As key components of freshwater (lake and river), estuarine and nearshore marine aquatic environments of the circumpolar north, Arctic char and related fishes of the genus Salvelinus are fundamental to the lifestyles and well-being of northerners as the basis for extensive fisheries conducted for household food (i.e., domestic and subsistence), commercial and sport purposes. Chars contribute significantly to household and wage economies, and social and cultural elements of northern life. Chars are also key integrators and indicators of the health of northern aquatic ecosystems, many aspects of which are at significant risk from increased climate variability and change. However, human adaptive responses are hampered by a lack of vital information regarding char thermal ecology, biodiversity and its functional significance in northern ecosystems, mercury and other pollutant interactions, and how these may respond to climate change.

Climate warming is resulting from disruption of the global carbon (C) cycle. The Arctic is already warming significantly and the region governs some critical feedbacks in global change, including release of huge C stores from high-latitude soils, shift in albedo due to changes in vegetation and snow cover, and potential effects on the thermohaline circulation as a result of alterations in river discharge to the Arctic Ocean. However, the links between climate, the C cycle, energy balance, and hydrology are complex and our understanding of them – and their impact on Arctic ecosystems – is poor. ABACUS aims to provide answers to these critical questions.

The Overarching problems to be adressed by the project relates to the impact of globalization, privatization and liberalization. The Arctic regions still in most cases are characterized by economic dependence on centres in the South, which dominate trade patterns and capital movements. Hence, the main research question is related to both positive and negative impacts of the global economy

The polar environments are rapidly changing and leaving a lasting impact on the freshwater and terrestrial ecosystems within them. However the region is so vast and diverse that the knowledge of what drives these changes is limited. This project will assess how terrestrial and freshwater ecosystems and environments have changed in the past and record their current status and biodiversity. IPY provides a timely opportunity for passing on knowledge to new generations of researchers and forming a new and authoritative baseline of environmental characteristics with which to examine future changes. Among the sites to be studied are some first examined during the ICSU-sponsored International Biological Programme, which will allow some assessment of changes over recent decades.

There is increasing recognition that multiple environmental changes are occurring in the northern regions of Europe. Some of these environmental changes, for example climate warming, levels of UV-B radiation, and habitat fragmentation, are projected to continue leading to impacts on the lands of the Nordic countries unprecedented since deglaciation some 10,000 year ago. Three ENVISNAR projects studying these processes are profiled below: