Brookmill Park Lake, Britain, when there was a severe algal problem.

The picture shows Brookmill Park Lake again, 11 months later in September 2009. A number of things—stagnant water movement, high temperatures, and/or an influx of nutrient material, such as lawn fertilizers—could have contributed to the explosive growth of algae to form this thick green mat. I'm not sure if odor was a problem at this time, but I'm sure even if no smells were present, the local residents did not sit by this lake for a pleasant family picnic. Well, at least the duck seems to be enjoying having this lake all to himself, unless he is stuck in the gooey mess and can't get out.