The National Estuarine Research Reserve System funds a Graduate Research Fellowship (GRF) program through the 27 National Estuarine Research Reserves. This program provides master's degree students and Ph.D. candidates with an opportunity to conduct research of local and national significance that focuses on enhancing coastal zone management. Fellows conduct their research within a National Estuarine Research Reserve and gain hands-on experience by participating in their host reserve's research and monitoring programs for 15 hours per week. Graduate Research Fellowship projects are based on the reserves' local needs, the reserve system's national priorities and the students' interest. These fellowships provide the student with a stipend of $20,000 per year, and can be funded for up to three years. Each reserve can have a maximum of two GRFs at any one time.

For more information about deadlines and applying,
please visit: http://www.nerrs.noaa.gov/Fellowship/welcome.html

Graduate Research Fellow

Emily Seldomridge
Abstract: Freshwater tidal marshes border tidal streams near the upstream end of the tidal limit, and are likely to undergo significant changes in salinity, tidal inundation, and biogeochemical processes with sea level rise. These tidal marshes fringe many estuarine systems and contain organized networks of channels that convey tidal water deep into marsh systems. The purpose of this study is to examine the geomorphologic, hydrologic, and biogeochemical processes that influence the delivery and processing of nutrient-rich waters into tidal marshes. Objectives of the research are:

1. To make mass balance measurements of nitrate retention for individual marshes.

2. To identify geomorphic and hydrological characteristics of marshes that enhance or limit nitrate retention.

This research is being conducted at the Chesapeake Bay Maryland NERR site located on the Patuxent River near Jug Bay. The research is designed to examine the marsh systems of various sizes at different seasons and tidal stages. These data are then used to develop simple models that can be used with geomorphic and hydraulic data to predict water fluxes and nitrate retention within freshwater tidal systems. Although large marshes retain significant proportions of nitrate within the freshwater tidal ecosystem, their behavior is much more dynamic than smaller marshes. Thus, detail study of a large tidal marsh is examined under varying tidal and seasonal conditions to determine hydraulic, geomorphic, and biologic processes that influence nitrate retention.

The approach of this research is to collect extensive field measurements to calculate water and nitrate flux for tidal marshes. Through a mass balance approach, the amount of nitrate retention is calculated. The results of these mass balance measurements can be compared with in situ and other measurements of denitrification to evaluate the role of denitrification, uptake, and other processes on net nitrate retention. The results of this research will improve our understanding of nitrate processing in freshwater tidal wetlands, and provide simple models to estimate nitrate processing at the ecosystem level.

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Past Graduate Research Fellows

Benjamin M. Fertig
Abstract: Deleterious effects of nitrogen loading from anthropogenic sources in the Chesapeake Bay, such as fertilizer and manure runoff as well as sewage effluents, are well documented. Managing non-point nutrients, particularly nitrogen, in the Chesapeake Bay requires source determination and monitoring. Stable nitrogen isotopes from macroalgae and aquatic plant species have previously indicated spatial patterns of nitrogen sources. Deployments of the eastern oyster (Crassostrea virginica) conducted over the past year in Monie Bay and Maryland Coastal Bays provided promising results, indicating nitrogen sources spatially and temporally.

During this project’s second and third years, I will link the nitrogen sources identified by C. virginica to land uses. The Monie Bay component of the Chesapeake Bay National Estuarine Research Reserve in Maryland is an ideal site for this study because it contains creeks similar in most aspects except for adjacent land use. This allows comparisons between poultry farm runoff (Little Monie Creek), crop agriculture (Monie Creek), and wetlands/forests (Little Creek). Detailed land use datasets of Monie Bay subwatersheds will be collected and ground-truthed for GIS spatial analysis and correlation with 2006 oyster isotope values. These datasets provide a resource to examine linkages with biologically incorporated estuarine nitrogen. Additionally, a STELLA model of oyster isotope physiology and cycling will be developed to predict oyster isotope values at each field station for 2007. This STELLA model will incorporate water quality, land use, and 2006 oyster isotope values and will be validated by deploying oysters in 2007. STELLA models linked with land use data allow generalizations and predictions of nitrogen source to be made for other estuarine systems, including other components of the National Estuarine Research Reserve System. Therefore, I propose to establish the link between land use and oyster tissue nitrogen through spatial analysis, modeling, and fieldwork validation.

Michael Castellano
Abstract. The majority of nutrient pollution in US estuaries is from nonpoint sources. Accordingly, nonpoint pollution research is specifically targeted by the NOAA National Estuarine Research Reserve System (NERR). Recent work coupling hydrology and biogeochemistry has identified the near-open water saturated soil zone as the focal point of nonpoint pollution research; alternating oxic and anoxic conditions at this location can make it function as a conduit or buffer for nutrient pollution. Here, I propose research that will advance our basic understanding of hydrology-nutrient dynamics at the upland-open water interface. I will develop soil texture as a framework for understanding nutrient dynamics and address two overarching questions:

1. What role does soil texture play in nutrient flow and transformation at the terrestrial-aquatic interface?

2. How does a fluctuating water table (driven by precipitation and tide) influence nutrient transport from the unsaturated soil into the groundwater?

Using coupled measures of hydrology and nutrient cycling, I will test the following two hypotheses:

1. Silty soils are better nitrate filters than sandy soils because they stabilize more nitrates in soil organic carbon compounds and remove more nitrates via denitrification.

2. The groundwater table rises higher in silty vs. sandy soils, promoting more nutrient leaching to the groundwater and this process will be exacerbated during high spring tides.

The Chesapeake Bay, MD NERR is located in Harford County- the fastest growing county in the state. Thus, the reserve is particularly concerned with potential increases in nutrient pollution. This proposal offers a broadly applicable framework for understanding nutrient transport and transformation: soil textural gradients. Soil texture provides an attractive approach towards nutrient management because it will enable reserve managers to use existing soil texture maps to predict places and times where open waters are particularly susceptible to upland nutrient pollution and manage accordingly.

The Chesapeake Bay National Estuarine Research Reserve is a living laboratory for CBNERR-MD staff, visiting scientists and graduate students. Since the inception of the nationwide NERR system, a main goal of the program has been to ensure a stable environment for research through long-term protection of reserve system resources. The reserves serve as platforms for long-term research and monitoring, as well as reference sites for comparative studies.