Grantee Research Project Results
1999 Progress Report: CISNet: Nutrient Inputs as a Stressor and Net Nutrient Flux as an Indicator of Stress Response in Delaware's Inland Bays Ecosystem
EPA Grant Number: R826945Title: CISNet: Nutrient Inputs as a Stressor and Net Nutrient Flux as an Indicator of Stress Response in Delaware's Inland Bays Ecosystem
Investigators: Ullman, William J. , Krantz, David E. , McKenna, Thomas E. , Madsen, John M. , Scudlark, Joseph R. , Andres, A. Scott , Wong, Kuo-Chuin
Institution: University of Delaware
Current Institution: University of Delaware , University of Toledo
EPA Project Officer: Packard, Benjamin H
Project Period: October 1, 1998 through September 30, 2001 (Extended to September 30, 2002)
Project Period Covered by this Report: October 1, 1998 through September 30, 1999
Project Amount: $600,000
RFA: Ecological Effects of Environmental Stressors Using Coastal Intensive Sites (1998) RFA Text | Recipients Lists
Research Category: Environmental Statistics , Aquatic Ecosystems , Ecological Indicators/Assessment/Restoration
Objective:
The objectives of the Delaware CISNet program are to document the sources and sinks of nutrients (N and P) and organic carbon in Delaware's Inland Bays Watershed. Rehoboth and Indian River Bays, two components of this ecosystem, are representative of a common, but understudied class of estuarine and estuarine lagoonal ecosystems along the East and Gulf coasts of the United States. Both Rehoboth and Indian River Bays receive excessive nutrient and carbon fluxes from agricultural, municipal, domestic, and industrial sources. The specific objectives of this study are to: (1) determine the sources, magnitudes, and spatial and temporal variability of nutrient (N and P) fluxes, the primary stressors in this system, to Rehoboth and Indian River Bays; (2) assess the magnitude of nutrient sinks in this system; and (3) develop conceptual and simple quantitative models that relate these inputs and outputs to more easily measured and monitored forcing parameters, such as precipitation, temperature, season, groundwater levels, and surface water discharge.
This study will determine the gross fluxes of nutrients into and out of the Inland Bays system and the net annual and seasonal fluxes to the Bays as indicators of the impact of the nutrient-flux stressor.
Progress Summary:
The research consists of six component projects. Progress toward the overall objectives has been made as follows:
Inputs From Surface Waters. Baseflow sampling was initiated in late October 1999, and continues on an approximately bimonthly schedule. A total of 13 tributary streams, representing watersheds with a wide range of land use and land cover, were sampled 21 times during the reporting period. The following parameters were measured in the field: pH, conductivity, and dissolved oxygen. Samples also were collected for the determination of the following parameters in the laboratory: dissolved organic and inorganic phosphorus, dissolved inorganic and organic nitrogen, dissolved silicate, dissolved organic carbon, particulate phosphorus, nitrogen, organic carbon, chlorophyll-a, and filterable solids. Stormwater discharges also were sampled on four occasions during the reporting period.
Atmospheric Deposition. Monitoring of precipitation chemistry is conducted on a continual, ongoing basis at a site in Cape Henlopen State Park, under the auspices of the NOAA-AIRMoN Program. Additional sampling was conducted on Indian River Bay from June?November of 1999, under support from the EPA-National Estuaries Program. Substantial differences were found between the results at these two stations, indicating that local sources of nitrogen play an important role in the total atmospheric flux of N. A recent analysis indicates that the atmospheric wet and dry deposition of nitrogen (nitrate + ammonium + organic N) provides between 14 percent (Indian River Bay ) and 24 percent (Rehoboth Bay) of the total annual N input.
Groundwater Studies. Thermal infrared imagery was collected during April 1999, to identify sites of significant groundwater seepage in the Inland Bays. The preliminary analysis of this imagery indicates that the temperature resolution of ?0.2o C is sufficient to identify seepage on the basis of thermal anomalies. Reconnaissance for the identification of field sites for the direct determination of groundwater fluxes continues.
Exchange of Water at Marine Boundaries. Initial results of current surveys at Indian River Inlet (the principal direct connection to the coastal ocean), Massey's Ditch (the connections between Indian River and Rehoboth Bays), and in the Lewes-Rehoboth Canal (the connections between Rehoboth and Delaware Bays) have been completed. Analysis of these data is in progress. Some of this data was collected during Hurricane Floyd, and should provide some interesting information concerning the impact of severe storms on flushing and nutrient fluxes.
Nutrient Chemistry of Bay Waters. Surface samples from 40 to 45 stations were collected eight times from March to November of 1999. At each station, a suite of parameters similar to those determined at tributary sites was determined and similar samples were collected for laboratory analysis. The analysis of these samples is still in progress.
Sediment Storage of Nutrients. No progress has been made in this area. This work is scheduled for FY 2001. We have initiated collaboration with other agencies interested in this work. Additional funding from the Delaware Department of Natural Resources and Environmental Control, the Delaware Sea Grant College Program, the Center for the Inland Bays, the Delaware Geological Survey, the US EPA/National Estuary Program, and the U.S. Geological Survey have allowed us to more rapidly collect some of the data required for this study and, in some cases, expand this study in both extent and depth. In addition, we have established a data management system to maintain our water quality data. This system is still being improved, but will ultimately allow easy access by State of Delaware managers and other collaborators to the results of our monitoring efforts.
Future Activities:
Inputs From Surface Waters. Base flow and storm discharge sampling continues. Analytical work continues. Initial analysis of the first year data is beginning.
Atmospheric Deposition. Additional studies of the spatial variability of atmospheric N concentrations and fluxes are planned. A particular focus will be on the ammonia gas concentrations, as these may reflect specific agricultural practices in the watershed.
Groundwater Studies. Analysis of thermal imagery continues. Seismic and ground-penetrating radar studies will start in the spring of 2000, possibly with the addition of a resistivity survey to map subsurface salinities. Initial direct field measurements of groundwater discharge also will begin in the spring of 2000.
Exchange of Water at Marine Boundaries. Analysis of initial data continues. A redeployment of current meters at Indian River Inlet is planned for spring 2000.
Nutrient Chemistry of Bay Waters. Analytical work continues. Initial analysis of the first year of data and comparison with historical data sets is planned for spring/summer of 2000. A second year of data will be needed because of the unusual weather conditions encountered in Year 1.
Sediment Storage of Nutrients. This work will begin in late fall of 2000.
Journal Articles:
No journal articles submitted with this report: View all 92 publications for this projectSupplemental Keywords:
hydrology, geology, Mid-Atlantic, marine, precipitation, meteorology., RFA, Scientific Discipline, Geographic Area, Water, Ecosystem Protection/Environmental Exposure & Risk, Hydrology, Nutrients, Ecology, Water & Watershed, Ecosystem/Assessment/Indicators, Ecosystem Protection, Chemistry, State, Monitoring/Modeling, Ecological Effects - Environmental Exposure & Risk, Air Deposition, Mid-Atlantic, Watersheds, bays, ecological exposure, aquatic ecosystem, environmental monitoring, fate and transport, coastal ecosystem, nutrient transport, stressors, meteorology, Delaware (DE), nutrient flux, coastal zone, public information, chemical speciation, CISNet Program, public reporting, Indian River Bay, soil, aquatic ecosystems, ecosystem, ecosystem health, water quality, nutrient cycling, stress responses, nutrients as stressors, Rehoboth Bay, nutrient transport model, atmospheric deposition, atmospheric chemistry, groundwaterRelevant Websites:
http://www.udel.edu/dgs/ftp/cisnet/CHEMDATA/
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.