1: Microorganisms and the Biological Cycling of Selenium. - 1. Introduction. - 2. Selenium in the Environment. - 3. Microbial Transformations of Selenium. - 4. Biological Cycling of Selenium. - 5. Conclusions and Remarks. - References. - 2: Effects of Environmental Factors and Their Interactions on Phytoplankton Growth. - 1. Introduction. - 2. Nutrients. - 3. Light. - 4. Temperature. - 5. Concluding Remarks. - References. - 3: Factors Limiting Productivity of Freshwater Ecosystems. - 1. A Perspective on Freshwater Ecosystems. - 2. The Concept of Limiting Factors. - 3. Geological Physical Chemical and Biological Characteristics of Freshwater Ecosystems in Relation to Nutrient Limitation. - 4. The CO2 Limitation Question. - 5. Vitamins and Growth Promoting Substances as Limiting Factors. - 6. Microbial Strategies Counteracting Growth Limitations. - 7. Determining Factors Limiting Primary Productivity in Freshwater. - 8. Concluding Remarks. - References. - 4: Biomass and Metabolic Activity of Heterotrophic Marine Bacteria. - 1. Introduction. - 2. Determination of Bacterial Number and Biomass. - 3. Determinations of Bacterial Activity. - 4. Discussion. - References. - 5: Starvation-Survival of Heterotrophs in the Marine Environment. - 1. Introduction. - 2. Background Information. - 3. Organic Matter in Oligotrophic Marine Waters. - 4. Starvation-Survival. - 5. Substrate Capture. - 6. Chemotaxis. - 7. ATP and Energy Charge. - 8. Substrate Uptake. - 9. Conclusions. - References. - 6: Are Solid Surfaces of Ecological Significance to Aquatic Bacteria?. - 1. Introduction. - 2. Characteristics of a Surface. - 3. Conditioning Films. - 4. Adhesion Mechanisms. - 5. Bacterial Nutrition Relative to the Trophic State of Waters. - 6. Ecological Advantages of Attachment. - 7. Succession and Microbial Film Development. - 8. ConcludingRemarks. - References. Language: English