Anderson Lake remains closed to all water recreation, including fishing, after test results received Friday show the amount of anatoxin-a, a powerful neurotoxin, has more than doubled since the prior week.
The latest test results showed Anderson Lake contained 19.9 micrograms per liter of the algae-created toxin, said Greg Thomason, Jefferson County environmental health specialist, Friday, when he received test results of samples taken Monday.
Anatoxin-a is a quick-acting poison made by blue-green algae. It can be fatal for both people and animals if ingested.
Results received the week before show lake water had 7.93 micrograms per liter.
The safe level is 1 microgram per liter.
Results on June 24 showed 1,112 micrograms per liter of anatoxin-a, the highest level since 2008, when the lake set a world record — still unbroken — of 172,640 micrograms per liter.
Although no one should get in the water or fish in the 70-acre lake between Chimacum and Port Hadlock, the 410-acre Anderson Lake State Park surrounding it remains open for hiking, horseback riding, biking — all recreation not related to the lake.
Other lakes tested in East Jefferson County — Leland, Gibbs and Silent lakes — are below detectable levels for anatoxin-a.
All lakes tested — including Anderson — are below the danger level for microcystin, another algae-produced toxin that can damage the liver.
Anderson Lake had .07 micrograms of microcystin, compared to 0.12 micrograms the week earlier.
The concentration was 6.5 micrograms per liter on June 24.
The safe limit for microcystin, a slower-acting toxin than anatoxin-a, is 6 micrograms per liter, Thomason said.
A warning sign remains posted at Lake Leland, while caution signs are at Gibbs Lake south of Port Townsend and Silent Lake on the Toandos Peninsula.
It’s safe to eat properly-cleaned fish from Leland, Gibbs and Silent lakes, but no one should swim in the lakes or drink the water.
Sandy Shore Lake south of Port Ludlow near state Highway 104 remains clear, Thomason said.
Anyone who observes an algae bloom at a Jefferson County lake is urged to phone 360-385-9444 and inform the public health department, which posts information about lake quality 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 algae blooms.
Algae blooms in Clallam County lakes should be reported to the 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@peninsula
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