Abstract
The general objective of this proposal is to evaluate the ecological significance of marine benthic scavenger communities and of the large food fall mediated vertical flux by investigating feeding ecology and physiology of representative species of the Ant arctic shelf scavenger guild. This shelf assemblage will be used as a deep sea-like model.A combination of up-to-date tracers techniques will be used to identify the origin of scavenger alimentation: The trophic level of the different scavenger species wit hin the food web will be determined by carbon and nitrogen stable isotopic ratios. The trophic relationships to other taxa will be investigated by analysing the lipid composition and the fatty acid signatures of scavengers and their potential prey taxa. As the metabolic rate is a proxy of overall energy expenditure of an organism, and hence is one possible way of estimating energy flow through the individual organism, scavenger respiration and excretion measurements will be combined with existing informatio n on peracarid energy budgets to etablish a model that can predict daily consumption. The results obtained within the project together with qualitative and quantitative information on scavenger associations from the literature will be integrated in a balan ced model of scavenger assemblage trophic links and energy flows. This model will show how significant the share of scavengers is in overall benthic energy flow, and how sensitive the system may be to changes(climatic, human-induced) in food supply.
Europe