Monitoring Harmful Algal Bloom in Kodiak Waters

Four long-term sites on the Kodiak road system have been established for continuous monitoring of harmful algal bloom species; two sites each at Near Island's Trident Basin and Mission Beach. Monitoring consists of weekly phytoplankton samples and phytoplankton identification along with biweekly tissue samples collected on the beaches at low tide. Samples are sent to KANA's Tribal partners, Sitka Tribe of Alaska, where the tissue is processed and analyzed for Paralytic Shellfish Toxin (PSTs) levels, which can cause Paralytic Shellfish Poisoning (PSP).

KANA Environmental Coordinator Andie Wall explains why this is an important issue for Kodiak residents: “Many individuals—especially Alaska Native peoples in coastal communities—rely on subsistence resources such as shellfish. As the ocean ecosystems change, the frequency and intensity of harmful algal blooms is increasing.”

The program—funded through the Environmental Protection Agency (EPA) Indian General Assistance Program and the Bureau of Indian Affairs Tribal Resilience Program—is working to provide valuable information Island-wide. Through continuous monitoring of harmful algal blooms and the testing of shellfish saxitoxin levels, the project helps address environmental trends that pose a threat to human health and to mammals utilized as subsistence resources. Project data will help create public advisories for shellfish harvesting at sampled locations. Data will also be uploaded to the Southeast Alaska Tribal Ocean Research (SEATOR) database and linked to the Alaska Harmful Algal Bloom Network website where harvesters can view the most recent toxin and phytoplankton data.

Since beginning fieldwork in March 2019, the presence of all three harmful algal genus types has been confirmed:
Alexandrium—associated with paralytic shellfish poisoning (PSP)
Dinophysis—associated with diarrhetic shellfish poisoning (DSP)
Pseudo-nitzschia—associated with amnesic shellfish poisoning (ASP)
In large quantities, each algal genus poses a threat to human health. This project focuses on the abundance of Alexandrium in the water and the PSP toxin, saxitoxin, in shellfish tissue. PSP is caused by eating shellfish contaminated with saxitoxin. PSP toxins can be found in shellfish (such as mussels, cockles, clams, scallops, oysters, crabs, and lobsters) that usually live in the colder coastal waters near the Pacific states and New England.

Saxitoxins can affect the nervous system. Symptoms usually begin within two hours of eating contaminated shellfish, but can start anywhere from 15 minutes to 10 hours after the meal.
Symptoms can include the following:
• Numbness or tingling of the face, arms, and legs
• Headache
• Dizziness
• Nausea
• Loss of coordination
• A floating sensation
• Muscle paralysis and respiratory failure can occur in severe cases

PSP toxins cannot be removed by cooking, freezing, or soaking shellfish. Crab, because they feed on shellfish, can also become toxic. Even if the crab meat is safe, toxins tend to accumulate in crab gut and "butter" (the white-yellow fat inside the back of the shell). Clean crab thoroughly and avoid eating the crab butter and guts. If you feel any symptoms after eating untested shellfish call 911 or go to your local clinic immediately.
KANA is collaborating with local and state entities to publish community advisories when levels are above the regulatory limit, especially when they reach highly elevated levels.
“Please know that this monitoring project is for development of regional baseline data to discover environmental trends of these harmful species,” says Andie Wall, KANA Environmental Coordinator. “Traditional knowledge is being challenged as we are seeing temperatures rise and ocean chemistry change. PSP levels have been detected at concerning levels in months containing ‘r’. The only way to know the levels of toxins within shellfish is through testing. KANA offers a free Harvest and Hold Program for substance harvest to test their shellfish. Contact us if you would like to test your harvest before consuming, have harvesting strategies you would like to share or are interested in volunteering.”

Please remember, commercially harvested shellfish is regulated and safe for consumption.

Phytoplankton updates and shellfish toxicity levels are public data and can be found at seator.org/data or by contacting KANA Environmental Coordinator Andie Wall at 907.486.1313 or andie.wall@kodiakhealthcare.org.