Legionaire’s pneumonia outbreak in 1992 at a water-cooling tower in West Yorkshire of Bradford England brought the discovery of a new microorganism. An officer name Timothy Rowbotham was mandated at the site of pneumonia outbreak at the time for the Public Health Service in Britain. He was investigating the source of pneumonia, but instead, discovered the Mimivirus. The water cooling tower brought to attention of where the Mimivirus might come from. A study performed by Claverie et al. 2009 revealed from an aquatic environmental DNA sample, that there as quite a surprising number of large DNA viruses related to the Mimivirus in the aquatic environment (Ghedin, 2005 & Monier, 2008). These large DNA related Mimiviruses appears to be important to the ecology of species micro- and pico- plankton in oceans and fresh water. There are some indirect evidence of Mimivirus correlations to corals and sponges as well (Claverie, 2009). Following this line of thought, Claverie believed that some Mimiviridae evolved to infect aquatic organisms and depended on phagocytosis as the food source. Further investigations on environmental relevance are still needed.