Warm weather combined with a large algae bloom in Southeast Alaska has scientists advising extra caution to recreational shellfish harvesters.
Scientists have identified unsafe levels of Dinophysis algae, which produces diarrhetic shellfish poisoning, in samples from around Ketchikan. DSP can cause diarrhea.
Water samples from around Etolin Island show increasing levels of Alexandrium algae, which produces paralytic shellfish poisoning. Tests also show a slight increase in levels on the west coast of Prince of Wales Island, and extremely high levels around Juneau.
Early signs of paralytic shellfish poisoning include tingling of the lips and tongue. Symptoms can progress to tingling of fingers and toes, then loss of control of arms and legs, followed by difficulty breathing. Death can result in as little as two hours.
All locally harvested shellfish — including clams, mussels, oysters, geoducks and scallops — can contain paralytic shellfish poison. Crabmeat is not known to contain the PSP toxin, but crab guts can contain unsafe levels of toxin and should be discarded.
Toxins can be present in large amounts even if the water looks clear. Also, the toxin can remain in shellfish long after the algae bloom is over. PSP cannot be cooked, cleaned or frozen out of shellfish. Commercially grown shellfish is tested and considered safe.
Suspected cases of PSP should be reported to the Section of Epidemiology by health care providers at 907-269-8000 during work hours or 800-478-0084 after hours.