Presentation Abstract

The Salish Sea is home to numerous shellfish species which are harvested for commercial, recreational, subsistence, and cultural uses. Shellfish bioaccumulate biotoxins which can cause harm to human health. Paralytic shellfish toxins (PSTs) and Alexandrium spp., the marine phytoplankton that produce them, are regularly present in the Salish Sea, with the earliest written record from 1793. Indigenous people have experienced the effects of PSTs and other biotoxins for millennia. Traditional Indigenous knowledge and practices used to reduce biotoxin exposure include seasonal timing of harvest, observation of wildlife, and shellfish preparation methods. To further reduce the risk of shellfish poisoning, Coast Salish People traditionally prepare butter clams (Saxidomus gigantea) by cutting off the tip of the siphon and cleaning out the stomach of the clam before eating. Scientific literature also indicates that PSTs are more likely to be sequestered in the tip of the siphon for butter clams. In June 2016, butter clams were dug from Birch Bay State Park, WA during a Washington Department of Ecology PST closure of this area, and tested for PSTs using Enzyme-Linked Immunosorbent Assay. The clams were positive for PSTs, and a water sample from nearby Gooseberry Point, Lummi Nation had Alexandrium cells. Some clams were analyzed for PSTs by homogenization of the whole clam, while others were split into siphon tip, stomach contents/gills, foot, neck, and the rest of the clam to identify if removal of the siphon tip and cleaning of the stomach reduces human exposure to PSTs. We will present the distribution of PSTs in toxic butter clams, and compare the whole clams to the clams prepared with traditional cleaning.

Session Title

Harmful Phytoplankton in the Salish Sea: Part I

Keywords

Paralytic shellfish poison, Butter clam

Conference Track

SSE5: Climate Change: Impacts, Adaptation, and Research

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE5-467

Start Date

4-4-2018 2:15 PM

End Date

4-4-2018 2:30 PM

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

text

Language

English

Format

application/pdf

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Apr 4th, 2:15 PM Apr 4th, 2:30 PM

Distribution of paralytic shellfish toxins in whole and partial butter clams and comparison to traditional preparation methods

The Salish Sea is home to numerous shellfish species which are harvested for commercial, recreational, subsistence, and cultural uses. Shellfish bioaccumulate biotoxins which can cause harm to human health. Paralytic shellfish toxins (PSTs) and Alexandrium spp., the marine phytoplankton that produce them, are regularly present in the Salish Sea, with the earliest written record from 1793. Indigenous people have experienced the effects of PSTs and other biotoxins for millennia. Traditional Indigenous knowledge and practices used to reduce biotoxin exposure include seasonal timing of harvest, observation of wildlife, and shellfish preparation methods. To further reduce the risk of shellfish poisoning, Coast Salish People traditionally prepare butter clams (Saxidomus gigantea) by cutting off the tip of the siphon and cleaning out the stomach of the clam before eating. Scientific literature also indicates that PSTs are more likely to be sequestered in the tip of the siphon for butter clams. In June 2016, butter clams were dug from Birch Bay State Park, WA during a Washington Department of Ecology PST closure of this area, and tested for PSTs using Enzyme-Linked Immunosorbent Assay. The clams were positive for PSTs, and a water sample from nearby Gooseberry Point, Lummi Nation had Alexandrium cells. Some clams were analyzed for PSTs by homogenization of the whole clam, while others were split into siphon tip, stomach contents/gills, foot, neck, and the rest of the clam to identify if removal of the siphon tip and cleaning of the stomach reduces human exposure to PSTs. We will present the distribution of PSTs in toxic butter clams, and compare the whole clams to the clams prepared with traditional cleaning.