Hood Canal Dissolved Oxygen Program

When viewing the serene waters of Hood Canal, there is a temptation to perceive the Hood Canal watershed as a healthy and stable ecosystem.  The calm surfaces however, are not indicative of the complex processes taking place below the surface.  Local newspaper chronicles, a published national report, and legislative focus have documented the occurrence of low dissolved oxygen (DO) levels which have affected marine life on Hood Canal and resulted in an emergency fisheries closure.

Our organization, in conjunction with 30+ additional stakeholders, have designed and implemented a science-based corrective action program (Hood Canal Dissolved Oxygen Program or HCDOP) in an effort to better understand the biogeochemical dynamics of Hood Canal and develop methods and means to mitigate the problem.

Current and historical data have indicated that alterations of chemical processes in Hood Canal have occurred over multiple generations to cumulatively result in the current state of concern.  March 2005 marked the beginning stages of the 3-year HCDOP.  See www.hoodcanal.washington.edu for more information.

Our organization is directly contributing to the freshwater and marine water sampling tasks of the HCDOP.  During the summer of 2003, the staff had the opportunity to spend time on a University of Washington research vessel, Thomas G. Thompson.  The goal of the voyage was to train staff in the collection of water samples at established locations in Puget Sound and Hood Canal.  The analysis included testing for dissolved oxygen, chlorophyll, and nutrients.

Since August 2003, our organization has coordinated a weekly sampling effort in the marine waters of Hood Canal with the contribution of trained volunteers.  This sampling effort has resulted in a significant increase in the understanding of marine water-quality dynamics affecting the watershed. WDFW has also used the weekly sampling data to aid in assessing the status of Hood Canal fisheries.

Understanding the causes and processes resulting in low dissolved oxygen events in Hood Canal will require detailed hydrodynamic and other models.  These models are being developed by the University of Washington.  The sampling efforts within the HCDOP will provide actual measured parameters for running the models.  Variations in the atmosphere, climate, and ocean inputs may also be evaluated.  Upon verification of the models, variations in specific nutrient loadings, freshwater inflow and additional factors can be studied to develop potential corrective actions and the continuing impact such efforts may have on dissolved oxygen levels.

Our organization supports the research and sampling with an expectation of finding conclusive explanations regarding the complex processes resulting in low dissolved oxygen and its subsequent impact on the Hood Canal watershed.