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For current information about shellfish toxin levels and advisories, see the AHAB website.

Shellfish Poisoning Resources

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 on. 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. This event is called a Harmful Algal Bloom, or HAB.

There are two main kinds of shellfish poisoning that affect people, called Paralytic Shellfish Poisoning (PSP) and Amnesic Shellfish Poisoning (ASP). There is also a less dangerous kind called Diarrhetic Shellfish Poisoning. Information about 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.

If you are looking for information about fish poisoning, such as ciguatera or scombroid, please go to this page.

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.

Diarrhetic Shellfish Poisoning

As the name suggests, Diarrhetic Shellfish Poisoning has gastrointestinal symptoms, predominantly nausea, vomiting, abdominal cramping, and diarrhea. While the symptoms can be severe, they are not life-threatening and patients typically recover in a few days. DSP is caused by eating shellfish containing algae from the genus Dinophysis.

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

Press Releases and Public Service Announcements







Previous Alaska DHSS Press Releases

Epidemiology Bulletins