Climate Change Effects on Freshwater Biodiversity

Freshwater ecosystems harbour a disproportionate share of global biodiversity yet rank among the most threatened habitats under climate change. Rising water temperatures, altered flow regimes and increased frequency of extreme events are driving shifts in species distributions, phenology and community composition. Cold‐water specialists and pollution‐intolerant taxa often decline as warm‐affinity species proliferate, with consequences for food-web structure and ecosystem function. Oxygen limitation under warming exacerbates stress on ectotherms, reducing survival and sublethal performance. At the same time, nutrient enrichment and land-use change interact with thermal stress to undermine long-term recovery efforts. These combined pressures can stall or reverse gains achieved by water-quality improvements and restoration projects, highlighting the need for adaptive management that integrates hydrological, chemical and thermal factors.

Research from Nature Portfolio

Recent studies have documented a halt in the recovery of European freshwater invertebrate communities despite earlier gains from restoration and wastewater treatment. In many regions, taxon and functional richness increased until the early 2010s but have since plateaued, particularly downstream of dams and in urban or agricultural landscapes. Warming trends have been directly linked to reduced biodiversity gains at sites experiencing the fastest temperature increases. Parallel work across temperate freshwater and terrestrial assemblages has revealed widespread thermophilisation, with the rate of warm-affinity species turnover modulated by body size, thermal niche breadth and baseline temperatures. Long-term monitoring of a major Chinese wetland further emphasises how intensified land-use close to waterbodies drives declines in macroinvertebrate alpha diversity, while increasing beta diversity as communities become more dissimilar at fine spatial scales. These findings underscore the interplay of climate and land-use pressures in shaping community resilience and recovery potential.

Climate Change Effects on Freshwater Biodiversity publication trend

The graph below shows the total number of articles in climate change effects on freshwater biodiversity across all publications each year (not limited to Nature Index journals).

Technical terms

Taxon richness: number of distinct taxa present within a community.

Functional richness: range of ecological functions or traits represented by species in a community.

Thermophilisation: shift in community composition favouring warm-affinity species under rising temperatures.

Alpha diversity: diversity measured within a specific habitat or site.

Beta diversity: variation in species composition among sites or over time.

References

1. The recovery of European freshwater biodiversity has come to a halt. Nature (2023).
2. Warming underpins community turnover in temperate freshwater and terrestrial communities. Nature Communications (2024).
3. Long-term wetland biomonitoring highlights the differential impact of land use on macroinvertebrate diversity in Dongting Lake in China. Communications Earth & Environment (2024).
4. Density declines, richness increases, and composition shifts in stream macroinvertebrates. Science Advances (2023).
5. Climate warming drives population trajectories of freshwater fish. Proceedings of the National Academy of Sciences of the United States of America (2024).
6. Field and laboratory studies reveal interacting effects of stream oxygenation and warming on aquatic ectotherms. Global Change Biology (2016).