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Infectious Disease

Shellfish Poisoning Resources

crab pic.jpg For current information about shellfish toxin levels and advisories, see ​the AHAB website​.

General Information

Shellfish poisoning includes several types of illnesses caused by consuming shellfish that contain toxins. These toxins come from certain types of algae, which the shellfish feed o​​n. When toxin-producing algae "bloom", or have large increases in their numbers, the shellfish eating the toxic algae can accumulate enough toxin to be dangerous to humans and other animals that eat them. There are two main kinds of shellfish poisoning that affect people, called Paralytic Shellfish Poisoning (PSP) and Amnesic Shellfish Poisoning (ASP). Information about both of these conditions is described below. Several groups in Alaska test shellfish for toxin levels based on region of the state, see "Shellfish Monitoring and Advisories" below for details.

Harmful Algal Blooms (HABs) is a term used to describe the situation where toxin-producing algae (or algae that cause problems for other reasons) increase in numbers. HABs are a public health issue of their own, and more information about HABs and HAB monitoring in Alaska is also included below.
  • Know Before You Dig​ - Check this resource from Alaska DEC out before harvesting shellfish. Also check for recent toxin and HAB testing in the area you plan to harvest from at the AHAB website​.

Paralytic Shellfish Poisoning

Paralytic Shellfish Poisoning (PSP) is a serious illness that is caused by eating shellfish contaminated with dinoflagellate algae (e.g., Alexandrium spp.) that produce harmful saxitoxins. If you are experiencing symptoms of PSP, go to the emergency department immediately and notify public health.

Amnesic Shellfish Poisoning

Amnesic Shellfish Poisoning (ASP) is another serious illness that is caused by eating shellfish contaminated with diatoms from the genus Pseudo-nitzschia that produce the harmful toxin, domoic acid (DA). If you are experiencing symptoms of ASP, seek healthcare immediately and notify public health.

Shellfish Monitoring and Advisories in Alaska

Note: These links are provided for informational purposes only; they do not necessarily constitute an endorsement by the Alaska Division of Public Health.


HAB ​Information and Resources​

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