Testing all clams

• Study looks to establish baseline for toxins
By Naomi Klouda
Homer Tribune

HOMER TRIBUNE/file photo - Digging clams on the Kenai Peninsula is often a family outing. A new study should tell more about instances of elevated toxins, if any.

HOMER TRIBUNE/file photo - Digging clams on the Kenai Peninsula is often a family outing. A new study should tell more about instances of elevated toxins, if any.

People loving the Kenai Peninsula in summer for the famous kings get most of the attention, but a less-discussed reason that packs the Kenai Peninsula highways point to the rich clam beds.
Whether the shellfish from Ninilchik to Port Graham is safe from various levels of toxins, however, has never been extensively tested until this summer.
Thanks to a three-year study and $120,000 awarded to the Kachemak Bay Research Reserve, shellfish on all the main beaches were tested in July and August and will continue to be tested for the next three years.
Terry Thompson, director of KBRR, said the project is significant because for the first time, the data will collect into a baseline study to serve for years to come. So far, so good – tests showed no significant levels in shellfish tested for paralytic shellfish toxins.
“Last spring, the (Department of Environmental Conservation) put out a call for proposals looking for three coastal communities to do a baseline study of PCP in recreationally harvested shellfish, because these aren’t tested in Alaska for toxins,” Thompson said. “The DEC will always tell people ‘if you harvest shellfish, you do so at your own risk. To be safe, you need to buy them from a retail outlet that has their product tested.’ But thousands of people harvest shellfish in Alaska. The Legislature put some funds out to do an RFP.”
Alaska Department of Environmental Conservation, Division of Environmental Health, solicited proposals from government organizations. KBRR was selected to conduct the program and commit to a three-year period of collaborative activities.
The partners are the Ninilchik Traditional Council, Port Graham Village Council, Seldovia Village Tribe and NOAA’s Kasitsna Bay Lab and Department of Fish and Game in Homer, and local volunteer Nicki Scarzi and Kachemak Bay Wilderness Lodge.
“They all go out once a month during the lowest tides from May to September to harvest shellfish,” Thompson said. Depending on the native location, they harvest razor clams, butter clams, little neck clams or mussels. So far, they have had two monitoring events, one in July and one in August.
All shellfish must have less than 80 micrograms of paralytic shellfish toxins to be considered safe for human consumption. Using what’s called the mouse bioassay test, PSP levels below 34 micrograms cannot be detected. Anything below 34 micrograms is undetectable, meaning the food is safe. Shellfish containing 80 micrograms of PSP are unsafe for humans.
“Another aspect that made this study exciting was in the timing. I had received an email from Chief Norman out of Port Graham. He said they hadn’t been harvesting clams. Now that they hadn’t harvested for many years, they were starting to see more clams, and wanted to start harvesting again as a subsistence foods. They were curious to see if there was potential problems with PSP,” Thompson said.
Chief Norman is one of the shellfish monitors. “We haven’t harvested them here for 25-30 years. On minus tides, we used to get cockles and butter clams. Then suddenly they disappeared,” Norman said. “We haven’t figured out what happened. This testing will help in one question. We want to know if they are safe.”
Testing clean of toxins doesn’t certify whole beaches. But it does construct the baseline of information so they can document incidences of elevated toxins.
“That’s because the test is only as good as the tide we collect it on. If we do it on Saturday, it may be 10 days before we get results back,” Thompson said. “Each tide changes the dynamics of potential toxins in clams.”
Scientists know Kachemak Bay waters are safe when it comes to oyster harvests because oysters are always tested.
“But we don’t know if the clams take on toxins the same way as an oyster,” he said.
This study is correlating well with Catie Bursch’s KBRR community monitoring study on phytoplankton and the search for harmful algae blooms.
“There are no high levels of dinoflagellates in the water – a species that causes PCP. Alexandrium is one species of dinoflagellates that we are really interested in,” Thompson said.
It’s also important to become more familiar with PSP levels in Kachemak Bay and along Cook Inlet because there have been several deaths to PSP in the past on nearby Kodiak. Up to 20,000 micrograms of the toxin have been measured in shellfish there – remembering that 80 micrograms is the point where it’s no longer fit for human consumption.
“These were tested at very high levels,” Thompson said. “We’ve taken our assumptions based from oyster farmers, but we don’t know if they take on PSP at the same rate. We have very heavy use of our shellfish. A lot of the folks from Anchorage and the Mat Su come down, as well as people on the Peninsula, to harvest.”
People may have gotten sick at times from shellfish eaten on the Peninsula. But there have been no visible, dramatic outbreaks here that have been documented, Thompson said.
“It’s a pilot project. As we learn more, we can modify what we are doing. One of the things of real interest, because there have been no tests of butter clams, is that they can hold their toxins for two years. By studying them, we can look into a window in the past.”
Each month during the testing, KBRR will make the results known to the public.

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Posted by on Sep 5th, 2012 and filed under Headline News. You can follow any responses to this entry through the RSS 2.0. Both comments and pings are currently closed.

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