The Trophic Ecology of Marine Birds and their Influence on Carbon Flow in the North Water Polynya

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This project is a component of the international team of scientists that have been assembled to investigate the North Water polynya (NOW) ecosystem. The proposed study will test the hypothesis that spatial heterogeneity in the species composition of seabirds breeding in the vicinity of the NOW ecosystem is determined by spatial heterogeneity in physical mechanisms that structure NOW. The proposed research is designed to determine the influence of marine birds on the fate of particulate carbon in this High Arctic polynya. Three questions will be addressed: (1) What is the spatial heterogeneity in the distribtuion of foraging seabird species and prey use within the polynya and is this variability related to water masses or other hydrographic features? (2) What is the carbon flux to birds and what are the trophic pathways (food webs) on which the birds depend? (3) Is there seasonal variation in the trophic role of birds and are these the result of changes in the food webs used, or the size classes and species of prey available? To answer these questions, the species composition, abundance, distribution, and diets of marine birds foraging in the NOW will be quantified. These data will be used in conjunction with published models of energy consumption as function of body mas to calculate the daily and annual consumption of energy, prey, and carbon by marine birds in the NOW. Additional data on hydrography and prey fields, which will aid in addressing questions concerning the spatial organization of physical and biological processes in the NOW, will be available from other participating scientists.