By Jenny Neyman
Clam diggers beware: Any recreationally harvested shellfish collected any time, on any beach in Alaska could be contaminated with toxins that cause paralytic shellfish poisoning. Eating such shellfish — including clams, mussels, oysters, geoducks, scallops and the guts of crabs — could potentially result in sickness or even death.
The number of cases of PSP in Alaska is a tricky number to track. According to the Alaska Division of Public Health, two deaths in 1994 are directly attributed to PSP, and two more in 2010 are thought to at least have been exacerbated by PSP sickness. And the number of reports of highly likely PSP cases or cases confirmed by lab tests in the last 10 years is 45, ranging from none in 2008 to as many as 26 in 2011. And the assumption is that cases of PSP are underreported, meaning it’s likely more common than the statistics reflect. Medical providers in Alaska are good at recognizing symptoms and reporting possible outbreaks, said Michael Cooper, Infectious Disease Program Manager with the Alaska Division of Public Health. But many times people eating contaminated shellfish and feeling just a little sick won’t go to a doctor nor call the state to report their condition, Cooper said.
“They will go out, eat some clams, have really minor symptoms — maybe get a funny tingling on their lips — then will just sort of wait and get better and won’t seek care, and we’ll never hear about it,” he said.
The underreporting problem complicates being able to tell how big a risk PSP is in Alaska, though enough cases still are reported to keep state health departments on their toes. A probable case of PSP was reported from clams, likely surf clams, harvested June 15 at Clam Gulch. Test results for toxins in other sample clams taken from that beach are pending.
But one thing’s for sure — whether or not PSP ever crops up and sickens anyone, clamming definitely results in heartburn for the state agencies that deal with recreational shellfish harvesting, because even though managers and biologists realize that recreational clamming is a lawfully permitted, greatly enjoyed activity for many Alaskans, there simply is no way to guarantee the safety of those who participate in it.
“Our caution, our warnings exist all the time because you can never know when one clam or cockle or muscle is safe or not,” said Greg Wilkinson, Alaska Department of Health and Social Services spokesman.
Such a dire warning for an activity so mellow that whole families routinely participate — from elders to kids just barely able to toddle. It’s not like hunting wildlife that can bite or scratch back, braving rough water to haul in a halibut, wading into berry patches in bear territory or any number of other pursuits by which Alaskans gather food from the land. At worst shellfish harvesting is dirty, damp work, but it’s not like clams have claws, or that mussels have the muscle to put up a fight. So why the “woe-to-you, proceed at-your-own-risk,” warnings?
It’s because PSP is a serious illness with no antidote, no way to predict when or where it might show up and, even worse, no way for harvesters to easily tell if their haul is “hot” — affected by PSP-causing toxins — or not.
PSP is caused by eating shellfish contaminated with dinoflagellate algae that produce toxins harmful to humans. Early symptoms include tingling of the lips and tongue, which can start within minutes of consuming contaminated shellfish or can take an hour or two to develop. The tingling can progress to the fingers and toes, followed by loss of muscle control in the arms and legs, and sometimes even the muscles of the chest and abdomen can become paralyzed. Nausea, headache and/or a sense of floating can occur, as can difficulty breathing. High toxin exposures can result in death in as little as two hours from paralysis of the breathing muscles.
The toxins affect mammals consuming them by blocking sodium channels in neurons, preventing the neurons from functioning normally and resulting in paralysis. Some of the toxins are 1,000 times more potent than cyanide, and toxin levels contained in a single shellfish can be fatal to humans, according to information from DHSS. Symptoms can pass on their own, but anyone who thinks they are experiencing PSP is advised to seek immediate medical treatment. There is no antidote to stop the reaction, but at least medical professionals could treat the symptoms and, in dire cases, hopefully keep patients alive if they do lose the ability to breathe on their own.
The Kenai resident reporting PSP on June 16 became ill overnight after eating clams harvested June 15 from Clam Gulch, exhibiting a floating sensation, tingling around the mouth, vomiting, headache and shortness of breath, according to DHSS. The man didn’t seek medical treatment so there was no urine sample taken to test for PSP, and there were no leftovers from the suspect clams to test for the toxins. Still, DHSS was quick to warn the public to be wary of the possibility of PSP.
“There’s no way to know when they’re safe, so please be cautious,” Wilkinson said. “… People want us to be able to tell them, ‘Is this one safe? Is that one safe?’ and we can’t. You could take a dozen clams out of the ground but we can’t tell you which ones might have the toxins. Each one is a risk.”