serve as an energy source for other ocean bacteria that may be important in degrading oil spills. They also have the potential to evaporate into the atmosphere where they can impact air quality, cloud formation and precipitation, and climate.
This project aimed to investigate how these hydrocarbons cycle through the marine environment. We were interested in four questions: 1) How much of these hydrocarbons are found in ocean water? 2) How quickly do bacteria consume these hydrocarbons? 3) How much of these hydrocarbons evaporates into the atmosphere? 4) Do these hydrocarbons sustain a population of other bacteria that can then degrade oil spills? In particular, our group’s role in this collaborative work was to measure hydrocarbons in the air and to examine the relationship between the measured hydrocarbons and the cyanobacteria present in different parts of the ocean. To accomplish this, we collected air and water samples during a three-week research cruise aboard the R/V/ Neil Armstrong in 2017 in the North Atlantic Ocean and measured hydrocarbon concentrations and counted cells of different species of cyanobacteria.
We did not find evidence of the major hydrocarbons produced by cyanobacteria in our air samples, which means that the vast majority of these hydrocarbons remains in the water. However, we did see evidence that a species of cyanobacteria called Synechococcus may produce large amounts of a hydrocarbon called toluene that evaporates into the atmosphere. Toluene is highly reactive with other chemicals in the air and can form tiny particles called secondary organic aerosols. These aerosols have the potential to increase cloud formation over the ocean, which can impact precipitation patterns and climate, and can negatively impact human health if they are transported to populated downwind areas.
This work involved several undergraduate students from an undergraduate university that serves a high number of first generation college students. The students not only received training in the use of scientific instrumentation and data analysis, but were also able to present their work at regional and national conferences, making contacts with potential employers and graduate school advisors, and to publish their work as undergraduate theses and as co-authors on future peer-reviewed manuscripts.
Last Modified: 03/11/2020
Modified by: Robert F Swarthout
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