Front Matter -- General Information on Marine Radioecology and on Risk Assessment -- The Origins of Radionuclides in Marine Environments -- The Fate of Radionuclides in the Marine Environment -- The Fate of Radionuclides in the Marine Biosphere -- Radioactive Contamination of the Marine Environment and Monitoring Programs -- Radiation Doses Received by Marine Organisms -- Effects of Irradiation on Marine Organisms -- Characterization of Radioactive Risk in Marine Organisms.