Recent Marine Environments.- The Effects of Marine Benthos on Physical Properties of Sediments.- The Effects of Macrobenthos on Chemical Properties of Marine Sediment and Overlying Water.- Recent Freshwater Environments.- The Effects of Benthos on Physical Properties of Freshwater Sediments.- Effects of Macrobenthos on the Chemical Diagenesis of Freshwater Sediments.- Ancient Environments.- Geological Significance of Marine Biogenic Sedimentary Structures.- Geological Significance of Aquatic Nonmarine Trace Fossils.- Models.- Mathematical Models of Bioturbation.