2001 Progress Report: CISNet for the Neuse River Estuary, NC: A Program for Evaluating Nitrogen Driven Eutrophication Associated with Changing Land Use in a Coastal Watershed

EPA Grant Number: R826938
Title: CISNet for the Neuse River Estuary, NC: A Program for Evaluating Nitrogen Driven Eutrophication Associated with Changing Land Use in a Coastal Watershed
Investigators: Luettich Jr., Richard A. , Paerl, Hans , Pinckney, Jay
Institution: University of North Carolina at Chapel Hill
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1998 through September 30, 2001
Project Period Covered by this Report: October 1, 2000 through September 30, 2001
Project Amount: $555,300
RFA: Ecological Effects of Environmental Stressors Using Coastal Intensive Sites (1998) RFA Text |  Recipients Lists
Research Category: Environmental Statistics , Water Quality , Ecosystems , Ecological Indicators/Assessment/Restoration

Objective:

The overall objective of the UNC-CH CISNet project is to build on the historical water quality data set in the Neuse River Estuary (NRE), and to enhance and expand the ongoing monitoring and process-based research being conducted there. Major components of this research include: (1) monitoring of water quality, (2) continuous monitoring of circulation, and (3) data management, archival, and integration.

Progress Summary:

Monitoring of Water Quality Parameters Along the Length of the NRE

The water quality monitoring program initiated in 1994 has been continued through this reporting period. We (IMS) visited 19 mid-estuary stations along the NRE at biweekly intervals. Water column profiles of temperature, salinity, irradiance, pH, and dissolved oxygen were determined at each station. Water samples were collected at 11 mid-channel stations between Streets Ferry Bridge (SFB) and Pamlico Sound (PS), the South River station (component 3), and two near-shore sampling stations. Dissolved nutrients (nitrate, nitrite, ammonium, silicate, orthophosphate), particulate carbon and nitrogen, photopigments, and primary productivity were measured in near surface and near bottom samples.

We have processed, analyzed, and distributed the biweekly hydrographic data since the inception of this project (http://www.marine.unc.edu/neuse/modmon). Additionally, we have assessed the concentrations of nutrients and chlorophyll a through August 2001. In the 8 year context (dating back to 1994), 2001 was a low discharge year with low dissolved inorganic N loading. Owing to the low discharge, salinities in the NRE were relatively high. Occurrences of low dissolved oxygen were comparable to previous years and perhaps most closely resembled the low discharge year of 1997. The low discharge and consequently low flushing rates allowed NOx concentrations to drop substantially (due to extended time for biological uptake) as water traveled over the 20 km stretch immediately downstream from Streets Ferry Bridge. Chlorophyll a levels were less in 2001 than in 2000. In general, the longitudinal positions of maximum chlorophyll a concentrations seem to correspond roughly to the 200 mg/L NOx concentration in the estuary.

Continuous Monitoring of Circulation and Flushing of the NRE

Data collected during the 1999-2000 field seasons of this project clearly show the process of wind driven upwelling across the upper portion of the NRE (upstream of the bend at Cherry Point). Winds blowing toward the north cause downwelling of oxygenated surface water near the north shore and upwelling of low oxygen bottom water near the south shore. Southward directed winds cause the opposite effect. This upwelling brings low oxygen water up into the water column and hence into potential contact with pelagic fish that would otherwise avoid such waters. We believe that this is a causal mechanism for fishkills that frequently occur in this section of the NRE.

Systematic Management, Archival, and Integration of Data From All Ongoing NRE Research

All mid-estuary water quality data are stored in spreadsheets (Microsoft Excel) that are available for other NRE researchers. The data sets also include water quality information gathered by our companion groups at the North Carolina Department of Water Quality (NCDWQ) and Weyerhauser, Inc. The integration of IMS data with NCDWQ and Weyerhauser provides a weekly snapshot of water quality in the NRE. Data from 1994-2001 are available electronically and on compact disc (CD) from IMS, and graphical summaries of the hydrographic data can be accessed at the Web site.

