CHIMACUM – Gibbs Lake has been closed because of a high concentration of toxic blue-green algae found in its waters.
It’s the first time that Jefferson County environmental health officials remember the county lake near Chimacum being closed because of toxic bacteria.
At the same time, the most recent sample of water from Anderson Lake – in which weekly tests have found extremely high concentrations of toxic bacteria since it was closed on June 8 – shows no sign of toxic bacteria.
However, the 70-acre lake, which is eight miles south of Port Townsend in the state park of the same name, remains closed.
Jefferson County Public Works, which oversees county Parks and Recreation that runs the Gibbs Lake County Park, announced Thursday that the lake was closed because the most recent water sample found anatoxin, a powerful neurotoxin, at 5 parts per billion.
County Environmental Health recommends that lakes be closed when the toxin level reaches 1 part per billion.
“The park technically is not closed, but the lake is closed,” meaning that swimming, fishing and other lake-related recreations are prohibited, said Frank Gifford, director of Jefferson County Public Works.
The park around the lake has trails and a ropes course, which will remain open, Gifford said.
Officials have said they do not know the cause of either the blue-green algae or why it sometimes produces toxic bacteria that can sicken people and animals if it is consumed.
Anderson was the first Jefferson County lake to have bene found to contain algae and toxins from the algae.
It was closed last summer, was reopened briefly, and then closed again this year.
Algae has this year been found in both Lake Leland and Gibbs.
Washington State Parks and Recreation officials plan to enter into a contract with county Environmental Health to test Anderson, Gibbs and Leland over a period of a year to gather data to help determine the cause of the toxic algae in the lakes.
At the moment, there are many more questions than answers as to the cause, said Mike McNickle, director of Jefferson County Environmental Health.
Once a cause has been determined, Environmental Health officials can begin to combat the problem.
“We want to make science-based decisions,” McNickle said.