An Early Warning Success Story

On June 1, 2026, low levels of Paralytic Shellfish Poisoning (PSP) toxins began to show up in southern Hood Canal shellfish, an area of Puget Sound that had been impacted by PSP only once before. The following week, SoundToxins monitors reported low levels of Alexandrium cells, causing shellfish managers to increase surveillance testing. As shellfish PSP results were finalized, and SoundToxins monitors raced to report their cell counts, precautionary closures were put in place. SoundToxins provided early warning that PSP producing cells were present and spreading, which allowed shellfish managers to assess risk, support precautionary closures, and voluntary shellfish holds. The swift actions of SoundToxins, which is supported by IOOS NHABON through NANOOS, and other partners resulted in no reports of PSP illness from shellfish consumption during the most toxic event in Hood Canal history.

Photo Credit: WA Dept. of Health

8 Sep 2026