Recalled Maine Shellfish Tainted With Dangerous Neurotoxin, May Cause Amnesia In Humans

A controversy sparked recently when an unusual bloom of toxic algae closed a third of Maine's coastline to clam and mussel harvesting and triggered a widespread shellfish recall. Other shellfish were also recalled after samples tested positive for high levels of a dangerous neurotoxin.               

According to Health, the recall notice was issued by the Maine Department of Marine Resources and was applied to applies to mussels and mahogany quahogs (another name for clams) that were harvested or wet-stored in the Jonesport area between September 25 and September 30; as well as clams harvested between Cranberry Point in the town of Corea to Cow Point in Roque Bluffs between September 28 and September 30.

The Portland Press Herald also reported that the samples tested contained a dangerous amount of domoic acid. Shellfish tainted with domoic acid can cause Amnesic Shellfish Poisoning (ASP) in human, which may later lead to neurological symptoms such as brain damage, disorientation, short-term memory loss, seizures, and possibly death. An ASP outbreak in Prince Edward Island, Canada, in 1987 killed three people and sickened more than 100. "It's a serious issue, it requires attention," said Sandra Shumway, a shellfish expert at the University of Connecticut. "If it is showing up in those high numbers, I'd be worried. It is a very nasty toxin."

Fortunately, Jeff Nichols, a spokesperson for the Department of Marine Resources, told the Herald that no cases of illness have been reported. Fox News reported that the phytoplankton that produces domoic acid have been off the coast of Maine for several years. When the shellfish ingest the phytoplankton, the toxin can pile up in their systems. However, this is the first time for shellfishes in Maine to test positive for harmful levels of the toxin.

Meanwhile, the state regularly tests shellfish at 80 monitoring sites and updates its closure maps. At present, Nichols said that mussels, carnivorous snails, and surf clams are closed from Deer Isle to the Canadian border. Other clams are also closed from Bar Harbor to the border, and European oysters are closed from Deer Isle to Machiasport.

Reports said that in order for an area to be opened, there should be at least two clean shellfish meat samples, less than 20 parts per million, recorded seven days apart. "There is no set timeline for this," Nichols said. "We just continue to rigorously monitor the coast. We don't know how long this is going to last."