Toxins in Anderson Lake have nearly tripled, said Jefferson County environmental health specialist Greg Thomason after tests of samples taken last week were received Friday.
“The lake stays closed, of course,” he said. “It’s getting worse.”
Anderson Lake was closed to fishing, swimming and any kind of recreation June 10 after samples taken June 6 contained 2.67 micrograms per liter of anatoxin-a, a powerful neurotoxin.
Test results of samples taken June 13 showed concentrations of 7.37 micrograms per liter of the algae-produced toxin, which can cause illness or even death in people and animals.
The recreational limit is 1 microgram per liter.
Aside from the lake, the 410-acre park between Chimacum and Port Hadlock is open.
Hiking, horseback riding and biking — all recreation not related to the 70-acre lake — are permitted in Anderson Lake State Park.
Leland, Gibbs, Sandy Shore and Silent Lake are still open, though the cautions were upgraded last week for Lake Leland.
The “caution” sign that had been at the lake was replaced with a “warning” sign, Thomason said.
While tests show that the level of anatoxin-a is still well below the safe level, the amount is increasing, Thomason said.
The latest sample found 0.17 micrograms per liter of the toxin. The week before, the level was 0.04.
“The [algae] bloom is getting really heavy, and there are two toxin-producing algae in the lake, so we put a warning sign up,” Thomason said.
Fish that have been cleaned with the guts discarded can be eaten from lakes posted with either “caution” or “warning” signs.
The difference is that a “caution” sign notes that toxic algae may be present, and that swimmers should avoid scums, while the “warning” sign says toxic algae are present and warns against any swimming at all.
In both cases, lake water should not be consumed.
Gibbs Lake has a “caution” sign posted because it has a slight algae bloom made up of three types of algae known to produce toxins at times.
At present, however, the algae is not producing toxins, Thomason said.
“It’s OK,” he said.
Tests of samples find no detectable amount of either anatoxin-a or the other algae toxin historically found in East Jefferson County lakes, microcystin, which can damage the liver.
Microcystin has not been detected this season in the county’s lakes.
Sandy Shore Lake also tests below detectable levels for algae toxin. The lake is considered clear for all recreation.
The lake has an algae bloom, but there are no toxin-producing algae in it, Thomason said.
“An innocuous type of algae is producing the bloom,” he said.
Silent Lake
No sample was taken from Silent Lake last week, but it will be tested next week.
Two weeks ago, the lake on the Toandos Peninsula was found to be clear of toxins, but it contained algae that could produce toxins, earning it a “caution” sign on its shore.
The algae in Silent Lake “could start producing toxins any minute,” Thomason said.
“You want to assume the worst. If you have a dog, keep it from drinking the water.”
Thomason said fish caught in the lake could be eaten if cleaned properly, but he advised against swimming in it or drinking from it.
Anatoxin-a can cause convulsions and even death by respiratory paralysis.
Anderson Lake has been plagued with summertime closures because of high concentrations of toxins since Memorial Day 2006, when two dogs died after drinking lake water with a heavy concentration of anatoxin-a.
Anyone who observes an algae bloom at a lake is urged to phone the Jefferson County Public Health Department at 360-385-9444.
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 do not test for toxins. Instead, they 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.
