The toxins are low, and the fishing is good for now, but public health officials are wary of the warming weather’s future effect on blue-green algae growth in East Jefferson County lakes.
“There are no changes” seen in the water samples taken from Anderson, Leland and Gibbs lakes last week, said Greg Thomason, Jefferson County environmental health specialist, on Friday.
“The toxins are still very low — about the same as last week — and there’s still no visible bloom,” he said.
All three lakes are posted with yellow caution signs because of minute amounts of algae species that produce toxins showing up in water samples.
“It’s still good to go, good to fish,” Thomason said.
Samples will be taken from all three lakes Monday and sent to King County Environmental labs for testing as they are every week during the summer.
But also, given the onslaught of pleasant weather, Thomason will be alert for algae blooms.
“If it stays warm and sunny, I will be out there checking all three lakes, probably on Thursday, to see if there are any visible blooms,” he said Friday.
‘Anything can happen’
“Anything can happen after three or four days of sunny weather.”
Researchers have noticed that warmer, sunny days tend to aid in the incubation of algae blooms that carry toxins microcystin, which damages the liver, and anatoxin-a, a powerful neurotoxin.
They aren’t sure exactly how weather affects algae growth.
“Is it sunlight, temperature or a mix of the two?” Thomason said.
“It’s really hard to predict.”
Toxins created by blue-green algae were first measured in East Jefferson County in Lake Anderson, a popular 70-acre trout fishing hole between Chimacum and Port Hadlock, after two dogs died after drinking water tainted with anatoxin-a in May 2006.
That discovery prompted the first closure of Lake Anderson because of algae toxins.
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 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.
A dangerous level of toxin is one microgram per liter, environmental health officials have said.
This year, Anderson Lake opened April 30 for the fishing season and has since stayed open largely, Thomason thinks, because of the unseasonable cool, rainy weather.
“As we get sunnier, warmer weather, it will probably change,” he noted earlier this month.
The situation now is that the algae species known to produce toxins have been found in samples from the three lakes.
Although the presence of the algae doesn’t mean the water is poisoned, it is of enough concern to erect the yellow caution signs at the lakes.
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.
Last week, caution signs were changed to add a warning that “algae toxins may be present in fish tissue.”
Fish tissue
The warning stems from research showing that microcystin accumulates in fish tissue — the part that is eaten — as well as in viscera.
The signs direct those who want more information to phone 360-385-9444 — the phone number for Jefferson County Public Health.
Anyone who observes an algae bloom at a lake also is urged to call that phone number.
“We’re counting on the public to call us if they see any visible blooms” at any lake in the county, Thomason said.
“If we get a call saying they have seen a bloom, we’ll be out there checking it right away.”
For more information about lake quality in Jefferson County, visit the environmental health website at http://tinyurl.com/6z64ofy.
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.
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Managing Editor/News Leah Leach can be reached at 360-417-3531 or leah.leach@peninsuladailynews.com.