Paralytic Shellfish Poisoning (PSP) and Harmful Algal Blooms (HABs)

Certain kinds of algae produce toxins that can contaminate shellfish and other marine wildlife. The consumption of these contaminated wildlife can result in sickness and death. There is a wide variation in how different species of shellfish concentrate and retain toxins.

It is important to be aware that:

  • Most harmful algal blooms cannot be seen in the water. In other words, there is not a red tide.

  • PSP toxin levels in shellfish can be different between species, from one beach to the next, and from one day to the next. 

  • People cannot see, smell, or taste if toxins are present in shellfish or other food species.

  • Cleaning, cooking, freezing, or aging contaminated shellfish and other animals does not reduce the health risk.

The US Food and Drug Administration has set regulatory limits of 80 μg toxin/100 g shellfish tissue for paralytic shellfish toxins. Shellfish with higher levels of toxins are unsafe to eat.

Lab Results

The Qawalangin Tribe of Unalaska and three other sister tribes in the region (the Aleut Community of St. Paul Island, Agdaagux Tribe of King Cove, and Qagan Tayagungin Tribe of Sand Point) are collecting samples and sending them monthly for laboratory analysis of the toxins that cause PSP. We are trying to understand the general presence of PSP toxins in our shellfish and the presence of harmful algae in the water. This work is funded by NOAA National Centers for Coastal Ocean Science.

Due to the very specific nature of toxins and the delay between collecting samples and getting results, these results are not an indication of food safety.

When results are returned to us, we will share them here on this page.

The Qawalangin Tribe of Unalaska neither encourages nor discourages the consumption of locally harvested shellfish, but provides this information for community members to make their own educated decisions about shellfish consumption.

Learn more about Paralytic Shellfish Poisoning

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