OBSOLETE: Trends in biodiversity: freshwater

Abstract

About 10% of known species inhabit freshwater habitats, even though freshwater comprises less than 1% of Earth's surface. Hundreds of new freshwater fish species are described each year, mostly from the tropics. Freshwater ecosystems and their species are stressed by multiple human impacts, including dams that alter flows and fragment habitat, fishing, pollution, and exotic species. Most of North America's freshwater mussel species are either threatened or extinct, and numerous freshwater crustacean and fish species are threatened. Dozens of freshwater fishes have gone extinct in North America, more than for all other continents. Amphibian diversity has declined globally, with climate change and disease being major factors. Climate change, especially shifting precipitation patterns, will affect freshwater biodiversity, inland fisheries, and other ecosystem services. Adaptation to climate change will require resiliency in both ecosystems and management systems.