• System-wide Monitoring Program
  •   Phase 1 (Abiotic)
    • Water Quality
      • Site Selection
      • Hydrographic
      • Nutrients
    • Meteorological
      • Introduction
      • Site Selection
      • Methods
    •   Real Time data
      • CDMO
      • YSI
  •   Phase 2 (Biodiversity)
  •   Phase 3 (Land Use)
  • Fact Sheets
•   Current Projects
  • Ecology of Salt Panne Habitats
  • Winter Ecology of Marshbirds
  • Winter Ecology of Shorebirds
  • Diamondback Terrapin Population Surveys
  • ECSC Partnership
• Past Projects
• Graduate Research Fellowships

Phase 1 (Abiotic)

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Water Quality

Hydrographic

One data logger is deployed at each permanent monitoring station in the Grand Bay estuary at all times. Two permanently assigned data loggers are interchanged among each site. Sites are accessed using a small skiff equipped with an outboard motor. During transport, each sonde is wrapped in a white towel soaked in tap water and placed horizontally in a cooler for insulation against jarring. For deployment, the data loggers are affixed to a PVC rack using a stainless steel hose clamp, as well as, hung by the pail from a PVC hook built into the rack for additional support. This rack is lowered into a five inch diameter stainless steel (SS) pipe that has been bolted to a log piling driven into the mud at each site. The SS pipes have cut outs to ensure adequate tidal flushing and exposure of the probes to ambient water conditions. A grate across the bottom of the pipe prevents the rack from descending beyond the bottom of the pipe and ensures that the logger monitors at the same depth on every deployment. The pipes, along with the probes, are also coated with an anti-fouling paint to minimize biofouling.

As a quality assurance measure, a discreet reading is taken with a freshly calibrated sonde and recorded on the calibration sheet during sonde deployment and retrieval. During retrieval, the data loggers are again wrapped in a saturated white towel and placed in a cooler for transport to the lab. At least two data points are recorded while the sonde is wrapped in the towel to record post-deployment dissolved oxygen in 100% water-saturated air. The other post-deployment calibrations are performed in the laboratory prior to cleaning to determine if instrument drift has occurred and to evaluate the validity of the data. After post-deployment calibrations, the sondes are cleaned and stored in calibration cups until the next deployment.

Sonde cleaning and calibrations of the DO, Conductivity, Depth, pH, and Turbidity probes are performed as outlined in the YSI 6600 Extended Deployment Sonde Manual. For Conductivity and Salinity, YSI calibrator solution 3169 (50,000 µS/cm) is used without dilution. For pH calibrations, YSI calibrator solution 3822 and 3823 are used for pH 7 and 10, respectively. A two-point calibration is used for Turbidity, distilled water serves as the calibrator solution for 0 NTU and YSI 6073G is used for 123 NTU. Depth is calibrated in air and is barometrically corrected. The DO membrane is replaced and calibrated every deployment. It is allowed to stretch for 16-20 hours, and re-calibrated prior to actual deployment. The sonde is programmed to brush the probes 1 minute prior to the actual measurement. All data are recorded in Central Standard Time.