Marine biotoxins that cause paralytic shellfish poisoning (PSP) have been detected at dangerously high levels in shellfish samples collected from north Puget Sound of Washington State.
The so-called “red tide” toxin levels have been as much as 100 times higher than the closure level.
The state Department of Health has closed several areas to recreational shellfish harvest because of these dangerous toxin levels, and conditions have been unchanged since Oct. 13.
All of Whatcom County and all of San Juan County, Deception Pass, Fidalgo Bay, Samish Bay, Sinclair, and Cypress Islands in Skagit County are closed.
The northern part of Whidbey Island, from Keystone Harbor on the west to Strawberry Point on the east including Deception Pass, is also closed to recreational shellfish harvest.
A second bloom has recently been detected in Discovery Bay in Clallam and Jefferson counties, also prompting a shellfish harvest closure. Toxin levels in Discovery Bay are not as high as those found in north Puget Sound, but should also be taken seriously.
Warning signs have been posted at popular shellfish beaches warning people not to harvest from the closed areas. The closure includes clams, oysters, mussels, scallops, geoduck, and other mollusks. Anyone who recently harvested shellfish from these areas should not eat them, and throw them out.
Crab is not included in the closure, but “crab butter” should be discarded. Only the crabmeat should be eaten.
Commercially harvested shellfish currently on the market have been thoroughly tested and are okay to eat.
Eating shellfish contaminated with biotoxins can make people sick. Cooking or freezing does not destroy marine biotoxins and can be life threatening. Symptoms can appear within minutes or hours of eating contaminated shellfish. They usually begin with tingling lips and tongue, moving to the hands and feet, followed by difficulty breathing, and possibly death. Anyone with these symptoms should get medical help right away.
The toxin is produced by naturally occurring algae that tend to be more common during the warmer months of the year. In most cases the algae that contain the toxins cannot be seen, and must be detected through lab testing.
Photo courtesy Washington Department of Fish and Wildlife.