RESEARCH ON THE EVOLUTION OF WATER QUALITY PARAMETERS IN FISH PONDS DURING THE COLD SEASON IN THE CONTEXT OF CLIMATE CHANGE

The paper presents scientific data and information resulting from monitoring the most important water quality parameters in the pond during the cold season (November 2024 – March 2025), in order to assess the impact of climate change on aquatic ecosystems used for fish farming. The analysis focused on physical parameters (water temperature and turbidity) and chemical parameters (dissolved oxygen, salinity, pH, and nitrogen compounds), tracking variations specific to periods of low temperatures and their influence on fish wintering conditions. The results obtained highlight the major role of climate fluctuations in altering the ecological balance of fish ponds and emphasize the need to apply monitoring and adaptive management measures to maintain the productivity and sustainability of fish farming systems. Therefore, the physical parameters had average values between 3.35 and 10.65°C for water temperature, and turbidity fluctuated, with some occasional increases, but in general the values remained low. The values of the chemical parameters monitored showed relative stability of pH and high levels of dissolved oxygen (≈9–10 mg/L), nitrites (NO₂⁻) and nitrates (NO₃⁻) had low values, with no risk of toxicity, but ammonium (NH₄⁺) showed moderate variations between ponds, within the limits accepted in aquaculture, indicating efficient management ofmineralization processes. The warming trend in water temperature is a major challenge for the sustainability of aquaculture.