The Alaska Department of Health and Social Services is warning residents in the Kachemak Bay area to exercise caution when harvesting wild shellfish. The department received two reports in late July from individuals experiencing symptoms consistent with paralytic shellfish poisoning.
“We had some people who had harvested some shellfish recreationally and felt the symptoms of PSP, tingling, light headiness, numb feeling around their lips. They had called and let us know about that,” Lousia Castrodale said, an epidemiologist with the state’s health department.
Castrodale explains it typically receives reports of PSP cases from healthcare providers. Neither report has been confirmed by a doctor, but Castrodale said the department wants the public to be aware of the risk. Both reports came from individuals harvesting shellfish in Tutka Bay and Sadie Cove.
The department reached out to the Kachemak Bay National Estuarine Research Reserve. The reserve tests 17 sites in Kachemak Bay for harmful phytoplankton blooms known to increase the risk of PSP. Rose Robinson is the reserve’s harmful species coordinator. She notes that levels of toxic phytoplankton have been rising throughout the season, but recent weather has led to perfect conditions for large blooms
“We’ve had rain events which have led to some different nutrients entering the water, and then we’ve had sunny days, and those can lead to perfect conditions for phytoplankton to bloom,” Robinson explained.
The reserve has tested muscles samples near Homer’s harbor, but those tests shown safe level of PSP toxins. Muscles are known to process those toxins quickly, but other species such as butter clams can hold toxins for up to two years.
Robinson adds that harmful algal blooms are a very localized issue, varying from bay to bay, but she said anyone harvesting in Kachemak Bay should do so with caution. She said the reserve can also coordinate testing of shellfish with people looking to harvest in a particular area. Both Robinson and Castrodale note that the risk is only for wild shellfish.
The National Oceanic and Atmospheric Administration’s Kasistsna Bay Laboratory near Seldovia has also been helping to monitor increased risks in both Sadie Cove and Tutka Bay. You can also check out risk indicator's at the laboratory's Harmful Algal Bloom Information System.