Paralytic Shellfish Poisoning and Domoic Acid in Alaska
Paralytic shellfish poisoning or PSP, originating from toxic algae blooms of the dinoflagellate Alexandrium has been a threat to public health of shellfish consumers in Alaska for centuries. The potential for PSP occurrence, as a result of climate change is a growing health concern to the coastal Alaska Natives, particularly Aleut communities where the problem is known to occur. As subsistence users, Aleut people rely on their local knowledge to determine whether it is safe to consume shellfish. Local knowledge presumes that PSP occurrence is a summer event and can be identified by a red color in the water termed a “red tide.” Local and traditional knowledge may assist in reducing the health risk, but in Alaska PSP illness occurs off season and toxic blooms may be colorless.
Paralytic shellfish poisoning is caused by naturally occurring toxins produced by a small marine plant, or phytoplankton, called Alexandrium. Every year coastal Alaska has PSP blooms; some years are worse than others. PSP levels can sicken wildlife and people and both can die if the PSP levels are high enough. The most common manner people get sick from PSP is from eating PSP-contaminated shellfish, mussels, clams and scallops which filter the PSP-producing organism, Alexandrium sp., from the ocean. Small marine animals called zooplankton, which include the copepods, eat the Alexandrium and concentrate the PSP toxins.
Sand lance or sandlance are also known as "sand eels" or “needle fish” gets its name from its slender body and pointed snout. Sand lance primarily feed on copepods and may become toxic with PSP because the copepods are toxic from eating the organism that produces PSP.
Many of the marine predators in the North Pacific Ocean depend upon sand lance as an important food source. Sand lance are high in energy, mostly in lipids (fats), and sand lance they contain many important nutrients. Some of the predators that feed on sand lance are whales, sea lions, seals, sea otters, marine birds, and fish including salmon and halibut. PSP affects the central nervous system so when sand lance become contaminated with PSP they may lose their ability to swim and they may not be able to avoid predators. In Alaska’s Taiyasanka Harbor Dungeness crab became so contaminated from eating dead PSP-contaminated sand lance and mussels they were toxic enough to sicken people, and sea birds have been reported to have died on Kodiak Island and in the Aleutian Islands from eating contaminated sand lance.
Climate change also increases variability of weather and extreme events, especially in the transition months in spring and fall making it difficult to correctly identify any time frame for gathering shellfish. The net result is that traditional knowledge that people rely on for subsistence harvest, in the context of climate change, is insufficient to protect public health. In the absence of any state sponsored PSP monitoring program to protect subsistence harvesters, supplementing traditional knowledge with conventional scientific research through a complementary approach is necessary to further reduce the PSP risk and increase communities’ adaptive capacities to climate changes. The approach used in the Aleutian Pribilof Islands PSP program was to educate residents about the causes of PSP and train them to monitor shellfish toxicity in addition to using traditional observations. The combined effort should help them to identify the potential threat and reduce the threat of PSP poisoning. A similar approach was used in the domoic acid research effort.
Click here to see the PSP data collected by the Aleutian Pribilof Islands Association.
Click here to see the award the Aleutian Pribilof Islands Association received from their work on PSP and publications.
Click here to learn about Aleutian Pribilof Islands Association's work on domoic acid.
Paralytic shellfish poisoning is caused by naturally occurring toxins produced by a small marine plant, or phytoplankton, called Alexandrium. Every year coastal Alaska has PSP blooms; some years are worse than others. PSP levels can sicken wildlife and people and both can die if the PSP levels are high enough. The most common manner people get sick from PSP is from eating PSP-contaminated shellfish, mussels, clams and scallops which filter the PSP-producing organism, Alexandrium sp., from the ocean. Small marine animals called zooplankton, which include the copepods, eat the Alexandrium and concentrate the PSP toxins.
Sand lance or sandlance are also known as "sand eels" or “needle fish” gets its name from its slender body and pointed snout. Sand lance primarily feed on copepods and may become toxic with PSP because the copepods are toxic from eating the organism that produces PSP.
Many of the marine predators in the North Pacific Ocean depend upon sand lance as an important food source. Sand lance are high in energy, mostly in lipids (fats), and sand lance they contain many important nutrients. Some of the predators that feed on sand lance are whales, sea lions, seals, sea otters, marine birds, and fish including salmon and halibut. PSP affects the central nervous system so when sand lance become contaminated with PSP they may lose their ability to swim and they may not be able to avoid predators. In Alaska’s Taiyasanka Harbor Dungeness crab became so contaminated from eating dead PSP-contaminated sand lance and mussels they were toxic enough to sicken people, and sea birds have been reported to have died on Kodiak Island and in the Aleutian Islands from eating contaminated sand lance.
Climate change also increases variability of weather and extreme events, especially in the transition months in spring and fall making it difficult to correctly identify any time frame for gathering shellfish. The net result is that traditional knowledge that people rely on for subsistence harvest, in the context of climate change, is insufficient to protect public health. In the absence of any state sponsored PSP monitoring program to protect subsistence harvesters, supplementing traditional knowledge with conventional scientific research through a complementary approach is necessary to further reduce the PSP risk and increase communities’ adaptive capacities to climate changes. The approach used in the Aleutian Pribilof Islands PSP program was to educate residents about the causes of PSP and train them to monitor shellfish toxicity in addition to using traditional observations. The combined effort should help them to identify the potential threat and reduce the threat of PSP poisoning. A similar approach was used in the domoic acid research effort.
Click here to see the PSP data collected by the Aleutian Pribilof Islands Association.
Click here to see the award the Aleutian Pribilof Islands Association received from their work on PSP and publications.
Click here to learn about Aleutian Pribilof Islands Association's work on domoic acid.