Marine bacteria are an essential component of the marine environment.
Surface bacteria appear tobe highly specific and reflect the unique chemical compositions of thehost surface. Recent investigations indicate thatbacterial associations are important adaptations for survival. Bacteriafound in association with other organisms frequently produce metaboliteshypothesized to provide defenses against encroaching pathogens. Incomplex, organic-rich marine sediment communities, competition for substrateand nutritional sources may involve inter specific competition throughthe production of antibiotics. Examples of early research results,which involve estuarine shrimp, bacteria associated with seaweeds and ascidians,and a study of sediment bacterial communities, provide the foundation forthese hypotheses.