ABSTRACT

Viewed from space, it is clear why planet would be better named “Ocean” than “Earth.” More than 70% of the planet’s surface is covered by interconnected bodies of water. Life originated in the oceans about 3.5 billion years ago and microbes were the only form of life for two-thirds of the planet’s existence. Ever since a detailed study of the microbial world began in the late nineteenth century, scientists have asked questions about the diversity of microbial life in the sea, its role in ocean processes, its interactions with other marine life, and its importance to humans. Defining the terms “microbiology” and “microorganism” is surprisingly difficult! Microbiology is the study of very small organisms that are too small to be seen clearly with the naked eye, but most microbiologists are concerned with the activities or molecular properties of microbial communities rather than viewing individual cells with a microscope.