Research Elucidates the Origins of Puget Sound Hypoxia
Researchers at Battelle Marine Science Laboratories, sponsored through the National Centers for Coastal Ocean Science’s Coastal Hypoxia Research Program, have found that hypoxia was more common in Puget Sound before and after Euroamerican settlement than during most of the 20th century, indicating non-anthropogenic origins. Elucidating the origins of Puget Sound hypoxia is critical for developing effective strategies for managing hypoxic events.
Using paleoecology techniques with deep-water sediment cores, this study revealed that historic hypoxia resulted from an influx of marine-borne organic matter, as opposed to land-based nutrient inputs common in other coastal systems, and conditions conducive to hypoxia may be returning. The frequency of hypoxic conditions in Puget Sound has increased recently, affecting both recreationally and commercially important marine species, and has received increasing public attention as a result of recent fish kills.
To address this, future research will focus on determining whether current hypoxic events are the result of anthropogenic land-use changes, part of a naturally occurring cycle or a combination of factors.