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Methane in OMZs
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2017
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Sally Ride
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Project Title: |
Microbial processes of pelagic anaerobic methane cycling in oxygen minimum zones |
Project Status: |
Submitted |
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Principal Investigator: |
Frank J. Stewart, MSU |
Project Institution: |
GaTech |
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Project ID: |
104979 |
Version #: |
8 |
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Date Submitted: |
8/9/2015 3:31:00 PM |
Created By: |
Frank J. Stewart |
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Date Last Modified: |
10/7/2016 10:31:00 AM |
URI Serial #: |
None |
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Funding Agencies: |
NSF/OCE/BIO - 1558916 - Funded |
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Summary of Field Work: |
Recent evidence suggests that marine oxygen minimum zones (OMZs) support microorganisms that couple pelagic methane consumption to processes of nitrogen (N2) loss. However, the metabolic pathways and microbial taxa responsible for these transformations are just beginning to be characterized, and the full extent of pelagic microbial methane cycling in OMZs remains unconstrained. In addition, the role of denitrification-dependent methane oxidation as a potential 3rd route of oceanic nitrogen loss (in addition to classical denitrification and anammox) has not been quantified. Here, we propose to investigate the diversity, activity, and global distribution of microorganisms mediating methane-nitrogen cycle linkages in OMZs. We focus primarily on characterizing pelagic members of the candidate division NC10, a recently described bacterial group that couples methane oxidation to a unique pathway of nitrite-dependent N2 and O2 production. Recent molecular studies in our lab suggest that NC10 bacteria are present and active in nitrite-replete anoxic OMZs of the Eastern Tropical Pacific. Here, we aim to quantify the environmental drivers shaping NC10 distributions in OMZs, measure rates of NC10 methane oxidation and N2 production in OMZs, and analyze the metabolic gene content and evolutionary history of pelagic NC10 bacteria relative to those from other habitats.
We propose a combination of meta-omic (community DNA and RNA) sampling, single-cell genomics, shipboard stable isotope experiments, and microbial enrichments to characterize anaerobic methane cycling in the permanent OMZ of the Eastern Tropical North Pacific (ETNP) and the hypoxic “dead zone” in the Gulf of Mexico (GOM). Results will be contextualized relative to molecular surveys of existing samples from the Eastern Tropical South Pacific OMZ (Chile/Peru) and three silled anoxic basins (Golfo Dulce off Costa Rica; Cariaco Basin off Venezuela; Soledad Basin off Baja), thereby establishing a comparative framework for understanding the diversity and ecology of pelagic anaerobic-methane oxidizer communities in diverse low-oxygen regions.
Fieldwork will consist of two cruises, one to the ETNP in early summer 2016 and one to the GoM in summer 2017. We have worked at both sites in prior years in support of other OMZ-related projects. We propose sampling in the ETNP OMZ at 10-15 stations along two transects starting roughly from Manzanillo, Mexico and running southeast-northwest along the coast (~19-24°N, 106-116°W) and northeast-southwest off the coast (~14-18°N, 106-115°W). Proposed sampling in the GOM will span 5-10 stations on an east-west transect through the hypoxic zone on the Louisiana shelf (~28-29°N, 89-94° W). At each station, general water column parameters will be assessed via vertical depth surveys using a CTD equipped with sensors for fluorometry, PAR, and dissolved oxygen. Seawater collections for DNA, RNA, and microscopy samples and chemical measurements (of methane, nitrate, nitrite, ammonium, concentrations) will be done via rosette casts to discrete depths spanning the oxycline and suboxic zones. More extensive sampling will be done at ~3-5 process stations. At these sites, additional seawater samples will be collected for shipboard stable isotope and microcosm experiments to measure methane oxidation and nitrogen transformation rates and community transcriptional responses to methane and nitrogen additions. These seawater collections will also be used as inocula for incubations to enrich for denitrification-dependent anaerobic methane oxidizers. We therefore anticipate ~6-10 CTD-rosette casts (~24 hrs) per process station (initial CTD profile + nutrient collection + RNA/DNA casts) and 1-2 casts (~4 hrs) per non-process station. |
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Summary of Facility Requirements: |
The proposed shipboard microcosm experiments will involve maintaining temperature and ambient light at in situ levels. To do so, we will require access to a dedicated cold van that can be kept dark during the incubations, though external shading could also be used to regulate light levels. In addition, the project requires access to a rosette and CTD equipped with sensors for fluorometry, PAR, and dissolved oxygen. We will likely also mount high-resolution STOX oxygen sensors to the CTD, in addition to sensors available via UNOLS. We will need wet lab bench and storage space (estimated 30-40 sq ft) for filtering and preserving rosette-based water samples, as well as space to put a liquid nitrogen dewar for flash-freezing and temporarily storing RNA samples, and pressurized gases for experiments (methane, helium, argon). RNA samples can then be moved into a -80C freezer (if available) for longer-term storage. Access to a - 20C freezer and 4C refrigerator will be needed for storing DNA samples, reagents, and samples for enrichment cultures. |
