The analysis of the food web of an algal belt in Kongsfjorden is based on the investigation of 3 transects at Hansneset. The transsects are located in the same place as during a study in 1996-1998 allowing the demonstration of possible alterations in community structure due to global climate changes. Species composition of plants and animals and their biomass had been studied. Samples were taken quantitatively by divers and were further processed in the Marine Lab. Data on basic ecological processes and parameters of the dominant components of the system as biomass, production, respiration and excretion have been measured. Diet analysis of heterotrophs has been done via analysis of stable isotope ratios C and N, and analysis of fatty acids. In a synthesis of the existent data on Kongsfjorden and the additionally gathered new data on the bentho-pelagic system of the habitats on hard bottom, a first model of the food web has been constructed with the “Ecological Network Analysis (ENA)”. ENA gives an analysis of the food web interactions and a characterization of the system in respect of stability, sensitivity to disturbance, with respect to energy flow and material cycling. Since climate warming is changing coastal arctic systems, the changing functioning of these ecosystems is discussed.