Wow, is the Potomac skanky these days. The dearth of rain has brought the levels down and between the stagnant water and the heat, the algae and underwater growth is flourishing. Here's a little meditation on the underwater growth. Many of these river shots are the product of my morning meditations by the river. Over time I start to notice things externally (as I do internally) that I had not noticed before.
This image is from a pond. Last year about three old trees came down, exposing the pond to sunlight. The result is a permanent cover of algae and growth.