Skagit County sites included in Salish Sea seaweed toxicity study

Oct. 1—The toxicity levels of seaweed at two Skagit County sites were included in a Salish Sea study done by Western Washington University researchers.

The study, published in the scientific journal PLoS One on Sept. 23, looked at three species of edible seaweed at 43 Salish Sea sites, from British Columbia to south Olympia.

The idea for the study originated when Western Washington University researcher Jennifer Hahn was teaching workshops on how to harvest and prepare seaweed for eating straight from the Salish Sea.

Those attending the workshops would ask if boats could cause the seaweed to be unsafe to eat, Hahn said.

"This happened time after time at these workshops," she said.

Hahn said seaweed is a traditional food of many coastal tribes.

When looking into the issue of whether area seaweed is safe to eat, Hahn found no research from the past 30 years and nothing that looked at Canadian and American sites, so she decided to fill the gap.

The 43 sites cover 18 tribal lands, several mussel watch sites and highly industrialized sites.

"We wanted to see the full spectrum, so it's a broad range of sites," Hahn said.

The Fidalgo Bay Aquatic Reserve and Lone Tree Point were the two Skagit County sites tested. Samples were collected during the summer of 2015.

It was found that of the more than 150 chemicals looked at, the majority appeared in levels too low to be of any concern.

The only chemical that worried researchers was polychlorinated biphenyls, which were banned in the U.S. in 1971 after being found to cause cancer.

Polychlorinated biphenyls were a common flame retardant.

The spiral bladder wrack seaweed harvested in Fidalgo Bay was found to have 4.4 micrograms per kilogram of polychlorinated biphenyls, and the bladder wrack seaweed at Lone Tree Point 3.6 micrograms per kilogram.

According to the World Health Organization, the allowable daily intake of polychlorinated biphenyls is 6 micrograms per kilogram per day.

"Even though they're polluted you have to look at what are the benefits and what are the risks," Hahn said. "How might we think about this for our own table?"

Seaweed is high in fiber, antioxidants and micro-nutrients, said Hahn.

Unsurprisingly, the highest contamination was found near sites such as Victoria Harbor in British Columbia and near the Seattle Cruise Terminal.

— Reporter Racquel Muncy: rmuncy@skagitpublishing.com, 360-416-2139, Twitter: @Racquel_SVH

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