Earth: The Nature of Our Planet – Episode 03: Water

It's ironic that we call our planet 'Earth', when two thirds of its surface are covered by water! The oceans, with their fluctuating water temperatures and global currents, also act as a driving force for local weather phenomena and global climate change. In addition, they provide an immense habitat for a countless variety of species. Some of the most important are microscopically small plants and bacteria. Under the right environmental conditions, they can be seen from space in one of nature's most mysterious spectacles, the algal bloom, a sudden mass reproduction of phytoplankton that changes the color of vast bodies of water into a creeping, luminescent, blue-green expanse. A wonderful vision, but as is so often the case in nature – what is good for some is deadly to others.