Distinctive Climate Change Features in Latvia and Their Implications for Freshwater Ecosystems

Climate change is increasingly affecting freshwater ecosystems across Northern Europe, yet the responses of inland waters differ according to regional climatic and environmental conditions. Latvia, located within the boreo-nemoral transition zone, provides an important case for understanding these responses. This review synthesises published evidence on climate-driven changes in Latvian inland surface waters by integrating information on climatic trends, hydrological processes, hydrochemical responses and freshwater biota. The available evidence indicates that increasing air temperature, changing precipitation patterns and more frequent hydrological extremes have altered river discharge, ice regimes, water temperature and lake processes. These hydrological changes generate cascading effects on nutrient transport, dissolved organic matter and water quality, ultimately influencing primary production, community composition, species redistribution and fish communities. The review identifies hydrology as the principal mechanism linking climatic forcing with hydrochemical and biological responses. Although the overall direction of change is consistent with observations across Northern Europe, local catchment characteristics and multiple stressors modify ecosystem responses in Latvia. The synthesis also identifies major knowledge gaps regarding ecosystem-scale processes, ecological thresholds and long-term integrated monitoring. Addressing these gaps will improve understanding of climate-driven changes in Latvian inland waters and strengthen the scientific basis for adaptive freshwater management in Latvia and comparable northern European regions.