Historical relationships between climate factors and life history of High Arctic freshwater fish; predicting consequences of climate change

Lakes in the High Arctic are characterized by low water temperature, long-term ice cover, low levels of nutrients and low biodiversity. Thus, minor climatic changes may be of great importance to Arctic freshwater fish by influencing gonad development and individual growth rate - two life history parameters strongly affecting production and subsequent year class strength. By using fish otolith-derived water temperature inferences based on otolith thermometry and meteorological data, causal historical relat ionships between climatic variation and life history parameters may be reconstructed. The circumpolar Arctic charr (Salvelinus alpinus) is the only freshwater fish in Svalbard (as in the most of the High Arctic), and include anadromous, freshwater residen t, and landlocked populations. The charr grow up to 35 years, and their otoliths provide a highly suitable tool for growth back-calculations, thus presenting an ideal model for studies on how environmental factors affect life history traits in Arctic fre shwater fish communities. Increased temperatures and changes in precipitation, as consequences of global warming, are predicted to affect both terrestrial and aquatic communities over large areas of the northern hemisphere. Increases in temperature and precipitation are predicted as consequences of global warming, and increases in winter precipitation will come in the form of more snow at very high latitudes, in contrast to more southern areas. The projected changes have the potential to affect Arctic l akes? freeze-up dates, insulation, ice thickness, water temperature, break-up dates, all of which profoundly would affect the ecology of fish. The objective of this proposal is to examine the effect of these factors on the life history of Svalbard Arct ic charr using cutting-edge analytical methods and to use Svalbard Arctic charr as a model organism for predicting the consequences of different climate change scenarios on freshwater ecosystem in the Arctic.