Toxin levels remained low in Lake Anderson and other East Jefferson County lakes in samples taken last week.
Lake Anderson, Lake Leland and Gibbs Lake all remain open to fishing.
But yellow caution signs sprouted on the shores of those lakes last week.
“The only reason we have the caution signs up is that for the first time this season, we’re seeing some toxic algae species showing up” in water samples, said Gary Thomason, Jefferson County environmental health specialist, by cellphone as he planted the signs at the lakes Friday.
“None of the three lakes have any [algae] blooms, which is great,” he said. “The water is clear.
“Go for it,” he told fishermen.
Toxins created by blue-green algae have especially plagued Lake Anderson, a popular 70-acre trout fishing hole between Chimacum and Port Hadlock, since May 2006, when two dogs died after drinking water tainted with anatoxin, a quick-acting neurotoxin, and the lake was closed.
In April 2010, Anderson Lake was opened for fishing for the first time since 2008 but was closed three weeks later when toxin levels shot up as the weather warmed and encouraged the algae growth.
In 2008, lake samples had the largest concentration of toxins measured in Western Washington when samples tested at a level of 170 micrograms of toxins per liter in June 2008 reading.
A dangerous level of toxin is one microgram per liter, environmental health officials have said.
Anderson Lake opened April 30.
“At this time last year, we had a big bloom in Anderson,” Thomason said, attributing the slow growth of algae in the lake to cool, rainy weather.
“As we get sunnier, warmer weather, it will probably change,” he said.
Toxins found in Jefferson County lakes in the past have been the neurotoxin anatoxin and microcystin, which can cause liver failure.
Test results of samples taken Monday found no detectable level of anatoxin in Gibbs Lake. It was present but barely measurable in Anderson and Leland lakes, Thomason said.
Mycrocytin was below detectable levels, he said.
Although the presence of the algae doesn’t mean the water is poisoned, the fact that it wasn’t detected until last week is cause for caution, Thomason said.
Caution signs say toxic algae may be present and advise lake users to refrain from drinking lake water and to clean fish well, discarding the guts.
Caution notations for Anderson, Leland and Gibbs lakes went up on the environmental health website at http://tinyurl.com/6z64ofy last week. Sandy Shores Lake remained clear of algae.
The site is updated weekly after samples collected each Monday are tested at King County Environmental labs.
Testing will continue throughout the summer.
Jefferson County Public Health has been collecting and submitting water-quality and algae samples from Lake Leland, Anderson Lake and Gibbs Lake since 2006.
For more information, visit the environmental health website. Phone direct questions or comments to the department at 360-385-9444.
No toxic blue-green algae has been reported in Clallam County, where health officers visually monitor lakes for signs of algae bloom.
Algae blooms in Clallam County lakes should be reported to the Clallam County Department of Health and Human Services’ environmental health division at 360-417-2258.
