The Lake Ontario Life Support System

Abstract

Primary productivity provides most of the energy to support aquatic food chains. The rate is not only influenced by available solar radiation but also by temperature, availability of phosphorus, and the influence of physical mixing processes. The special features of Lake Ontario such as changes in phosphorus concentration, calcium carbonate precipitation, and silica deficiency on primary productivity, concentration of particulate carbon, and chlorophyll are discussed. Our lack of understanding of food chain and nutrient regeneration processes is illustrated through our failure to balance carbon production with losses through zooplankton grazing and sedimentation. It was demonstrated, however, that bacteria are not responsible for nutrient regeneration through "mineralization" but nutrients are effectively recycled in the water column at the second and third trophic levels.