Table of Contents

• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

Physical and geochemical data measured in April and October of 2009 from the water column, porewater, and sediments of the Cape Fear River Estuary (located at the southeast of North Carolina; 34 N 78 W depth range 1 to 20 m).

NOTE: Data are restricted. Please contact the PI for access.

Related Publications and References:
Hirsh, M.D., 2010, Anammox bacterial diversity in various environments and N removal capacity in the Cape Fear River. University of North Carolina Wilmington, Dept. of Biology and Marine Biology, M.S. thesis, 87 p.

Sampling for the Cape Fear River Estuary (CFRE) was conducted using 20-foot center console boats at University of North Carolina Wilmington (UNCW).

Fifteen stations were demarcated about every two kilometers along the estuarine salinity gradient of the CFRE. Sampling was conducted in April and October of 2009. Sediments were collected using a Petite Ponar® grab from west to east along a cross-estuary transect at each station including, where possible, both banks (depth less than two meters) and both sides of the channel (~12 m). Samples were defined as either east or west bank (EB, WB) (0-2 m water column depth), east or west channel (EC, WC) (8-15 m), as well as east mid-bank (EMB), west bank-shore (WBS) and east bank-shore (EBS) at stations where more than 4 samples were collected. Salinity was measured with a YSI model 650 MDS (YSI Inc., Yellow Springs, OH, USA) in the field at the surface and at the bottom when depths were greater than 1 meter. Sediment samples were treated with 35% H2O2 until all organic matter was dissolved. Samples were then run on a Coulter Counter (model LS-200, Beckman) to measure the distribution of sediment grain sizes. Organic content was measured as a percentage of the ashed weight/pre-ashed weight. Fe (II) and H2S were measured spectrophotometrically from porewater that was fixed with ferrozine and/or diamine immediately after centrifugation the day after they were collected from the CFRE (Stookey, 1960, Cline, 1969). Filtered surface and bottom water was analyzed for NO3- and NH4+ with the standard colorimetric method using a Bran Lubbe continuous flow autoanalyzer.

BCO-DMO Processing Notes:
- Parameter names were modified to conform with BCO-DMO naming conventions.
- Latitude and longitude were converted from degrees and decimal minutes to decimal degrees.
- "N/A" was replaced with "nd" to indicate "no data/not available".
- Blank values were replaced with "nd" to indicate "no data".
- "b/d" was replaced with "below_det" to indicate values below the detection limit.

From NSF Award Abstract:

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).

Estuaries, connecting the freshwater and marine environment, are among the most dynamic and the productive ecosystems on Earth. However, they are under threat from anthropogenic N loading, resulting in various symptoms of eutrophication. The intensity and duration of estuarine eutrophication and the rate of estuarine recovery strongly depend on microbial N removal processes (anaerobic ammonium oxidation (ANAMMOX) and denitrification). Denitrification has been intensively studied in various estuaries, while ANAMMOX as a recently discovered N removal pathway is much less studied in estuarine ecosystems. Existing studies indicate that ANAMMOX rates and its contribution to total N2 production (ANAMMOX significance) are system specific and controlled in part by reaction-scale substrate limitations and by environmental parameters. However, community structure (abundance and composition) of ANAMMOX bacteria have not been linked to their activities along environmental gradients. In addition, ANAMMOX community interactions with aerobic ammonia oxidizers and denitrifyers have not been adequately studied in estuarine and coastal environments.

The investigators will examine the importance of ANAMMOX community structure on their activities along estuarine gradients at the CFRE. In addition, microbial interactions among ANAMMOX, denitrifying and aerobic ammonia oxidizing (AAO) communities will be examined to gain a better understanding of sedimentary N cycles in the estuary. They will address the hypothesis that the total abundance of ANAMMOX bacteria will be linearly correlated to their activities, and that members of ANAMMOX communities are influenced differently by environmental parameters present along the estuarine gradients. Depending on the community structure of ANAMMOX bacteria, temporal and spatial variations of the ANAMMOX rates and its significance to N loss will be observed along the estuary. In addition, they will explore functional linkages among ANAMMOX, denitrifying and AAO communities in estuarine sediments that will alter the pathway of N loss. In order to test the proposed hypotheses, the investigators will conduct interdisciplinary and collaborative research by integrating molecular microbial techniques, 15N isotope tracer methods and multivariate statistic analyses. Thus, this project will address key gaps in our understanding of ANAMMOX ecology by understanding how the community structure of ANAMMOX bacteria influences their activities, and lead to a more complete understanding of estuarine N loss.

The original call for proposals for Emerging Topics in Biogeochemical Cycles (ETBC) was issued in September 2007 by the US NSF Directorate for Geosciences (NSF 07-049).

The Geosciences Directorate (GEO) is substantially augmenting our past funding sources to explicitly support emerging areas of interdisciplinary research. We seek to foster transformational advances in our quantitative or mechanistic understanding of biogeochemical cycles that integrate physical-chemical-biological processes over the range of temporal and/or spatial scales in Earth’s environments. We encourage submission of proposals that address emerging topics in biogeochemical cycles, the water cycle or their coupling, across the interfaces of atmosphere, land, and oceans. Proposals must cross the disciplinary boundaries of two or more divisions in Geosciences (e.g. ATM, EAR, OCE) or of at least one division in Geosciences and a division in another NSF directorate.

Although funding programmatic disciplines continues to provide a robust and adaptable framework to build our understanding of the geosciences and the earth as a system, there are classes of emerging and challenging problems that require integration of concepts and observations across diverse fields. Our goal is to enhance such integration. Successful proposals need to develop intellectual excitement in the participating disciplinary communities. Also encouraged are proposals that have broader educational, diversity, societal, or infrastructure impacts that capitalize on this interdisciplinary opportunity.