The integrated water quality data set has become the backbone of water quality modeling efforts in support of the State of North Carolina's effort to set a total maximum daily load (TMDL) on nitrogen for the NRE. Three coordinated but independent studies reached consistent conclusions about the nitrogen loading reduction required for the NRE to meet established chlorophyll a based water quality standards. These results were used to set a draft TMDL for nitrogen during 2001.

Future Activities:

We will continue the water quality monitoring programs described above. Our laboratory will continue to analyze samples, and the data will be processed, stored, and distributed as we have done in the past. Furthermore, we are continuing with data analyses to look for relationships among driving factors (e.g., freshwater discharge) and patterns in water column hydrography, nutrients, and oxygen concentrations.


Journal Articles on this Report : 4 Displayed | Download in RIS Format

Other project views: All 82 publications 21 publications in selected types All 19 journal articles
Type Citation Project Document Sources
Journal Article Borsuk ME, Stow CA, Luettich Jr. RA, Paerl HW, Pinckney JL. Modelling oxygen dynamics in an intermittently stratified estuary: estimation of process rates using field data. Estuarine, Coastal and Shelf Science 2001;52(1):33-49. R826938 (2001)
R826938 (Final)
R825243 (1999)
R825243 (Final)
R827957 (Final)
  • Full-text: ScienceDirect-Full Text HTML
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  • Abstract: ScienceDirect-Abstract
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  • Other: ScienceDirect-Full Text PDF
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  • Journal Article Luettich RA, Carr SD, Reynolds-Fleming JV, Fulcher CW, McNinch JE. Semi-diurnal seiching in a shallow, micro-tidal lagoonal estuary. Continental Shelf Research 2002;22(11-13):1669-1681. R826938 (2000)
    R826938 (2001)
    R826938 (Final)
    R828677C001 (2002)
    R828677C001 (2003)
    not available
    Journal Article Paerl HW, Bales JD, Ausley LW, Buzzelli CP, Crowder LB, Eby LA, Fear JM, Go M, Peierls BL, Richardson TL and Ramus JS. Ecosystem impacts of three sequential hurricanes (Dennis, Floyd and Irene) on the US's largest lagoonal estuary, Pamlico Sound, NC. Proceedings of the National Academy of Sciences USA 2001;98(10):5655-5660. R826938 (2001)
    R826938 (Final)
  • Full-text from PubMed
  • Abstract from PubMed
  • Associated PubMed link
  • Journal Article Paerl HW, Dennis RL, Whitall DR. Atmospheric deposition of nitrogen: implications for nutrient over-enrichment of coastal waters. Estuaries and Coasts 2002;25(4):677-693. R826938 (2001)
    R826938 (Final)
    R828677C001 (Final)
  • Abstract: SpringerLink
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  • Other: Prepublication paper
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  • Supplemental Keywords:

    watersheds, estuary, precipitation, nitrogen, ecosystem, aquatic, ecology, monitoring, Atlantic coast, North Carolina, NC., RFA, Scientific Discipline, Geographic Area, Water, Ecosystem Protection/Environmental Exposure & Risk, Nutrients, Ecology, Water & Watershed, Ecosystem/Assessment/Indicators, Ecosystem Protection, Chemistry, State, Monitoring/Modeling, Ecological Effects - Environmental Exposure & Risk, Air Deposition, Southeast, Biology, Watersheds, environmental monitoring, risk assessment, coastal ecosystem, eutrophication, aquatic ecosystem, hydrological stability, ecological exposure, coastal watershed, estuaries, fish kills, meteorology, bioavailability, coastal zone, algal growth, coastal environments, CISNet Program, hypoxia, esturarine eutrophication, estuarine ecosystems, algal blooms, anoxia/hypoxia, aquatic ecosystems, water quality, North Carolina (NC), Neuse River Estuary, stress responses, atmospheric deposition, ecological response, land use, nitrogen

    Relevant Websites:

    http://www.marine.unc.edu/ Exit

    Progress and Final Reports:

    Original Abstract
  • 1999 Progress Report
  • 2000 Progress Report
  • Final Report