Freshwater biodiversity and climate change

Freshwater ecosystems are particularly vulnerable to the effects of climatic change because many are already degraded by existing stressors. Increasing agricultural production and urban development, fundamentally driven by global population growth, have resulted in major changes in water use and land management. In addition to direct climatic impacts, it is the indirect impacts arising from interactions with existing stressors that may have the largest negative effects on freshwater ecosystems. However, not all scenarios are negative. The boom and bust ecosystems of arid and semi-arid regions (comprising more than 70 of the Australian continent) are highly resilient to climatic variability. For these systems, the protection of refugia, which support populations during dry times, is of utmost importance. Additionally, the processes supporting dispersal and recolonisation also need protection. To reduce the predictive uncertainties created by the confounding effects of multiple pre-existing stressors, long-term monitoring programs are needed at sites where the only major impact is climatic change.