Environmental Pollution and Ecotoxicology in North Carolina
U.S. Fish and Wildlife Service / U.S. Geological Survey Cooperative Assessment of Roanoke River Dissolved Oxygen Levels
The Environmental Contaminants program in Raleigh has a 5-year partnership with Roanoke River National Wildlife Refuge and the U.S. Geological Survey's Water Resources Division (USGS) to assess water quality on the Roanoke River. Through an environmental contaminants investigation, five water quality monitoring stations were installed on the river and have collected data that will help the Service interact with State regulators and others on water quality issues important to the refuge.
The project focuses on dissolved oxygen (DO) levels in the lower Roanoke River. Lower Roanoke River and western Albemarle Sound DO levels have been documented below the State's standard for protection of aquatic life. Low DO caused the 1995 fish kill in the Roanoke River including the loss of 9,350 striped bass. Attempts to address DO concerns have been hampered by uncertainty regarding the relative contribution of 1) inputs of oxygen consuming waste from municipal and industrial treatment plants; 2) reservoir discharges; 3) managed flow regimes; and, 4) discharge of waters from riparian wetlands, or backswamps.
The Service identified this data shortfall as a high priority. Consequently, we partnered with the USGS to install and operate continuous monitoring stations on the river. Our aim was to produce high quality data that may be used by managers to determine the relative contribution of the various sources of DO problems and work to address them. Although the relative contribution of the various sources of DO deficits are not known, all sources could be managed to increase instream DO levels. Hence, once their relative affects on the river system are established, management actions will follow.
All five stations have been operational since about April 1, 1998 near Halifax, Oak City, Quitsna, Jamesville and Plymouth. The stations are equipped with a transmission link so that near real-time data (15-minute recordings are transmitted every 4 hours) are available over the worldwide web site maintained by USGS. Data interpretation graphics, raw data, and descriptions of station locations can be viewed by the public at the USGS website, entitled "Roanoke River Water Quality Conditions".
A final report (Bales and Walters 2003) is avaiable on the project. Also, data from the stations have been provided in annual reports of the USGS (Ragland et al. 1999, 2000, 2001, 2002). Provisional data from the most recent 7-day period can be downloaded directly from the website. The availability of the real-time data allows managers to take actions to address declining dissolved oxygen levels and reduce the likelihood of fish kills, while the overall study seeks more permanent solutions.
Publications related to this project:
- Bales, J.D., and Walters, D.A., 2003, Relations among floodplain water levels, instream dissolved-oxygen conditions, and streamflow in the lower Roanoke River, North Carolina, 1997-2001: U.S. Geological Survey Water-Resources Investigations Report 03-4295, 81 p. Available from U.S. Geological Survey at http://pubs.usgs.gov/wri/wri034295/pdf/report.pdf.
- Ragland, B.C., D.G. Smith, R.G. Barker and J.B. Robinson. 1999. Annual Data - Oct. 1, 1997 thru Sept. 30, 1998 Water Resources Data, North Carolina, Water Year 1998, Volume 1. Surface-Water Data. USGS-WDR-NC-98-1, U.S. Geological Survey, Water Resources Division, Raleigh, NC.
- Ragland, B.C., D.A. Walters, G.D. Cartano and J.E. Taylor. 2000. Water Resources Data, North Carolina, Water Year 1999, Volume 1A. Surface-Water Data. U.S. Geological Survey, Water Resources Division, Raleigh, NC.
- Ragland, B.C., D.A. Walters, G.D. Cartano and J.E. Taylor. 2001. Water Resources Data, North Carolina, Water Year 2000, Volume 1A. Surface-Water Data. U.S. Geological Survey, Water Resources Division, Raleigh, NC.
- Ragland, B.C., D.A. Walters, G.D. Cartano and J.E. Taylor. 2002. Water Resources Data, North Carolina, Water Year 2001, Volume 1A. Surface-Water Data. U.S. Geological Survey, Water Resources Division, Raleigh, NC.
Tom Augspurger, Ecologist, 919-856-4520 ext. 21
Sara Ward, Ecologist, 919-856-4520 ext. 30