CHIMACUM — Laboratory tests of blue-green algae from Anderson Lake showed Tuesday that high concentrations of toxicity did exist in the state park lake that Jefferson County health officials shut down Saturday.
The algae poisoned three pet dogs which drank from the lake, resulting in the deaths of two.
Anderson Lake State Park remains closed today as a result of the poisonings — and until the deadly algae dissipates in the 70-acre lake.
The Jefferson County Public Health Department on Tuesday afternoon received the results from a water management laboratory in Tacoma of samples taken from the lake on Monday.
“There were 1.5 million cells of blue-green algae per milliliter, which is a pretty high concentration,” said Jefferson County Environmental Health Director Mike McNickle.
“We had all three major species of the toxic algae.”
McNickle said the results of the tests give clear certainty that the cause of the dog deaths and near-death were caused by ingesting the algae.
The most common species of toxic blue-green algae is called anabaena, which showed up in 76 percent of the samples.
Fifteen percent was aphanizomenon, and 9 percent was microcystis, according to the test results.
All three are toxic.