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Date Permissions Signed
Date of Award
Department or Program Affiliation
Master of Science (MS)
McPhee-Shaw, Erika E.
Moore, Stephanie K.
Bodenstein, Leo R., 1957-
Since the 1950s, the Washington State Department of Health has routinely monitored the suite of toxins in shellfish associated with Paralytic Shellfish Poisoning. These toxins, known collectively as Paralytic Shellfish Toxins, are produced by species of the marine dinoflagellate in the genus Alexandrium. The role of the monitoring program is primarily to protect public health and safety; and therefore, use of these data for long-term statistical analysis has been limited due to opportunistic and irregular sampling of various shellfish species in space and time. However, some studies suggest that initiation of these toxic events have recently shifted to earlier in the year (Hanein and Borchert, 2015). To test this hypothesis, I extracted a subset of these data to analyze for trends in timing of bloom initiation and location of Paralytic Shellfish Toxins after the first annual appearance. I did not find that bloom initiation to be occurring earlier in the year in any subbasins or regulatory closure zones which may indicate that a shift is either absent or undetectable. This contrasts with the finding of others that Paralytic Shellfish Toxins are being detected earlier in the year and indicate that endogenous conditions are a stronger driving factor in bloom initiation than larger climatic shifts. Additionally, although PST has been observed to be more widespread in recent years, I observed no clear progression of shellfish toxicity from one basin to another within any particular year. There was also no clear spatial relationship between the locations of cyst beds (i.e., areas with high concentrations of dormant cysts in sediments) and locations where PST is first detected in shellfish.
Alexandrium, Paralytic Shellfish Poison, Paralytic Shellfish Toxin, Puget Sound, Salish Sea
Western Washington University
Subjects – Names (LCNAF)
Washington (State). Department of Health.
Subject – LCSH
Algal blooms--Monitoring--Washington (State)--Puget Sound; Paralytic shellfish poisoning--Washington (State)--Puget Sound; Poisonous shellfish--Washington (State)--Puget Sound
Puget Sound (Wash.)
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Taylor, Margaret, "Spatial and temporal trends of the annual first detections of Paralytic Shellfish Toxin in Puget Sound, WA" (2020). WWU Graduate School Collection. 989.