Monday, September 19, 2011

Algae toxin levels unsafe in Gibbs Lake, Washington - 19th Sept 2011

The level of a slow-acting liver toxin created by blue-green algae is now over the safety threshold at Gibbs Lake south of Port Townsend, preliminary results of the most recent lake sample tests show.

“Toxin levels have been creeping up at Gibbs Lake and [it] is at a ‘warning’ status, which means we don’t recommend that people swim there or have contact with the water right now,” said Mike Dawson, Jefferson County environmental health specialist.

“Microcystin is rising and is over the recreational guideline, it appears,” he said.

Preliminary results show 6.8 micrograms per liter of microcystin in Gibbs Lake.

The recreational safety threshold is 6 micrograms per liter.

Final results of tests of water samples taken last Monday were not available Friday, Dawson stressed, saying he had only preliminary results from King County Environmental Labs, and that the numbers might change when they are finalized.

Microcystin can damage the liver after longtime ingestion.

The posted status of lakes in East Jefferson County did not change last week after initial test results were received.

Toxin levels at Anderson Lake — historically the worst for high levels of anatoxin-a, a fast-acting nerve poison that can be fatal — remain low, Dawson said, and no bloom is visible on it now. Read More