Due to the discovery of high toxin levels, Pass Lake in Deception Pass State Park is closed until further notice.
Water samples tested this week show high Anatoxin-a levels at over 2500 times the safe level.
Anatoxin-a is a neurotoxin that can be harmful to plants and animals.
Even short-term exposure is a concern, as signs of neurotoxin poisoning appear within 15-20 minutes of ingestion.
Red “danger” signs will be posted at the lake advising the public to keep themselves and their pets out of the lake.
Pass Lake will be continuously monitored until the levels drop below recommended guidelines.