In episode 63 of MicrobeWorld Video, Dr. Stan Maloy talks with Forest Rohwer Ph.D., Professor of Biology, San Diego State University, about his research on the microbes of the ocean, coral reefs and the human lung. This episode was filmed at the American Association for the Advancement of Science Meeting in Vancouver, Canada on February 18th, 2012. Viruses make up a large portion of the world's oceans, with over ten million per milliliter of seawater. Rohwer's interest in better understanding these viruses led him to becoming an expert in marine virology and a founder of the field of viral metagenomics. Forest discovered that these viruses are very good at controlling the number and type of bacteria in the ocean and through the process of gene transfer possess the potential to change marine bacteria into human pathogens. Among Forest's other interests are coral reefs. He has studied the link between humans inhabiting the land around coral reefs and the decaying health of the corresponding coral. Forest also studies cystic fibrosis, a disease of the human lung, which mimics what he sees going on with the health of coral reefs. Rohwer explains how his work across many different scientific disciplines has helped his research interests broaden while leading to new discoveries unlikely to have been made without the knowledge and tools of other scientific fields.