Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Diatom communities are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality. This book presents topical research data in the study of diatoms, including the role of environmental factors in shaping diatom frustule; marine diatom communities; diatom classification methods; an analysis of the diatom flora of lakes, ponds and streams of the Kuril Islands; the ecological information of diatoms provides information on the reconstruction of palaeo-environments; and the regulatory influences of diatoms on benthic invertebrates.