The inspiration for this monograph derived from the realization that human technical capacity has become so great that we can, even without malice, substantially modify and damage the gigantic and remote outer limit of our planet, the stratosphere. Above the atmosphere of our ordinary experience, the stratosphere is a tenuous layer of gas, blocked from rapid exchange with the troposphere, some twenty kilometers above the surface of the earth, seldom reached by humans, and yet a fragile shell which shields life on earth from a band of solar radiation of demonstrable injurious potential. It is immediately obvious that if stratospheric ozone were reduced and consequently the intensity of solar ultraviolet radiation reaching the earth's surface were increased, then human skin cancer, known to be related to solar ultraviolet exposure, would also be increased. But how does one even begin to estimate the impact of changed solar ultraviolet radiation on such a diverse. interacting, and complex ecosystem as the oceans? Studies which I conducted in Iceland focused on this question and were noted to the Marine Sciences Panel of the Scientific Affairs Committee of NATO by Professor Unnsteinn Stefansson, leading to a request to investigate the possibility of organizing a NATO sponsored Advanced Research Institute on this topic.

Inhalt
Atmosphere and Basic Biological Dosimetry.- Preface to Section I.- UV-B Reaching the Surface.- Possible Anthropogenic Influences on Stratospheric Ozone.- Ozone Depletion Calculations.- On the Latitudinal and Seasonal Dependence of Ozone Perturbations.- Middle Ultraviolet Irradiance at the Ocean Surface: Measurements and Models.- The Effect of Perturbation of the Total Ozone Column Due to CFC on the Spectral Distribution of UV Fluxes and the Damaging UV Doses at the Ocean Surface: A Model Study.- Multi-Wavelength Determination of Total Ozone and Ultraviolet Irradiance.- Radiometric Measurements in the UV-B Region of Daylight.- Photobiological Dosimetry of Environmental Ultraviolet Radiation.- Action Spectra.- Some Thoughts on UV Action Spectra.- Action Spectra and Their Role in Solar UV-B Studies.- Action Spectra: Emphasis Mammalian Cells.- Dosage Units for Biologically Effective UV-B: A Recommendation.- Measuring Devices and Dosage Units.- The Sunburn UV Network and its Applicability for Biological Predictions.- Description and Application of a Personal Dosimeter for Measuring Exposure to Natural Ultraviolet Radiation.- Nomograms for Biologically Effective UV.- A Formula for Comparing Annual Damaging Ultraviolet (DUV) Radiation Doses at Tropical and Mid-Latitude Sites.- The Hydrosphere.- Preface to Section II.- Spectral Irradiance Penetration in Natural Waters.- A Method for the Estimation of the Penetration of Biologically Injurious Solar Ultraviolet Radiation into Natural Waters.- Yellow Substance in the Sea.- Note on the Role of Vertical Mixing in Relation to Effects of UV Radiation on the Marine Environment.- Photochemical Transformations Induced by Solar Ultraviolet Radiation in Marine Ecosystems.- Penetration of Solar UV-B into Waters off Iceland.- The Biosphere.-Preface to Section III.- Lethal Effects on Biological Systems Caused by Solar Ultraviolet Light: Molecular Considerations.- DNA Damage of the 5,6-Dihydroxydihydrothymine Type Induced by Solar UV-B in Human Cells.- Mechanisms of Actions of Longwave-UV on Marine Organisms.- Survival of the Brine Shrimp, Artemia Salina, After Exposure to 290-NM Ultraviolet Radiation, with and without Maximum Photoreactivation.- Photoreactivation: Mammalian Cells.- The Amelioration of UV-B Effects on Productivity by Visible Radiation.- Error Prone Repair-Emphasis Weigle Reactivation.- Sensitivity to UV-B Irradiation as Related to Bacterial Life Cycles.- Pigment Dispersion by Light in the Melanophores of the Fiddler Crab.- Yellow Lens Pigment: An Adaptation for Activity in Bright Sunlight.- Photomovement of Aquatic Organisms in Response to Solar UV.- Movement Reactions of Blue-Green Algae in Response to Their Photoenvironment.- Short-Term Responses of Some Planktonic Crustacea Exposed to Enhanced UV-B Radiation.- Review of Literature Concerning the Impact of UV-B Radiation Upon Marine Organisms.- Assessment of Effects of UV Radiation on Marine Fish Larvae.- The Effect of UV-B Irradiation on the Integument of the Marine Flatfish Pleuronectes Platessa L..- Assessment of the Influence of Enhanced UV-B on Marine Primary Productivity.- Modeling Light Loss Versus UV-B Increase for Organisms Which Control Their Vertical Position in the Water Column.- Effects of UV-B Radiation on Thalassiosira Pseudonana: A Preliminary Study.- The Effects of Ultraviolet Irradiation on Photosynthesis by Ruppia Maritima L. (Widgeon Grass).- Effects of UV Radiation on Photosynthesis of Natural Populations of Phytoplankton.- The Effect of High Intensity U.V. Radiation on Benthic Marine Algae.- The Effects of UV-B Irradiation on Higher Plants.- Preliminary Results Regarding the Spectral Efficiency of UV on the Depression of Photosynthesis in Higher Plants.- Possible Errors in Photosynthetic Measurements Arising from the Use of UV-Absorbing Cuvettes: Some Examples in Higher Plants.- Biological Interactions Between Wavelengths in the Solar-UV Range: Implications for the Predictive Value of Action Spectra Measurements.- Does Solar UV Influence the Competitive Relationship in Higher Plants.- A Model to Evaluate the Impact of Cyclically Recurring Hazards on Selected Populations.- Solar UV Radiation as a Selective Force in the Evolution of Terrestrial Plant Life.- Atmospheric Evolution and UV-B Radiation.- Some Considerations on the Ecological and Evolutionary Effects of Solar UV.- The Attenuation of Light by Marine Phytoplankton with Specific Reference to the Absorption of Near-UV Radiation.- Possible Influences of Solar UV Radiation in the Evolution of Marine Zooplankton.- List of Contributors.