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Marine Moorings
Marine moorings continuously measure data in a single location, providing updated water quality data every 15 minutes. This automated sampling fills in gaps between our offshore monitoring program’s sampling events and provides real-time updates on current conditions. Moorings provide a robust data record that allows scientists to track how water quality parameters are changing over short and long time scales, from hour-by-hour to year-by-year, with minimal effort from field scientists.
King County currently maintains four active moorings in Puget Sound’s Central Basin. In November 2007, we partnered with the Seattle Aquarium to deploy its first automated water quality data collection system in Elliott Bay. Three additional systems are currently deployed: a piling-mounted system at Dockton Park in outer Quartermaster Harbor (Vashon Island), a dock-mounted system at the Yacht Club in inner Quartermaster Harbor, and a buoy-mounted system off Point Williams in Central Puget Sound.
More Information
The goals of this monitoring are to:
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Collect and maintain a long-term dataset of conditions within Puget Sound’s Central Basin.
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Characterize water quality within King County’s marine ecosystem.
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Evaluate spatial and seasonal variation of water quality parameters from year-to-year.
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Determine physical, chemical, and biological dynamics that influence water quality.
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Assess long-term trends in water quality parameters.
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Monitor water quality near King County marine wastewater outfalls.
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Support regional marine monitoring and modeling efforts.
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Evaluate data with regard to Washington State water quality guidelines.
| Sensor | Range | Resolution | Accuracy | Mooring |
|---|---|---|---|---|
| HC-EP Temperature (°C) | -5 to 45 | 0.0001 | ± 0.002 | All |
| HC-EP Conductivity (mS/cm) | 0 to 70 | 0.001 | 0.003 | All |
| HC-EP Salinity (psu) | 0 to 42 | 0.001 | 0.005 psu | All |
| HC-EP Dissolved Oxygen (mg/L) | 0 to 25 | 0.007 | ± 0.1 mg/L or 2%, whichever is greater | All |
| HC-EP Turbidity (NTU) | 0 to 3,000 | 0.06 - 0.17 | ±1% | All |
| Sonde pH (HC-EP) | 0 to 14 | 0.01 | ± 0.1 | All |
| HC-EP Chlorophyll (µg/L) | 0 to 400 | 0.007 -0.037 | ±3% | All |
| pH (SeaFET, recalculated, total scale) | 6.5 to 9.0 | 0.004 | ± 0.02 | Point Williams, Quartermaster Harbor Yacht Club |
| pH initial (not recalculated) | 6.5 to 9.0 | 0.0001 | Requires validation | Point Williams, Quartermaster Harbor Yacht Club |
| Nitrite+Nitrate-Nitrogen (mg/L) | 0.007 to 56 | 0.01 | ± 0.028 or 10% | Point Williams |
| Wind Direction (degrees) | 0 to 360 | 1 | ± 3° | Point Williams, Dockton |
| Vaisala Wind Speed (m/sec) | 0 to 60 | 0.1 | ± 0.3 or ± 3% | Point Williams, Dockton |
| RM Young HD Wind Speed (m/sec) | 0 to 100 | 0.1 | ± 0.3 or ± 1% | Point Williams, Dockton |
| Air Temperature (°F) | -60 to 140 | 0.1 | ± 0.3 | Point Williams, Dockton |
| Pressure (in Hg) | 17.7 to 32.5 | 0.01 | ± 0.015 | Point Williams, Dockton |
| Relative Humidity (%) | 0 to 100 | 0.1 | ± 5% | Point Williams, Dockton |
| Rain Fall (in) | NA | 0.001 | ± 5% | Point Williams, Dockton |
| Photosynthetically Active Radiation (µmol/s/sq meter) | NA | 1 | ± 5% | Point Williams, Dockton |
Obsolete Sensors
| Sensor | Range | Resolution | Accuracy |
|---|---|---|---|
| YSI Depth (m) | 0 to 61 | 0.001 | ± 0.12 |
| YSI Temperature (°C) | -5 to 50 | 0.01 | ± 0.15 |
| YSI Conductivity (mS/cm) | 0 to 100 | 0.001 to 0.1 | ± 0.5% of reading |
| YSI Salinity (psu) | 0 to 42 | 0.01 | 0.1 psu or 1%, whichever is greater |
| YSI Dissolved Oxygen (mg/L) | 0 to 50 | 0.01 | ± 0.1 mg/L or 1%, whichever is greater |
| YSI Turbidity (NTU) | 0 to 1,000 | 0.1 | 0.3 NTU or 2%, whichever is greater |
| YSI Chlorophyll (µg/L) | 0 to 400 | 0.1 | ~0.1 µg/L detection limit |
| Sonde pH (YSI) | 0 to 14 | 0.01 | ± 0.2 |
Download Data
Use our online data visualization tools or download data.
Note: some data may be provisional. Contact MarineWQ@kingcounty.gov for information about the most recent quality control of data.
Documentation
Learn more about our program by reading relevant reports and presentations.
Contact us with any questions or access additional resources in the Science Section Library.