First Paragraph
The last 10–15 years have seen major changes in our views of marine planktonic food webs, primarily from the realization that prokaryotic microorganisms and small eukaryotes are responsible for a significant fraction, often 50% or more, of the primary production and heterotrophic consumption of organic matter in these systems (Williams, 1981: Azam et al., 1983: Stockner and Antia, 1986: Fuhrman, 1992). However, it has only been in the past few years that marine scientists have investigated the roles of viruses in ecological processes. Although this research area is only in its infancy, early results suggest that viruses may be important agents in the mortality of marine microorganisms and in controlling their genetic compositions. This paper will summarize the experiments and measurements that have led to this suggestion as well as the conceptual framework within which they are interpreted.