Haines PSP levels second highest in region
August 22, 2019
Levels of paralytic Shellfish Poisoning (PSP), a potentially-fatal illness caused by eating shellfish contaminated by natural toxins, are on the rise in Southeast Alaska.
This summer, Haines came in second only to Juneau in PSP toxicity levels tested in nine Panhandle communities. All nine areas significantly exceeded the threshold of safely consumable limits set by the U.S. Food and Drug Administration (FDA).
Alaska health officials in July reported the first case of PSP poisoning in a patient on the Alaska Peninsula. The patient ate a clam harvested on the beach, but survived after treatment.
In June, levels in Haines mussels tested at 3,594 micrograms per 100 grams—nearly 45 times the FDA’s limit— “which means three or four mussels would certainly hospitalize a big guy,” said Bruce Wright, a scientist whose studied the algae that infects shellfish in Alaska since the 70s.
PSP is caused when a single-cell marine plant, a phytoplankton called Alexandrium, produces toxins in an algae bloom, commonly called a red tide. Toxins are carried throughout the ecosystem with the tides, and ingested by filter-feeding shellfish, which accumulate the toxins inside their tissue, Wright said.
Warming waters will make for an earlier and longer season for the Alexandrium to bloom, Wright said.
University of Alaska Southeast researcher John Harley said that, like any plant, the algae favors certain conditions to bloom. “Particular species of phytoplankton tend to proliferate more when the water temperatures are above 8 and 10 degrees Celsius,” he said. “Winter ocean temperatures in Southeast Alaska are below 8 degrees, but lately, especially in the last 15 years, we’ve seen a trend towards increasing sea surface temperatures in the winter time.”
Because data is fairly new, scientists aren’t sure of the implications.
Southeast Alaska Tribal Ocean Research, partnered with Haines’ Chilkoot Indian Association, has collected PSP data with regular testing since 2015, with the goal to improve tribal access to traditional foods.
Wright hypothesized that Haines’ levels could be killing certain species, like clams and salmon.
“There’s not much of a clam resource in Haines and think it’s because PSP levels are so high, they actually kill the clams if they get high enough,” Wright said.
He added that the toxins are possibly killing salmon, without making their eggs or meat toxic.
The highest level of PSP in mussels ever recorded in the state was in Haines’ Viking Cove in 2014, when levels tested at 21,600 micrograms per 100 grams— or 270 times above consumable levels.
The Alaska Department of Health and Social Services warn residents that “anyone consuming non-commercial shellfish does so at his or her own risk.” There is no safe season to consume non-commercial shellfish, and PSP toxins are not destroyed by heating or freezing.
Commercially harvested shellfish are deemed safe for consumption because of state testing requirements.
PSP can cause paralysis by blocking sodium channels in neurons. Early symptoms include tingling of the lips and tongue to tingling of fingers and toes, and can progress to the loss of muscle control in arms and legs. If chest and abdomen muscles become paralyzed—which can happen within 20 minutes of ingesting toxins—victims can die within hours.
Suspected victims of PSP should immediately call 911, and report cases to the State of Alaska Section of Epidemiology at 907-269-8000 or after hours at 1-800-478-0084. There is no antidote for PSP toxins, but victims can be saved with respirators if their breathing muscles become paralyzed.