Legacy and emerging contaminants in seaweeds of interest for Washington state aquaculture development

PRINCIPAL INVESTIGATOR: Ruth Sofield (Western Washington University)

CO-INVESTIGATORS: Kathryn Van Alstyne (Western Washington University)

Seaweed is a traditional food in many Pacific Northwest Indigenous Asian and Pacific Islander communities, and a general interest in harvesting, farming and consuming seaweed is growing. However, seaweeds have been shown to accumulate contaminants at elevated levels that can be harmful to human health. Marine farmers and harvesters in Washington need access to information regarding the contaminants present in Salish Sea seaweeds and how these contaminants vary among species and over time.

Washington Sea Grant-funded researchers are building from previous work to conduct a more comprehensive assessment of seaweed contamination in Washington. The team is analyzing how concentrations of contaminants of concern vary seasonally and inter-annually, spatially and among seaweed species. They are also investigating the potential for passive water samplers to predict the amounts of contaminants that will accumulate in farmed kelps. The team is also collaborating with the Swinomish Tribe and K–12 teachers to develop lesson plans about seaweed.