586 Freshwater Ecosystems, Human Impact on river systems to extinction Several species of freshwater fish have gone extinct during the past few centuries, and many additional species of plants, large invertebrates, fish, and frogs now exist in extremely small and geographically isolated populations These species face a great risk of extinction, and they can no longer provide their accustomed ecosystem functions Nor can these species be enjoyed within most of their native area Unfortunately, they will find it exceedingly difficult to recolonize newly restored aquatic habitat and contribute to future speciation See also: Agriculture, Industrialized Endangered Freshwater Invertebrates Freshwater Ecosystems Human Impacts on Ecosystems: An Overview Wetland Creation and Restoration References Allan JD (1995) Stream Ecology Structure and Function of Running Waters London: Chapman & Hall Clark JM, Bottrell SH, Evans CD, et al (2010) The importance of the relationship between scale and process in understanding long-term DOC dynamics Science of the Total Environment 408: 2768–2775 Hesthagen T, Fjellheim A, Schartau AK, Wright RF, Saksga˚rd R, and Rosseland BO (2011) Chemical and biological recovery of Lake Saudlandsvatn, a formerly highly acidified lake in southernmost Norway, in response to decreased acid deposition Science of the Total Environment 409: 2908–2916 Kristensen P and Hansen HO (eds.) (1994) European rivers and lakes – Assessment of their environmental state Copenhagen: European Environment Agency EEA Environmental Monographs, vol Petts GE (1984) Impounded Rivers Chichester, United Kingdom: John Wiley & Sons Williams P, Whitfield M, Biggs J, et al (2003) Comparative biodiversity of rivers, streams, ditches and ponds in an agricultural landscape in southern England Biological Conservation 115: 329–341