I hadn't until today, but had heard of a few dogs dying after swimming in water contaminated by it. Here's a pic of it and another of the same lake where it hasn't spread to yet.
Algae blooms form when the water is contaminated. Caused by pollution, e.g., from runoff travelling through farms and parking lots, etc., changing the PH, temperature, oxygen levels, etc., of the water. Clear-cutting around bodies of water will also affect the temperature, further degrading water quality. Looks like there's plenty of shade there, though. I am assuming the water levels are lower than average.
@Vivaci like all Algae it requires heat; moisture and the right 'nutrients' in the lake. green. Blue. Brown or Red depending on what the life in the water is.
@Graciebaby you have misunderstood this post. It's blue algae that has occured in various waterways in the UK in the past few weeks that the environmental agencies are aware of, hence putting up warning signs.
