This book provides essential information regarding the dynamics and rate processes of nitrogenous compounds in the sea. Topics discussed include characteristics and behavior of nitrogen at the atomic, molecular, and isotopic levels; elemental rate processes and physico-chemical and biological factors; the dynamics of nitrogen in several representative marine ecosystems; and current progress in isotope marine biogeochemistry. The book emphasizes the distribution and variation of nitrogen isotopes, which can provide a novel approach to understanding nitrogen metabolisms occurring in marine ecosystems. Nitrogen in the Sea: Forms, Abundances, and Rate Processes should be considered an indispensable reference tool for researchers and post-graduate students interested in the nitrogen cycle in aquatic ecosystems