Spatially-nested monitoring of Puget Sound: Characterizing surface water quality over multiple scales

Marine waters of Puget Sound and the greater Salish Sea are an important natural resource for people living in Washington State. Changes in water quality occur in response to both evolving ocean conditions and regional alternations of the environment by humans. To protect Washington's marine waters Ecology must quickly and accurately inform the public and stakeholders about present water quality conditions. Reporting on the frequency, duration, and scale of processes that affect marine water quality is important to us.

Conventional monitoring programs often collect high-resolution data in a single dimension, i.e., X/Y, time, or depth. Due to the ephemeral nature, immense scale, and complexity of estuarine processes interpreting these data can be challenging without additional contextual information.

To develop products over larger space and time scales Ecology deployed a Turner Designs C3 fluorometer in a water intake onboard the Victoria Clipper, a passenger ferry traveling daily between Seattle, Washington and Victoria, British Columbia. The sensor provides measurements of:

  • Chlorophyll fluorescence (to monitor algae abundance)
  • Turbidity (to monitor water clarity)
  • Temperature (to monitor water circulation and habitat conditions)
  • Colored Dissolved Organic Matter (CDOM) fluorescence (to monitor river and stormwater discharge)
  • Ferry data are used to daily calibrate ocean color satellite images which provides estimates of chlorophyll, CDOM, and suspended sediment concentrations, and other indices of algae abundance.

    These products provide a cost-effective way to extend the monitoring capabilities and improve our ability to characterize, understand, and predict marine water quality throughout Puget Sound.