A few blobs of algae float near the dock, but those are the harmless filamentous green variety, not the kind Erickson is concerned about. \u201cIt can look gross and smell gross, but that\u2019s not the kind that is going to produce the toxins,\u201d she said. Erickson is looking for blue-green algae, a toxic algae<\/a> that \u2014 in high amounts \u2014 can sicken humans and kill animals.<\/p>\n Water scientists call blue-green algae an \u201cemerging contaminant.\u201d They don\u2019t know too much about it yet, other than that it thrives in warm, stagnant water and that Colorado water quality scientists seem to get more calls every year about lakes with green slime or a turquoise film that looks like paint psreading across the surface.<\/p>\n So far this summer, biologists from the state health department and Colorado Parks and Wildlife have detected blue-green algae blooms at Cherry Creek Reservoir in Denver, Prospect Lake in Colorado Springs, Barr Lake near Brighton and Steamboat Lake. The warmer the lakes get, and the more nutrients available to feed the algae, the more prone they are to toxic algae blooms. August and September are typically the worst months.<\/p>\n