International cooperation helps assess effects of climate change on health of Arctic Rivers

Climate change has dramatic effects on freshwater ecosystems in the Arctic through alterations of the chemical and physical environment. However, the lack of internationally coordinated monitoring of freshwater plants and animals hinders our ability to assess changes caused by climate shifts. To address the need for such coordinated, circumpolar monitoring, the Arctic Council formed the Circumpolar Biodiversity Monitoring Program (CBMP), which is focused around four ecosystem themes (Terrestrial, Freshwater, Coastal, Marine). The CBMP has produced important circumpolar assessments that document the current state of Arctic biodiversity. Freshwater-CBMP compiled and analyzed a vast amount of monitoring data from more than 9000 sites across the Arctic to produce the first assessment of biodiversity status and trends in these freshwaters. Diversity was lowest at high latitudes due to constraints imposed by temperature and ice regimes. In addition, the shortage of land mass connections restricts the dispersal of species. We hypothesize that the northward expansion of species ranges into southern Arctic regions may lead to large changes in the state of freshwater ecosystems and produce negative, interspecific competition effects for organisms adapted to cold environments. Ultimately, these changes to freshwater ecosystems can cause irreversible extinction of unique Arctic plants and animals. Such circumpolar assessments of Arctic freshwater biodiversity provide important baseline information, and are useful to researchers, policy makers, and Indigenous and local communities.