High PSP levels in clams

Observation: The paralytic shellfish poisoning (PSP) results for the King Cove Lagoon, Alaska (butter clams collected 10/22/2013) had PSP toxin levels of 108 micrograms/100 grams which exceeds the FDA limit of 80 micrograms/100 grams. See the data on the attached graph or the web page link. PSP levels will likely be different in adjacent beaches and will change with time. Littleneck clams usually do not reach as high of toxicity levels as butter clams and littleneck clam toxicity levels usually drop off quicker than butter clams. If you harvest/consume clams from Alaska beaches you should become familiar with all the clam species. Extreme caution should be taken when consuming any clams, scallops and mussels from Alaska’s beaches. Shellfish harvesters should be advised that paralytic shellfish poisoning (PSP) is a serious health risk when consuming personally harvested shellfish. Crabs feeding on toxic mussels, clams or fish (sand lance) can accumulate PSP toxin in their digestive system, so I recommend that before cooking, remove the back shell of the crab and clean out all the dark soft tissues that comprise the digestive system and crab butter. Shellfish sold at wholesale and retail markets require PSP testing and are considered safe for human consumption. I have recently discovered that forage fish (capelin, herring and sand lance) may feed on the PSP producing algae and become toxic too. I recommend not eating dead or sick looking forage fish found on Alaska beaches and report these events to me. I will be investigating forage fish toxicity by PSP in 2013-2014. The samples for this project are all analyzed by the Alaska Department of Environmental Conservation using approved analytical methods. Note that the FDA limit for PSP is 80 micrograms/100 grams, the red line on the attached graph. The data collection for this project will continue to Fall 2014. Data tables are at link. Past and current funding for the PSP project provided by Alaska Recreational Shellfish Pilot Program, Region 10 U.S. Environmental Protection Agency (IGAP), North Pacific Research Board, NOAA Monitoring and Event Response for Harmful Algal Blooms (MERHAB) Research Program and the Aleutian Pribilof Islands Association. Bruce Wright, LEO

Consult: has shared this observation with the Alaska Department of Environmental Conservation Food Safety Program, and with the State of Alaska Department of Public Health.