Think twice about eating butter clams harvested in the area, particularly in Viking Cove, where there’s a shellfish advisory in place.
The Southeast Alaska Tribal Ocean Research network or SEATOR, posted the Haines-area advisory in early August. But there are several others in place, including one that went out just last week and impacted Ankau and Puget Cove beaches in Yakutat.
The advisories are based on shellfish and phytoplankton observations in locations where SEATOR partners collect samples from local beaches to track harmful algal blooms and marine biotoxin risks in southeast communities.
The warnings are designed to get people thinking about the risks of getting PSP, or paralytic shellfish poisoning, a severe – potentially fatal – illness that can come from eating contaminated shellfish.
Harmful Algal Blooms
To understand where PSP comes from, it’s helpful to look at what shellfish eat.
Bruce Wright, a senior scientist for the Knik Tribe who leads PSP monitoring efforts across the state, said harmful algal blooms are caused by phytoplankton – microscopic, plant-like organisms that are present in all the world’s oceans and major bodies of water.
“[There’s] one organism in particular, it’s a microscopic plant, you can’t see the thing without a microscope. And it’s called the dinoflagellates,” – think marine plankton. “And its name is Alexandrium,” he said.
Alexandrium is found globally in coastal waters and it is impacted directly by water temperature.
The warmer ocean temperatures get with climate change, the duration, frequency and distribution of harmful algal blooms increase. But there are other things that impact how much Alexandrium is in the water, like nutrients or the influx of freshwater.
“And since the Southeast Alaska shoreline is so convoluted, and there’s all these rivers and glacial water coming in, every location is different,” he said.
The more algae, the more food for shellfish – who are filter feeders. Shellfish pump water through their systems, filtering out and eating algae and other food particles. When shellfish eat Alexandrium and other biotoxin-producing algae, the toxins or paralytic shellfish toxins (PST), can build up in their tissue.
Wright recalled a 2010 incident of a commercial fisherman’s death originally classified as a result of PSP.
“A gentleman was eating Dungenous crab, and he ate what I call the crab butter in Haines,” he said.
Crab butter is the yellow-white-greenish viscera or guts after the shell has been removed. It’s actually a digestive gland known as the hepatopancreas, an equivalent to our liver and pancreas.
“And that’s the place in crab where the PSP levels are the highest. In fact, I don’t think we’ve ever even detected [PSP] in the crab meat in the leg, meat body, body meat, and [the commercial fisherman] died,” Wright said.
Although the Department of Health and Social Services said all of the man’s symptoms were consistent with PSP, the state medical examiner concluded the 57-year-old fisherman died from heart disease.
Alaska has a long history with PSP, with the earliest recorded cases dating back to the 18th century. The first human deaths attributed to PSP and a harmful algal bloom occurred in Southeast Alaska in 1799, near Sitka, when more than 100 members of explorer Alexander Baranof’s crew died after eating contaminated shellfish.
Monitoring
Wright, along with two other colleagues, conducted a study in the Haines area to monitor PSP sites using blue mussels.
“Because blue mussels when there’s a PSP event, their levels come up quicker than other organisms, because the water is so fresh for all the inflows and then they defecate quickly, so the levels come down quickly,” he said.
Simply put – scientists can see when the bloom started, ended and the severity of the bloom just by monitoring mussels on a weekly basis.
The FDA’s safe limit of consumption cutoff for PSP is 80 micrograms per 100 grams of tissue. So anything over 80 is considered unsafe by the FDA, said Wright. “We had blue mussels at 22,400 [micrograms]. Which [in this case] one mussel could kill a guy, no problem.”
Wright said he doesn’t have funding to conduct weekly testing but people can provide samples if they suspect levels are high. Also, the warmer the water temperature, the higher the chances of increased PSP levels.
“All I can say is generally Southeast Alaska, water temperatures have warmed up from Metlakatla north, and the PSP levels have expectedly risen from from south to north. And now if you look at sea surface temperatures you can see that the warm waters propagated up past Kodiak and as they propagated along the Alaska Peninsula,” he said.
And, it’s not just humans that are affected by PSP. Wright recalls collecting samples in Sand Point, by Popof Island in the Aleutian Islands. A woman was talking to Wright about PSP.
“Her dog will often run from the Sand Point over to Sand Dollar Beach, and watch her boat while she’s out there fishing,” he said. “And she could see the dog on the beach and then she saw the dog fall over. And so she pulled her nets out, took her skiff and got to the beach and the dog was dead.”
