Marine microbiology began with the investigations of marine microfouling by L. E. Zobell and his colleagues in the 1930s and 1940s. Their interests focused primarily on the early stages of settlement and growth of microorganisms, primarily bacteria on solid substrates immersed in the sea. The interest in the study of marine microfouling was sporadic from that time until the early 1960s when interest in marine bacteriology began to increase. Since 1970 the research on the broad problems of bioadhesion and specifically the early stages of microfouling has expanded tremendously.

The initial step in marine fouling is the establishment of a complex film. This film, which is composed mainly of bacteria and diatoms plus secreted extracellular materials and debris, is most commonly referred to as the "primary film" but may also be called the "bacterial fouling layer," or "slime layer." The latter name is aptly descriptive since the film ultimately...