• Paralytic shellfish poisoning – caution urged for recreational harvesters
By Jenny Neyman
Special to the Tribune
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 is 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 is 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 mussel 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. 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.
Complicating matters are lingering old wives tales of ways harvesters can tell if their shellfish are safe to eat. According to DHSS, all the following are misconceptions:
It used to be thought that keeping an eye out for a “red tide” – an algae bloom causing a red tint to the water – would indicate when shellfish are contaminated. Not true, says DHSS. For one thing, the reddish coloration to the water more commonly comes from a bloom of nontoxic organisms, not the ones that cause PSP.
The toxins causing PSP can be present even when the water is clear, and can linger after the algae bloom, which may or may not be visible, is over. Shellfish are filter feeders, after all, and some take in more of the PSP-causing toxins than others, and have different rates of purging themselves of the toxin. Furthermore, one clam on a beach could be fine while another is not. There’s no way to know by just looking at a clam or its surrounding environment whether it’s “hot.” The only sure way is laboratory testing.
“Different species of shellfish take in and retain those toxins at different levels. The other thing is Clam Gulch is a very large, long beach. You could have a section of beach that could be toxic, and a mile down the beach could not be toxic,” said Terry Thompson, statewide communications and outreach coordinator for the Alaska Department of Fish and Game Sportfish Division.
It also used to be thought that shellfish could be safely harvested in colder months – months with an “R,” from September to April. Also not true, as there have been cases of PSP in Alaska reported year-round. There might be less risk of a PSP outbreak in colder months, but the risk remains.
PSP-causing toxins can’t be cooked or cut out, as sometimes is believed. Neither cooking heat nor freezing kills PSP toxins.
Rubbing a clam on your lips to see if they start tingling before eating the meat also isn’t a safe bet. PSP manifests through consumption. Surface contact with the toxin might not be enough to trigger the response that ingesting will.
So why, then, if recreationally harvested shellfish is always at risk of causing PSP, is commercial shellfish safe to eat? That’s because commercially available shellfish is required to undergo routine testing to ensure it isn’t contaminated. But such a monitoring system simply isn’t feasible for recreationally harvested shellfish in Alaska. There’s just too much to test and not enough money and resources to do it, Thompson said.
“Without a very targeted monitoring program and a very targeted harvest program we have to be very careful. The message from the Department of Environmental Conservation is that clamming in Alaska is an at-your-own-risk activity because beaches are not tested unless it’s a commercial operation. It’s just the reality of thousands of miles of coastline. It would almost be impossible to try to certify beaches.”
There is, however, a pilot project underway to get a better sense of PSP levels in recreationally harvested shellfish in Alaska. The Alaska Legislature awarded money for a three-year monitoring project starting in 2012 for coastal communities to test popular shellfish areas for PSP-causing toxins, in order to start to from a baseline of data. Four areas are participating – Sand Point, Haines, Kodiak and Cook Inlet, particularly around Kachemak Bay.
The Cook Inlet testing has been done from Clam Gulch south through Kackemak Bay through a collaboration of efforts, including the Ninilchik Traditional Council, Port Graham Village Council, Seldovia Village Tribe, NOAA’s Kasitsna Bay Lab, the Kachemak Bay Wilderness Lodge and the Department of Fish and Game. Thompson originally headed the project through the Kachemak Bay Research Reserve, though now is with Fish and Game.
Thompson said that, so far in the testing data collected in 2012 and 2013, no significant levels of PSP toxins were found in any of the shellfish tested in Cook Inlet. But that doesn’t mean there couldn’t be.
“We’ve never seen any levels elevated to any point that would give us pause,” he said. “That’s why to have a potential situation (like the one at Clam Gulch) was a bit of a surprise. But without monitoring, you really wouldn’t know if you’re having a potential toxic event or not.”
He stressed that the project is not about comprehensive monitoring and the data shouldn’t be taken to judge whether a beach is safe from PSP. It’s just to start to form a baseline of data. Even at that, funding expires this year, so 2014 will be the last summer in which testing is done, unless the Legislature decides to renew the funding.
“The premise of the recreational shellfish monitoring program is to build a baseline, we are not trying to certify beaches as safe. The testing is done to try to understand if there are levels of toxins present and what kind to establish a baseline of data,” he said.
Thompson happened to be on the peninsula when the Clam Gulch PSP case was reported, so he headed to the beach to take samples for testing. In looking at what clammers were harvesting in the area, he thinks the initial report of the clam in question might have been in error. Initially DHSS said the man reported getting sick after eating a butter clam, but Thompson thinks it was actually a surf clam, found with much less frequency on popular Cook Inlet clamming beaches than the more-abundant razor, butter and little-neck clams. Smaller surf clams are easier to identify, Thompson said, but in larger sizes surf clams are triangular shaped and can look similar to butter clams.
“I think our educated guess is it was probably misidentified. There’s not a lot of butter clams at Clam Gulch,” Thompson said.
Samples were sent off for testing. A DHSS representative said Monday that the results had not yet come in, but are expected this week. Luckily, the clammer reporting the PSP event was OK, and no other cases of suspected PSP have been reported. But still, Thomspon said the incident should serve as a good reminder to people to take care when eating recreationally caught shellfish in Alaska. Don’t eat alone, he said, and immediately seek medical care if symptoms start to develop.
“It’s a very complicated situation. We want people to be safe. That’s the bottom line – be knowledgeable, be safe,” he said. “PSP toxins can be fatal. People die in Alaska from eating contaminated shellfish, so it’s not something you want to leave to chance.”
Jenny Neymen is the publisher of the Redoubt Reporter.
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