Long-term Dynamics of Fish Populations

This project is the first comprehensive study of the long term development of riverine fish communities from the late Middle ages onwards until present. It will be done within the framework of a bilateral cooperation between interdisciplinary research teams of river and fish ecologists, environmental historians and archaeologist from Austria and Russia. The spatial focus will be on representative Alpine catchments (Salzach) and rivers from the Russian North as well as on rivers in urban environments (Vienna on the Danube, St. Petersburg on the Neva, Pskov on the Velikaya). The case studies will offer the possibility to analyse different natural but also different societal conditions. Our research is motivated by several research questions addressing methodological issues relevant for the reconstruction of past ecological conditions on the one hand and particular societal and natural conditions investigated in case studies on the other hand. The project will consist of three main research topics. The first one will define a comprehensive methodology for analysing long-term changes of riverine fish populations. This methodology will use existing studies providing approaches for particular issues. It will also build on existing fish ecological knowledge of species traits and habitat-fish relationships. The second research topic will be dedicated to the case studies. Each case study will reconstruct long-term changes of fish communities and populations, climate and in particular temperature change as well as the societal alterations of fish communities and the riverine habitat. These three elements will enable us to interpret long-term fish ecological changes against the background of dominating natural and human driving forces. In the third research topic we will elaborate spatial differences in the historical development of fish communities through a cross national comparison. We will draw general conclusions on how different environmental and societal processes shaped fish populations and establish a final conceptual framework. The methodology and the conceptual framework for analysing the historical development of riverine fish population will be main outputs of the project. They can be applied to other historical ecological studies of river fish communities. The results can be also relevant for effective future river management and contribute to the crucial task of defining restoration targets by highlighting historical legacies acting in present riverine landscapes and by showing patterns of the long-term evolution of river ecosystems. Our study will produce a multitude of results related to fish ecology, climate change and societal modifications of river systems and the interaction between them as well as to methodological issues. They will be synthesized in scientific papers addressed to different target groups and be presented in various scientific conferences.