PORT TOWNSEND — The most recent results of testing show no change in the dangers associated with toxic blue-green algae in Jefferson County lakes — but that doesn’t reflect the possible effect of last week’s heat wave on the warmth- and light-loving organisms.
Red warning signs remain at Anderson and Leland lakes, which are closed to recreational use, while a yellow warning sign at Gibbs Lake permits recreational use as long as small children and pets are kept out of the water, no one drinks the water and fish are well-cleaned before they are eaten.
“I’m quite glad that things don’t seem to be getting worse, that we seem to be maintaining the status quo, as we’re entering the summer,” said Neil Harrington, county water quality programs manager, Friday afternoon.
It could be a different story next week.
Samples of the lakes are taken each Monday. Test results from King County Environmental Labs generally are received by Friday of that week. So the effect of last week’s heat wave, in which temperatures soared into the 90s and higher, will not be known until Friday.
“Certainly, the heat wave has created conditions in the lakes that would make algae reproduce more rapidly,” Harrington said.
‘Stratified’
Harrington said lake water becomes “stratified” during high temperatures, meaning that a warm upper layer does not mix with a colder layer underneath.
“It would probably help algae growth, because the cells that are higher up will stay in high light conditions,” he said.
Gibbs Lake in Chimacum was upgraded July 17 after testing showed that levels of algae had dropped.
It remains open to recreational use, with the following caveats:
• Do not drink lake water. Boiling, filtering and treating will not destroy the toxin.
• Keep small children and pets out of the water. Smaller bodies are more susceptible to the toxins.
• Avoid visible scums, which can have more than 1,000 times more algae than water that appears clear,
• Clean fish well, discarding organs and skin. The toxins can concentrate in skin and organs, especially the liver.
• People with liver disease, such as chronic hepatitis, should exercise additional caution.
Recreation ban
Recreation remains banned in both Anderson Lake, which is in a state park between Port Hadlock and Chimacum, and Lake Leland, north of Quilcene and south of U.S. Highway 101. Recreation is permitted in the state park around Anderson Lake.
A red warning sign means the lakes have high levels of potentially toxic blue-green algae — more than 100,000 cells per milliliter of water — and that no one should drink the water, swim in the lake or eat fish from it.
A “caution” status means the lake has moderate levels of potentially toxic blue-green algae species, between 30,000 and 100,000 cells per milliliter of water.
Sandy Shore Lake, from which the county is also taking water samples for weekly lab testing, remains clear and safe for public recreational use. So do Crocker, Teal and Tarboo lakes.
The first time Anderson Lake was closed was in June 2006 after two dogs were killed from ingesting the water, and one nearly died after experiencing a seizure.
It has been closed for periods of time during warmer months since.
This year, the popular trout-fishing lake was closed just before the opening of the season April 25.
Leland was closed in mid-May.
Cyanobacteria, or blue-green algae, are present in most bodies of water and usually are not toxic to humans or animals.
But when the right conditions align — the water is calm, relatively warm and overly rich in phosphates — a chemical commonly found in lawn fertilizers — they can bloom into high concentrations.
The algae can, at times, begin to produce toxins, such as the neurotoxin anatoxin-a, which can cause convulsions and death by respiratory paralysis.
Jefferson County Public Health has been collecting and submitting water quality samples from Lake Leland, Anderson Lake, Sandy Shore and Gibbs Lake to determine what species of algae are present and at what concentration they are present since 2006.
Other local lakes are sampled if they appear to be undergoing a blue-green algae bloom.
The department also collects samples for nutrient analyses and physical data to determine possible causes for these blue-green algae blooms in a study funded by a state Department of Ecology grant.
Jefferson County Public Health maintains an updated database of lake monitoring information at http://tinyurl.com/jeffcolakes.
The department can be reached at 360-385-9400.
Lake samples are not tested in Clallam County, where health officers visually monitor lakes for signs of algae bloom. No cautions or warnings have been issued in Clallam County.
Algae blooms in Clallam County lakes should be reported to Clallam County Department of Health and Human Services environmental health division at 360-417-2258.
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Managing Editor Leah Leach can be reached at 360-417-3531 or leah.leach@peninsuladailynews.com.
