Human activities are changing habitats, the chemistry of the Earth’s atmosphere and water, rate and balance of biogeochemical processes and diversity of life on the earth. This book examines the effects of metal contaminants in natural ecosystems, which are diverse, complex and often unpredictable. Establishing relationships between organism metal exposure, internal dose and associated biological effects is necessary to understand the fate and effects of metals in the environment. Furthermore, the study of marine planktonic protists in the nano-size range (2-20 um) is of great importance as these microorganisms are essential constituents of marine ecosystems and responsible for key trophic processes in the microbial food web. This book presents a comprehensive compilation of the taxonomy of these microorganisms with emphasis on their size range. Current and potential taxonomic tools for the identification of nanophytoplanktonic protists are also outlined. In addition, this book examines sediment records, that can provide much information on the paleoproductivity in past ecosystems, historical records of nutrients supplied and long term potential environmental impacts. Other chapters explore recent advances in sounding technology that use airborne optical techniques to examine seafloor topography, and innovative regional habitat creation programmes developed to plan and manage the delivery of habitat creations, and to protect or enhance the environment.