This study aims at reconstructing the Barents Sea marine ecosystem before the exploitation by man. This reconstruction will be made by using the existing archival resources on catch statistics from the 17th to 19th centuries in the Netherlands, Germany, Denmark and the United Kingdom, in combination with the present knowledge an animal behaviour and food web structure. Fieldwork is planned in two former hunting areas in Spitsbergen: the Smeerenburgfjord and the Storfjord to study both the structure of the recent marine ecosystem and the composition, size and dating of the recent bird rookeries. This information in combination with the historical data will be used to reconstruct the original ecosystem.