<p>Within the framework of the TeichFit research project, nine fishponds in the District of Gmünd (Lower Austria) were investigated regarding their importance for water balance, water quality, climate regulation, and biodiversity. The results demonstrate that ecologically intact ponds can provide high-quality and healthy fish when appropriate management, feeding practices, and food preparation are applied. Herbicide concentrations measured in the ponds were below legal threshold values, indicating effective retention and dilution processes within the pond systems. In addition, sustainably managed fish ponds produce high-quality food and contribute to the supply of highly required omega‑3 fatty acids through carp production. Stable water isotope analyses (δ²H and δ¹⁸O) revealed pond-specific evaporation patterns and long water residence times. The ponds respond sensitively to climatic changes and therefore serve as indicators of climate change impacts. Long-term monitoring further revealed a&#xa0;significant increase in water temperatures since the 1960s and projects continued warming throughout the twenty-first century. The high structural diversity of the investigated pond landscape supports exceptionally high biodiversity. Species richness of phyto- and zooplankton was approximately three times higher than that observed in comparable mountain lakes, highlighting the importance of these ponds as biodiversity hotspots and providers of essential ecosystem services. The findings demonstrate that the Waldviertel pond landscape extends far beyond its traditional role in fish production and plays a&#xa0;crucial role in water resource management, climate resilience, biodiversity conservation, and sustainable regional development.</p>