Seaweed: Superfood or Contaminated Product? Cross-Border Pilot Study on Salish Seaweed Contaminants

• Main Authors: Hahn, Jennifer L, Sofield, Ruth M., Ylitalo, Gina Maria, Poppenga, Robert H., West, James E., Hollenhorst, Steven J., Van Alstyne, Kathy L., Gaydos, Joseph K.
• Format: Text
• Language: English
• Published: Western CEDAR 2016
• Subjects: Keywords: seaweed; Fucus; Nereocystis; contaminants; metals; PAHs; dioxin; indigenous; Salish Sea; recreational harvest; Fresh Water Studies; Life Sciences; Marine Biology; Natural Resources and Conservation; First Nations
• Online Access: https://cedar.wwu.edu/ssec/2016ssec/food_and_food_security/11

Seaweeds are an excellent source of minerals, antioxidants and fiber. While historically consumed by indigenous people, today seaweeds are increasingly being harvested by both indigenous and recreational harvesters. The lack of recent data on contaminants in seaweeds, however, leaves consumers uninformed about potential harmful aspects of eating this otherwise nutritious seafood. To increase our seafood safety knowledge with respect to seaweed, this study compares contaminant concentrations in seaweeds gathered from 21 indigenous food beaches (IFBs) and 20 historically contaminated beaches (HCBs) in the Salish Sea. IFBs are beaches on First Nation reserve lands, on Washington tribal lands, or in traditional territory with minimal history of upland industrial development and where seafood has been harvested or where First Nations/Washington tribes are interested in seaweed harvesting. HCBs include 7 sites that are NOAA Mussel Watch or WDFW Caged Mussel sites--where blue mussels (Mytilus spp.) are used to measure contaminants--with recent documented contamination; 13 additional BC or WA beaches with documented industrial contamination or in proximity to such places. Nereocystis luetkeana and two species of genus Fucus (F. distichus and F. spiralis) were gathered in the spring and summer of 2015 during the common recreational seaweed harvest season. Samples of these commonly consumed brown seaweeds were collected widely throughout the Salish Sea. At each site, collections were made from three separate areas; these collections were then pooled to create a super-composite sample for the site. Currently, 43 samples of F. distichus and F. spiralis are being analyzed for metals; dioxins and furans; polycyclic aromatic hydrocarbons; and persistent organic pollutants. Eighteen super composite samples of N. leutkeana will also be analyzed for metals. We hypothesize that samples collected from IFBs will have lower contaminant levels than those collected from HCBs. Results will be discussed.