Wright said the dog had been eating sand lances. “And I’ve tested sand lances from that beach in the past and they were moderate levels of PSP.”
PSP in dogs
Although there have been some cases of dogs getting PSP in the past, there haven’t been any reports recently, according to Dr. Toccoa Wolf, owner and veterinarian of Sitka Animal Hospital.
“I haven’t seen any yet this summer, but it tends to be when they start seeing them. I’ll see multiple [cases] at a time,” she said.
Wolf said the challenge is figuring out if it is PSP in animals. “There’s no test we can run, there’s no blood test where we can say ‘yep, it was PSP’. We basically have to go off the history of the owner, and usually that was walking with my dog on the beach, and then they collapsed or then they vomited,” she said.
Wolf also said what makes it more difficult is that the dogs normally come in minimally conscious or they are in and out of consciousness. “We don’t see such severe cases where they need to be on ventilation, it’s usually more like, we have to support the pet through the toxin,” she said.
That includes controlling the vomiting because they can aspirate and have a lot of paralysis.
“We have to keep them warm, give them IV fluid, and just really support them through it, but there’s no antidote,” Wolf said.
She said that often pets will snap out of it 12 hours after treatment.
Wolf said she wants pet owners to be aware and it doesn’t mean pet owners can’t take their dogs to the beach. “The waters are tested and warnings are posted. I know recently in my neighborhood [in Sitka], at the very end of our road, it was one of the only areas known to have PSP in our community,” she said. “I just didn’t want my dog off leash there because he eats everything. I didn’t want him to eat a bunch of mussels or shellfish and get sick.”
She urges pet owners to be aware of the warnings and if the levels are high, keep that in mind and realize it is part of the risk of living in a coastal area.
Wolf said that PSP symptoms can be the same as a lot of other toxins. So if your dog was on the beach and suddenly lost consciousness, take it seriously. “It could be something totally different. Make sure you get them to a veterinarian. Get a diagnosis because there’s subtle signs that can differentiate it from other diseases that won’t just wear off after a few hours. So get them to a vet.”
It’s a treatable illness in dogs, according to Wolf. “I think it’s more just knowing and it’s something to be aware of, but I wouldn’t let it majorly affect the lifestyle with my dog at this point.”
Wright also adds that if there’s dead fish on the beach, don’t let your dog eat it. “Sand lance is a really important forage fish, lots of animals eat sand lances. If they’re high in PSP, it can take out animals.”
Food Web
Wright has studied and tested salmon all around the state, including in freshwater systems. He has found PSP in all five species of salmon. “Sometimes it exceeds the FDA limit for safe consumption. I think [they] are getting PSP from eating PSP-contaminated sand lances.”
He said he doesn’t have a lot of data on their diet when it comes to PSP. “I don’t even know if it’s affecting the salmon. We need to do a lab study.”
Wright has asked another colleague to do some lab studies on what levels of PSP it takes to kill a salmon. But they haven’t been done yet.
PSP has been detected in other species. Wright said that moderate levels of PSP can kill seabirds, including ducks. He also thinks sea otters are at risk.
Wright is working with the National Park Service sampling along the Gulf of Alaska. “They sample mussels and they’re also interested in the viability of the wolves that are out there and some of the wolves hunt along the shoreline.”
According to Wright, wolves might eat bivalves – mussels and clams – so they are testing their scat.
“We’ve got really high levels in some of the wolf scat,” he said. “We don’t know if that’s affecting the wolves. We don’t know the exact source. We’re working on analyzing some data from some of the wolf scat that’s been collected in the past and we’ll look at the individuals because they’ve done the DNA.”
They are measuring PSP in wolves by studying their poop.
“And try to correlate their diets with the PSP levels in their poop to give us an idea if there’s a risk to wolves,” Wright said.
There’s risks to everyone in the food web if PSP levels get high enough, according to Wright.
The state’s Division of Environmental Health’s laboratory is the only certified lab in the state for testing PSP. Wright said that they are contracted and budgeted to do as many as 1,500 samples a year. Included in the budget is shipping of the sample.
So if somebody wants to eat shellfish, clams, mussels, scallops, or crab guts [crab butter], “what they can do is they can make a collection and then send us a subsample before they eat it. And if the sample is about a cup, 100 grams or more, then we can do a test called mouse bioassay. And get them the results back in a day or two. And that’s and all those services are free, and we’ll, we’ll send them the results. And we’ll explain what risks there are for them consuming that food,” he said.