Optical Properties and Autotrophic Production in Inland Waters in Atlantic Canada With Reference to Research Diving

Solar insolation impinging upon and penetrating the surface of a water body undergoes a variety of changes depending on the physical and chemical characteristics of the water column. Photosynthesis and phototrophic responses of organisms are related to the number of quanta of light of specific frequencies impinging on biochemical receptor systems. Colored waters with high concentrations of dissolved organic carbon (DOC), primarily in the form of humic and fulvic acids, predominate in certain areas of the Atlantic region. These high molecular weight organic compounds strongly influence spectral quantity and quality in waterbodies receiving land drainage. This paper discusses optical properties in clear and colored inland waters and their effects on autotrophic production with reference to problems related to underwater research diving activities.