Temperature Sensors for Planning Oyster Harvests

Purpose of the Temperature Sensors

To help you plan oyster harvests, you can access water temperature data at NVS Shellfish Growers temperature maps. This data is a tool to help plan your harvests – it doesn't replace the need to take temperatures for each harvest time and location, which is required under the Vibrio control plan rule.

The Department of Health developed this temperature sensor network to assist the shellfish industry in planning oyster harvests. The shellfish industry can monitor temperature trends and make safer harvesting decisions. The temperature sensor data is a partnership with the Northwest Association of Networked Ocean Observing Systems (NANOOS) via their Visualization System (NVS). The NVS Shellfish Growers temperature maps provides near-real-time, map-based data.


The temperature sensor network is comprised of Decagon Em50G data loggers that transmit data via internal cellular/mobile communication. The data loggers have two sensor attachments:

  • ECT Air Temperature Sensor with a radiation shield that measures ambient air temperature.
  • ES-2 Electrical Conductivity Sensor that measures water temperature and electrical conductivity.

Sensor parameters are found in the table below. See more information about Decagon data loggers and sensors.

ECT Air Temperature Sensor

-40 to -20°C: ± 1.0°C

5 to 40°C: ± 0.5°C

40 to 50°C and -20 to 5°C: better than ± 1.0°C
Resolution 0.1°C
Range -40°C to 50°C


ES-2 Electrical Conductivity Sensor
  Temperature Electrical Conductivity

+ 0.01 dS/m or + 10 %

(whichever is greater)

+ 1°C
Resolution 0.001 dS/m 0.1°C
Range 0 to 120 dS/m -40 to 50°C


This project is still in an early implementation phase. We will update this page as additional site locations and capabilities become available.

Site Selection

Deployment locations are prioritized based on the growing area risk category. Growing areas in more stringent risk categories are considered to be a higher need than growing areas in less stringent risk categories. Individual sites were additionally prioritized based on site accessibility and cellular connectivity. Since priority was given to locations near commercial shellfish activity and focus on nearshore harvest, some sites in the network are too shallow at low tide to record water temperature. The data will show no conductivity at times when the water temperature sensor is no longer submerged. Conductivity and water temperature data from unsubmerged waters sensors should be disregarded.

Current Site Locations

  • Burley Lagoon
  • Eld Inlet
  • Hammersley Inlet
  • Henderson Bay
  • Henderson Inlet
  • Hood Canal 1
  • Hood Canal 5
  • Hood Canal 7
  • Hood Canal 8
  • Hood Canal 9
  • Oakland Bay
  • Peale Passage
  • Pickering Passage
  • Port Gamble
  • Samish Bay
  • Skookum Inlet
  • Totten Inlet (North)
  • Totten Inlet (South)


In addition to partnering with NANOOS, we'd like to thank the following partners for hosting data loggers:

  • Calm Cove Shellfish
  • Chelsea Farms
  • Minterbrook Oyster Company
  • Nisqually Tribe Shellfish Farm
  • Port Gamble S'Klallam Tribe
  • Rock Point Oyster Company
  • Sisters Point Shellfish
  • Skokomish Indian Tribe
  • South Sound Mariculture
  • Squaxin Island Tribe
  • Taylor Shellfish Company
  • Wallin's Oysters and Clams
  • Washington State Parks