Project Tests Alaska Clams for Paralytic Shellfish Toxins
First time for recreational shellfish testing in state
NINILCHIK - In Alaska there’s nothing quite like digging for your dinner.
“Some beaches are easy and some are much more difficult. In the Ninilchik area it’s relatively easy clam digging where a person can get their harvest of clams pretty easily,” said Darrel Williams of the Ninilchik Tribal Council.
Beaches around Ninilchik and Homer are summer hotspots for recreational clamming. The clams coming out of Alaska’s waters, however, have never been tested for paralytic shellfish toxins (PST) until now.
“This project is critical to start a baseline so that we can start understanding how much toxins are in our clams. Do we have an issue? We don't even know if we do or not so this starts getting that baseline,” said Terry Thompson, the Kachemak Bay Research Reserve Manager.
The three-year, $120,000 “Recreational Shellfish Beach Monitoring Pilot Program” will test shellfish from around the state for PST. The Alaska Department of Environmental Conservation, Division of Environmental Health solicited proposals from government agencies that wanted to participate in the program.
The Southern Kenai Peninsula is the largest area of the study with clams coming from Ninilchik, Homer, Port Graham and other spots around Kachemak Bay. Haines, Kodiak and Sand Point are also testing on a smaller level.
Paralytic shellfish poisoning (PSP) happens when clams or mussels ingest toxic algae blooms, and anyone who eats that shellfish could get very sick and, in extreme cases, die.
“It can happen in a matter of hours. It's one of these things where long days and lots of extra sunlight increase the chances for a bloom,” said Williams.
The Kachemak Bay Research Reserve Partnered with several agencies, including the Ninilchik Tribal Council, to test for the toxins. Thompson’s group sent three sample batches to the State Environmental Health Laboratory in Anchorage throughout the summer.
Lab technicians liquefy the clams or mussels then add acid to simulate human digestion. The mixture is boiled for five minutes, which makes the toxins more potent for testing.
Microbiologists skim the final serum off the top of the sample and inject it into the abdomen of mice. If the rodents live five to seven minutes after the injection, the shellfish didn’t contain any detectable amounts of PST.
“Any sooner than that and it means we need to start diluting it to figure out the exact toxicity and we need to start letting people know they're unsafe,” said microbiologist Brian Watt.
While Alaska’s oceans are too vast to regularly test recreationally harvested clams, researchers say this is the first step to figuring out what’s in the water of the Last Frontier.
All samples from the Southern Kenai Peninsula testing areas came back with no detectable levels of PST.
Thompson says this pilot program is not meant to certify Alaska’s beaches as “safe,” because a toxic bloom could happen at any time. He says the only shellfish that’s always safe to eat is that that comes from commercial farms because the clams are tested on a regular basis.