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Summary of other requirements and comments: |
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Type of Request: |
Collaborative Ship Use |
Request Status: |
Submitted |
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Request ID: |
1007993 |
Created By: |
Frank J. Stewart |
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Date Last Modified: |
10/7/2016 10:31:00 AM |
Date Submitted: |
8/9/2015 3:31:00 PM |
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Year: |
2017
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Ship/Facility: |
Sally Ride
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Optimum Start Date:
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5/1/2017 |
Dates to Avoid: |
We would like to avoid sampling in the ETNP from October-April (Winter), due to teaching requirements. We also strongly prefer to sample earlier (May) in the summer rather than later to avoid the potential for hurricanes. |
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Earliest Start Date: |
4/24/2017 |
Multi-Ship Op: |
No |
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Latest Start Date: |
6/14/2017 |
Other Ship(s): |
N/A |
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Operating Days Needed: |
Science Days |
Mob Days |
De-Mob Days |
Estimated Transit Days |
Total Days |
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14 |
2 |
2 |
8 |
26 |
Repeating Cruise?
(within same year) |
No |
Interval: |
N/A |
# of Cruises: |
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Description of Repeating cruise requirements: |
N/A |
Justification/Explanation for ship choice, dates,
conflicts, number of days & multi-ship operations: |
R/V Sally Ride is based out of San Diego, the US port closest to the ETNP. Ideally, we would like to avoid sampling in the ETNP from October-April (Winter), due to teaching requirements. However, we may be able to accommodate winter sampling if absolutely necessary. We also strongly prefer to sample earlier (May) in the summer rather than later to avoid the potential for hurricanes. |
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Short Description of Op Area
for use in schedules: |
ETNP OMZ |
| Description of Op Area: |
Eastern Tropical North Pacific oxygen minimum zone (OMZ), off Colima Mexico, south of Baja |
| Op Area Size/Dia.: |
600 |
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Lat/Long |
Marsden Grid |
Navy Op Area |
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Beginning
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Ending
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Show Degrees Minutes |
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Foreign Clearance Required? |
Yes |
Coastal States:
Mexico |
 Important Info on Foreign Research Clearances
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Are you or any member in your science party bringing in any science equipment items which are regulated for export by the International Traffic in Arms Regulations (ITAR) and/or the Export Administration Regulations (EAR)?
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No |
If yes, have you applied for the necessary permits through your export control office?
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No |
| Questions about ITAR/EAR regulations?
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Comments about foreign clearance requirements or
description of any other special permitting requirements
(e.g., MMPA, ESA, IHA, Marine Sanctuaries, etc.) |
N/A |
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Requested Start Port |
Intermediate Port(s) |
Requested End Port |
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San Diego, CA, USA |
None, , None, |
San Diego, CA, USA |
Explanation/justification for requested
ports and dates of intermediate stops
or to list additional port stops |
San Diego is the port closest to the study area. |
Important Info on Working in Foreign Ports
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Chief Scientist: |
Frank J. Stewart, MSU |
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# in Science Party |
8 |
# of different science teams |
3 |
# Marine Technicians to be
provided by ship operator:
(include in science party total)
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2 |
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Explanation of Science Party Requirements and Technician Requirements |
Science party: 2 from Co-I Jen Glass lab, 3 from collaborator Bo Thamdrup lab, 3 from PI Stewart lab. Two technicians are requested to deploy and operate the CTD-rosette during 24-hr ops. Additional party members are required for water collection and processing and shipboard experiments. |
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 Dynamic Positioning | ADCP | Multibeam | Seismic |
| Dredging/Coring/Large Dia. Trawl Wire | Stern A-frame | Fiber Optic (.681) | 0.680 Coax Wire |
| SCUBA Diving | Radioisotope use - briefly describe | NO Radioisotope use/Natural level work | Other Operator Provided Inst. - Describe |
| 0 PI-Provided Vans - briefly describe | MOCNESS | | |
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Explain Instrumentation or Capability
requirements that could affect choice
of ship in scheduling. |
We will need access to a dedicated cold van and radioisotope van for shipboard experiments and sample processing.
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Explain Major Ancillary Facilities
Requirements and list description
and provider for "other" systems. |
We will need access to a dedicated cold van and radioisotope van for shipboard experiments and sample processing. |
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