Deadly Algae Bloom Contaminates Shellfish in Alaska

Scientists warn of deadly shellfish in part of Alaska

ANCHORAGE, Alaska (Reuters) - Public health officials warned Alaskans to avoid eating shellfish they harvest from the southeastern tip of the state after high concentrations of a poison than can kill humans was found.

State officials said scientists monitoring algae blooms near Ketchikan discovered some of the world's highest-ever recorded levels of toxins that cause paralytic shellfish poisoning -- a potentially fatal ailment that can paralyze vital organs.

The most poisonous shellfish discovered were baby mussels at a dock in Ketchikan with toxin levels of more than 30,000 micrograms per hundred grams of shellfish meat. This is well over the 80-microgram level considered toxic, the Alaska Department of Health and Social Services has warned.

Those levels are so high that a single mussel could kill several people, scientists at the University of Alaska Southeast said in a statement on Thursday.

Paralytic shellfish poisoning is caused by a suite of toxins produced by certain dinoflagellates, a major group of phytoplankton.  The toxins accumulate in certain shellfish (clams and mussels are particularly notorious), where they are available to poison animals or humans who consume the shellfish.  These have given rise to superstitions about not eating shellfish in months without "R"s, because of the possibility of poisoning.  While this may be good advice for freshness reasons (months without Rs are warm months), toxic shellfish poisoning of various types can and does occur in the cooler months with Rs.  States with known shellfish poisoning problems monitor shellfish for toxins routinely, and post those results publicly.  If you wish to consume wild caught shellfish, it would be wise to check the current state of advisories.

We in Chesapeake Bay are fortunate in that, despite all our other water quality issues, we do not, as of yet, have any known problems with shellfish poisoning.  While several of the algae known to cause such poisoning have been found in the bay, no known out breaks of shellfish poisoning have occurred.