The Gippsland Lakes are a chain of lakes in eastern Victoria, Australia. A combination of fire and floods changed the conditions of the water and led to the proliferation of Synechococcus, a photosynthetic cyanobacteria.
BUT... the most interesting thing about these bacteria is that they are bioluminescent, or "glow" when there is any movement. This means that this bacteria will light up when there is a wave or ripple in the water, and wherever people played in the water. Read more about bioluminescence here.
Here are some spectacular pictures of these lakes. You can also see more here.
This is a picture of a rock skipping across the water.