WASHINGTON — A large algae bloom releasing a dangerous neurotoxin is closing shellfish harvesting on Washington's coast. 

The algae known as Alexandrium produces toxic harmful algal blooms that cause Paralytic Shellfish Poisoning, or PSP, in humans. Alexandrium is more commonly found in Puget Sound, but right now it's overtaking the state's coastal waters. 

"All of this area here that is in red is closed right now to shellfish harvest," explained Stephanie Moore, Research Oceanographer at NOAA's Northwest Fisheries Science Center.

The biotoxin created by the algae causes paralysis of the abdomen and chest when humans consume it in shellfish, Moore said.

"Normally what would be considered safe for humans to eat is 80-micrograms of the toxin per 100-grams of shellfish tissue. What we are seeing right now is values in excess of 1000,” Moore said. "That means that eating just a couple of muscles could land you in the hospital."

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Although no one is totally sure why the algae bloom has grown so big, it may have something to do with warming water off the coast.

"And you can see straight away that it is all red,” Moore said pointing to a map. “Conditions that we are seeing right now are much warmer than normal."

The waters are about 7-degrees warmer than normal, conditions that make it easier for the harmful algae blooms to grow.

The Skagit County Public Health Department announced all of Skagit County is currently closed to shellfish harvesting due to a dangerous amount of the toxin being discovered in local shellfish.

Shellfish harvesting will remain closed until tests show the marine biotoxin is no longer at a level of public health concern. 

You can stay up to date at the Washington State Department of Health Marine Biotoxin website here.

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