PORT TOWNSEND — A high level of a potent nerve toxin has been found in samples of Lake Anderson.
Washington State Parks staff have posted “Danger – Lake Closed” signs at access points to the park alerting visitors of the potential hazards.
Jefferson County Public Health recommends individuals follow Gov. Jay Inslee’s “Stay Home, Stay Healthy” order, and all state parks remain closed through at least May 4, including Anderson Lake State Park.
Anderson Lake was not stocked with trout by the state Department of Fish and Wildlife this year, and recreational fishing is closed.
In a water sample taken on Monday, April 13, laboratory analysis revealed a toxin concentration of 14.8 micrograms per liter of anatoxin-a, which is above the state threshold of 1 microgram per liter.
The lake, which has been plagued for more than a decade with high levels of anatoxin-a, has an early bloom of cyanobacteria, which is also known as blue-green algae.
In time, blue-green algae will begin to make toxins. Scientists do not understand what triggers the poison.
The county health department is in the process of completing an Anderson Lake Management Plan to identify the underlying cause of the recurring highly toxic cyanobacteria blooms, and determine potential strategies for mitigation, officials said.
The project is funded in part through a grant from the state Department of Ecology.
Gibbs Lake and Lake Leland in Jefferson County also are routinely monitored for toxins. Neither has an algae bloom at this time.
To check the status of Jefferson County Lakes and learn more about toxic cyanobacteria monitoring, see tinyurl.com/PDN-LakeStatus or call 360-385-9444.