What is going on in the lakes when no climate changes are occurring? What is the role of natural changes such as succession in primary producers, food resources, oxygen conditions, intra- and inter-specific competition and changes in benthic and pelagic fish communities? 1) We are using stable isotope analyses on the most common chironomid taxa from West Greenland as well as on their potential food resources. Successful results will allow us to infer down-core changes in food-web structures. 2) We study the relation between fish communities and chironomid (and Chaoborid) assemblages in acidified lakes in southern Sweden. 3) What do we find in sediment cores from the Azores Islands - an Archipelago with relatively stable temperature/climatic history, undisturbed by human until ~600 BP and without freshwater fish in the crater lakes until ~150 BP?