Algae in Lake Erie has been very common the past few decades due to run-off from farms and ditches in northern Ohio/Southern Michigan. While not as vibrant as previous years, the algae and sediments in the lake are visible from space. This image was taken over the weekend. Notice the darker shades of blue on the deeper eastern basin of Lake Erie.
Another, even more amazing shot is of the wildfire that is raging in Yellowstone National Park. The smoke from this fire is being driven north by winds in the atmosphere. It is rare that a wildfire is so easily seen from space.