Marine Mooring Specifications
Sondes and Sensor Arrays
King County employs YSI 6600 V2 EDS multiparameter sondes for data collection at all of its marine moorings. The YSI 6600 V2 EDS (extended deployment system) sonde consists of a cylindrical, pressure-resistant body with a cable connection at one end and temperature, conductivity (salinity), pressure (depth), dissolved oxygen, turbidity, pH, and fluorescence (chlorophyll) probes on the opposite end. The following table provides specifications for each of the sondes sensors:
YSI 6600 V2 EDS Sensor Specifications
| Sensor |
Range |
Resolution |
Accuracy |
| Temperature (C) |
-5 to 50 |
0.01 |
+/- 0.15 |
| Conductivity (mS/cm) |
0 to 100 |
0.001 to 0.1 |
+/- 0.5% of reading |
| Salinity (PSS) |
0 to 70 |
0.01 |
0.1 |
| Depth (m) |
0 to 61 |
0.001 |
+/- 0.12 |
| Dissolved Oxygen (mg/L) |
0 to 50 |
0.01 |
+/- 0.1 |
| Turbidity (NTU) |
0 to 1,000 |
0.1 |
0.3 |
| pH |
0 to 14 |
0.01 |
+/- 0.2 |
| Chlorophyll (g/L) |
0 to 400 |
0.1 |
Detection Limit – 0.1 |
A meteorological station is included at each mooring location. The “met” stations record air temperature, relative humidity, wind speed and direction, and rainfall.
The sonde/sensor array systems and met stations at each mooring are connected to a YSI 6200 Remote Data Acquisition System (DAS). These DAS are data-logger and telemetry units that manage sensor sampling, data buffering, and cellular telemetry to a base station. Data are collected and uploaded every 15 minutes to the YSI Econet web interface. The web interface allows real-time sampling adjustments, sensor failure detection, calibration evaluation, data acquisition, storage, review, and downloading.
Deployments
The three marine mooring systems that King County currently deploys are located in Elliott Bay at the Seattle Aquarium, in inner Quartermaster Harbor at Dockton Park, and at the entrance to Quartermaster Harbor.
Elliott Bay
The Elliott Bay mooring system is located at, and is a joint project with, The Seattle Aquarium. The mooring system is comprised of two sonde/sensor arrays that are deployed from the Aquarium’s pump house at the end of Pier 59. A weighted-pulley system allows the two sonde/sensor arrays to be deployed at fixed depths – approximately one meter and ten meters below the surface. The meteorological system is located on the roof of the pump house.
Inner Quartermaster Harbor
The inner Quartermaster Harbor mooring system is located in Dockton Park. It’s deployed as a fixed, piling-mounted system on the outermost pier at the Dockton Park marina. As a fixed system, the total water depth, at any given time, fluctuates with the tidal cycle. The single sonde/sensor array is deployed at depths that generally range between 4.5 and 8.5 meters below the surface. The meteorological system is located at the top of one of the pier’s pilings.
Quartermaster Harbor Entrance
The mooring system located at the entrance to Quartermaster Harbor is deployed from an oceanic buoy and consists of two sets of sondes. The anchoring system allows the two sets of sondes to be deployed at consistent depths of 1 meter below the surface and 1 meter above the bottom (approximately -167 feet MLLW). The meteorological system is located on top of the buoy mast.
The buoy system is a Sound Ocean Systems, Inc. (SOSI) offshore buoy body (SOSI ODB-48-1500) equipped with the following:
- Aluminum mast with sensor mounting plates.
- Autonomous mast light and radar reflector.
- Anti-fouling paint and rubber “rub-rails” at two heights.
- Cable fittings.
- Two solar panels.
- Deep-cycle marine battery.
- Voltage regulator.
Along with the YSI 6600 V2 EDS sonde/sensor arrays, which are deployed at both depths, the surface monitoring array includes a SUNA (Submersible Ultraviolet Nitrate Analyzer) sensor, manufactured by Satlantic. The SUNA is a real-time, chemical-free sensor that calculates nitrate calculations based on ultraviolet absorption.
