Marine Water Quality

Puget Sound marine (salt) waters change on a daily, seasonal, and yearly basis. Local weather, freshwater input, climate conditions, ocean circulation, and other factors affect the physical and chemical characteristics of this water. These characteristics, including temperature, dissolved oxygen, nutrients, and ocean acidification, are often defined as “water quality,” and impact the creatures living in this ecosystem. 

Our water quality data provide valuable insight for scientists across the Puget Sound region. It allows us to set baseline (“normal”) conditions so we can understand how conditions are changing over time and how humans may be affecting environmental conditions. We also monitor several locations near King County's wastewater treatment plant outfalls specifically to identify if wastewater discharges are affecting water quality. Some data have been collected for over 50 years, providing remarkable insight into long-term water quality trends in addition to how the environment varies seasonally and from year to year. 

Our sampling covers several beaches in King County as well as multiple locations in Puget Sound’s Central Basin and Whidbey Basin. We conduct sampling from our research vessel, the R/V SoundGuardian, and from moorings that continuously collect data. Sampling methods range from collecting seawater in bottles to deploying advanced sensors to continuously monitor data. 

To learn more about King County’s water quality monitoring program, click on the links below.