Tag Archives: Dissolved oxygen problems

Hood Canal avoids a major fish kill following unwelcome conditions

Southern Hood Canal avoided a major fish kill this year, but for a few days in September it looked like conditions were set for low-oxygen waters to rise to the surface, leaving fish in a critical state with no place to go, experts say.

Data from the Hoodsport buoy show the rise of low-oxygen waters to the surface over time (purple color in top two graphs). // Graphic: NANOOS

Seth Book, a biologist with the Skokomish Tribe, has been keeping a close watch on a monitoring buoy at Hoodsport. Dissolved oxygen in deep waters reached a very low concentration near the end of September, raising concerns that if these waters were to rise to the surface they could suddenly lead to a deadly low-oxygen condition. This typically happens when south winds blow the surface waters to the north.

“I started asking around the community to see if anyone had seen evidence of low DO (fish at surface; dead fish; deep fish being observed or found in fishing nets at surface; diver observations) and luckily I had no reports,” Seth wrote to me in an email.

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