FRESH – Regional carp aquaculture as upgrader of resources for ecological sustainability and human health

The aim of FRESH is to establish a scientific basis for optimizing the use, metabolism, and trophic upgrading of natural food resources in carp aquaculture in Lower Austria. In light of the growing demand for resource-efficient and nutritionally valuable freshwater fish under changing climatic conditions, FRESH pursues an integrative research approach that combines aquatic ecosystem research, nutritional biochemistry, and applied aquaculture. At the core of the project are mesocosm experiments and feeding trials using pond-derived resources (plankton, insects) and cereal grains with varying oil compositions. The objective is to investigate how these feed combinations affect the utilization of essential fatty acids—particularly long-chain polyunsaturated omega-3 fatty acids (n-3 LC-PUFA)—in carp. The trials will be carried out in close cooperation with fish farmers, oilseed processors, and pond managers to ensure practical relevance. For the first time in freshwater aquaculture, FRESH will employ compound-specific stable isotope analyses to track the endogenous conversion of dietary fatty acids in the liver (hepatocytes) and their translocation into muscle tissue. This method allows for the direct quantification of trophic upgrading based on diet and provides new insights into fish nutritional physiology. The results aim to provide an evidence-based foundation for innovative, resource-efficient feeding strategies that enhance ecological sustainability, improve the nutritional value of regional fish production, and promote carp as a high-quality, climate-adapted dietary fish.