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


If you choose to harvest please know the signs and symptoms of PSP and call 911 if you think you have PSP.


Updated June 19, 2022: Lab results indicate toxin levels have elevated for the season. Please use extra caution. 


2022 Data Table (check back weekly for updates):





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.

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.


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.

2022 data updated 30Aug2022.PNG

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.

Staff members of the Qawalangin Tribe of Unalaska  are collecting blue mussel samples weekly and sending them to Anchorage for laboratory analysis of the toxins that cause PSP. We are trying to understand the general presence of PSP toxins in our shellfish. 


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.

We will also collect water samples and examine them under a microscope to understand the presence of harmful algae in the water. These phytoplankton tows are a pilot study new in 2022, with support from Alaska Conservation Foundation and Alaska Ocean Observing System


Lab Results

Summary graphs from 2020 and 2021 are below. 

For more information please contact

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