from Amy Duncan
Tuesday (June 21, 2011), Green Lake resident Mary Griffin spotted an algae scum on the east side of the lake, near the Green Lake Community Center.
The King County Department of Natural Resources and Parks (DNR) took a sample of the algae the next day. Sally Abella of King County DNR identified the predominant bacteria as three cyanobacteria species, including Microcystis and Anabaena, both of which can produce toxins. Preliminary chemical analysis by Washington Department of Ecology was completed Friday afternoon, and indicated 1.8 ug/L microcystis (a liver toxin), significantly less than the state recreational guideline of 6 ug/L.
“This does not seem to indicate an acute health or safety risk at this time,” Abella said. “However, because the algae were somewhat dispersed by the time we investigated, it is quite possible that the state threshold could have been exceeded if a true scum had been sampled.”
Abella has put out a call for volunteers who walk around Green Lake frequently: “Does anyone walk around the lake frequently? If so, could you carry a pint-sized jar or container with you (clean glass) to be able to scoop up a sample if you see a distinct scum? We would need the location as closely as you can describe it and the date/time of the sample. Of course, a picture of the site is worth gold! If you do take a sample, refrigerate it ASAP and email me so we can coordinate a toxicity test with Dept of Ecology and the King County Environmental Lab.”