Just back from the beach in Sand Point, Jackie McConnell carried a bucket of clams and cockles into her motel room at the Anchor Inn.
McConnell is the project coordinator for the Knik Tribe’s program for monitoring paralytic shellfish poisoning, or PSP — a dangerous and often fatal neurotoxin that can show up in local shellfish.
PSP is typically found during the warm summer months, but McConnell says the toxin has been showing up in butter clams and cockles for much longer.
“They are basically hot all year round,” she said.
McConnell was sorting through the bucket of shellfish with Bruce Wright, the tribe’s chief scientist. He’s studied PSP levels in Alaska for about 20 years. On this trip, he said he is particularly interested in Arctic surf clams — also called pink-neck clams — a favored food of walruses.
“There's people that, when they catch a walrus, they like to take the stomach and eat the undigested clams,” Wright said.
That’s one example of how saxitoxin moves through the food web — starting in shellfish, then traveling into larger animals. But the researchers say they’re also finding high levels of saxitoxin in animal droppings far from the coast.
“We're finding that wolves, bears, their scat in areas where they're not even feeding from the ocean, that they can have moderate levels of PSP in their scat,” Wright said.
They’ve concluded the inland contamination comes from cyanobacteria, a type of blue-green algae found in ponds and lakes. That suggests a second, freshwater source of saxitoxin is entering the food web.
Saxitoxin — one of about 50 neurotoxins found in shellfish — commonly accumulates in freshwater systems in the Lower 48, where warm weather creates favorable conditions for the bacteria. Its presence in Alaska’s cooler climates is relatively new.
Despite the elevated readings, the researchers said local shellfish can still be safe to eat if it’s been tested first.
“We'll pay for the shipping, we'll pay for the analysis, and we'll and we'll take care of that consultation after the data comes back,” Wright said.
He said residents can leave their harvest in a bucket and send a sample to the tribe. Results are typically returned within one or two days.
