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NCCOS Project

Harmful Algal Blooms Event Response: Responding to Paralytic Shellfish Poisoning Outbreaks in Alaska

This project began in July 2011 and was completed in July 2011

We helped Alaska state regulators, the shellfish industry, and community leaders initiate routine, rapid screening of noncommercial shellfish in southeast Alaska for paralytic shellfish poisoning (PSP) toxins. We also worked with NOAA’s Weather Service to help Alaska's health officials broadcast PSP-related warnings.

Why We Care
Paralytic shellfish poisoning (PSP) threatens public health in Alaska and costs commercial shellfish fisheries, recreational harvesters, and the aquaculture industry more than $10 million annually. When shellfish feed on toxic Alexandrium algae, PSP toxins (called saxitoxins) accumulate in their flesh and viscera. Animals that eat shellfish with PSP toxins often become sick. Common symptoms include nausea, vomiting, diarrhea, and abdominal pain. The toxins can be fatal: in 2010, two Alaskans died from PSP symptoms after eating recreationally harvested shellfish. It has also been implicated in sea otter and other marine mammal deaths.

In Alaska, commercial shellfish are regulated by the state and are routinely tested. However, systematic testing is not available for thousands of miles of beaches that support recreational, traditional, and subsistence shellfish harvests. In the absence of an algae bloom early warning system, the toxic blooms often catch commercial shell fisheries off guard; often they lose money if they don’t harvest before the bloom strikes and the fishery closes.

What We Did
In July 2011, we provided Alaska state regulators, the shellfish industry, and community leaders with funding, training, and access to a network of our harmful algal bloom (HAB) experts. We helped initiate the first routine, rapid screening of noncommercial shellfish for PSP toxins in southeast Alaska. We also worked with NOAA’s Weather Service to help Alaskan health officials broadcast PSP-related warnings.

During a 2010 PSP outbreak in Alaska, our emergency funding program allowed experts from Washington State to demonstrate the use of an enzyme-linked immunosorbent assay (ELISA) technique for rapidly screening Alaskan shellfish samples for PSP. The ELISA method allows monitors to rapidly process large numbers of shellfish and seawater samples and isolate samples containing toxins. Contaminated samples are re-tested using the mouse bioassay, the approved method for justifying all state regulatory actions (e.g. opening or closing a PSP impacted shell fishery).

In 2011, we applied the technologies to help Alaskan communities identify toxic algae cells as a warning of future PSP events. Training workshops in southeast and central Alaska included the following proven HAB detection technologies:

  • ELISA for PSP toxin screening
  • Volunteer microscope-based cell identification
  • Quantitative real-time polymerase chain reaction (qPCR – a laboratory-based molecular cell detection method).

Our leadership via the HAB Event Response program drew in experts from the University of Alaska Southeast, the Alaska Harmful Algal Bloom Monitoring Program, and the NOAA Northwest Fisheries Science Center. Within NCCOS, we mobilized our Analytical Response Team, the Phytoplankton Monitoring Program, and our Kasitsna Bay Laboratory.

Our training opportunities benefited researchers and regulators from the Alaska Departments of Environmental Conservation, Fish and Game, and Health and Social Services; researchers and educators from the University of Alaska system; and industry representatives, including commercial shellfish fisheries directors, as well as shellfish farmers directly impacted by HAB events.

Next Steps
Our HAB Event Response Program continues to fund projects that support the well-established, rigorous state shellfish monitoring programs that protect human health, so consumers are assured that commercially available shellfish are safe for consumption.

Visit our Event Response page to apply for immediate assistance for managing events and advancing the understanding of HABs.

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