This study concerns the general question of how food material is transferred from plants (which initially manufacture the food), to herbivores and carnivores in the sea. Recently, the accepted view of this process has undergone a healthy reexamination. The simple notion that the food material passes mainly to relatively large grazers and then to harvestable organisms such as fish has been supplanted by the recognition that much of the plant material produced is consumed by a variety of microscopic organisms in what has been termed the microbial loop. This study will employ several well conceived laboratory studies to analyze the role of certain widespread marine micro- organisms known as ciliates in the flow of food energy in this biological "loop". The results will directly advance our understanding of marine food webs.
