Continuous Water-Quality Monitoring at Lake Mattamuskeet, North Carolina

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The U.S. Fish and Wildlife Service (USFWS) has partnered with the U.S. Geological Survey to establish two automated water quality monitoring stations and one precipitation monitoring station at Lake Mattamuskeet. Lake Mattamuskeet comprises 41,084 acres of the 50,180 acre Mattamuskeet National Wildlife Refuge (NWR) and is divided by a causeway. The causeway effectively splits the lake into two distinct basins. The west side's submerged aquatic vegetation, bird use, and fisheries have declined. The fishing public and fisheries agencies have been concerned with water level and salinity management.

Monitoring

Map of monitoring stations on Lake Mattamuskeet
Map of monitoring stations on Lake Mattamuskeet(Public domain.)

A primary objective of the refuge is long-term monitoring of key limnological variables to inform lake management decisions. Other objectives include integration of national and regional inventory and monitoring goals, leveraging within-USFWS and external partnerships, building on proven approaches for limnological assessments, generating high quality data, and facilitating resolution of water-quality concerns. Understanding and resolving these problems will be directly facilitated by the monitoring data from this project. Monitoring stations measure dissolved oxygen, temperature, pH, conductivity, salinity, water level, wind direction, turbidity, and light (Table 1). The stations provide data to inform management and assist cooperative assessments of the lake and its living resources.

Monitored Water-quality Parameters
Physical Data                     Chemical Data             Biological Data
Dissolved oxygen           Total phosphorous      Chlorophyll a
Water temperature         Total nitrogen             Phytoplankton
pH                                   Ammonia                    Algal toxins
Conductivity                   Kjeldahl nitorgen        
Salinity                           Total organic N            
Water level                     Nitrate + nitrite
Wind direction               Total inorganic N
Turbidity                        
Light attenuation
Secchi depth
Total solids
Suspended solids
Table 1: Inventory and Monitoring project parameters are in bold, all other parameters funded through various partnerships.

Results of the first year monitoring (September 2012 through September 2013) are available in the 2013 Water-Data Report:

Second year results (September 2013 through September 2014) are in review and compilation for presentation through similar on-line "Water-Year Summary" pages for each station.

The NC Wildlife Resources Commission (NC WRC) is a key partner at Lake Mattamuskeet. In FY14, NC WRC funded operations as well as installation of staff plates at four lake outfall canals which were surveyed to NAVD88 datum elevations by global navigation satellite system. This optimizes utility of the water level measurements made at the continuous monitoring stations in the main lake -- a significant project enhancement. NCWRC's ongoing support of operations in 2016 is appreciated.

The important partnership with the Ambient Lakes Monitoring Program of the NC Division of Water Resources (NC DWR) (described in detail in the FY13 project update) continued through 2016. At no additional costs to the USFWS, grab samples are collected by USGS and analyzed by the NC DWR Water Sciences Chemistry Laboratory. The NC DWR benefits through obtaining data they can use in their Ambient Lakes Monitoring Program and the NC Trophic State Index. The USFWS benefits by gaining data on additional water quality parameters to improve understanding of lake health. All data from this partnership are housed in the NC Lakes Database maintained by NC DWR and available to the public via STORET.

In 2014, the USGS coordinated another partnership by getting Lake Mattamuskeet samples included in the Auburn University / USGS project: Forecasting toxic cyanobacterial blooms throughout the southeastern U.S.

Two data summaries were delivered to managers and stakeholders in FY14:

  • Augspurger T. 2014. 
    Historic water quality data for Lake Mattamuskeet and initial retrospective analyses. 
    Lake Mattamuskeet Technical Working Group Meeting. 
    August 26, Swan Quarter, NC.
  • Moorman M. 2013. 
    USGS continuous water-quality monitoring at Lake Mattamuskeet National Wildlife Refuge. 
    November 18, Swan Quarter, NC.

Long-term monitoring of lake water quality and quantity is critically important to informing lake management decisions, and the data from this project are already being utilized. The utility of the project was emphasized by inclusion of the monitoring stations for long-term funding among the action items (1.g) for the newly formed Mattamuskeet Collaboration Team.

Data Methods

Hydrologist servicing a station
Hydrologist servicing a station on Lake Mattamuskeet(Public domain.)

Station operation follows established protocols (Wagner et al. 2006. Guidelines and standard procedures for continuous water-quality monitors -Station operation, record computation, and data reporting: U.S. Geological Survey Techniques and Methods 1-D3.).

The monitors consist of:

  • a metal housing with a data collection platform
  • satellite transmitter
  • cables with waterproof connectors
  • water quality sensors
  • batteries
  • solar panels
  • staff gage

Field meters are used to standardize and adjust the station probes and document their precision and accuracy. Stations are serviced regularly to ensure data quality.

Data Management

Lake conditions are available near real-time via the USGS's National Water Information System website. The stations make measurements every 15-minutes, and data are transmitted to the GOES satellite and uploaded to the website every hour. Data can be viewed by the public, refuge management, and cooperators at these sites:

Following quality control / quality assurance reviews, data is permanently archived in the USGS's National Water Information System Database and in an annual Water-Data Report.