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Lake Pátzcuaro (Spanish: ''Lago de Pátzcuaro'') is a lake in the municipality of Pátzcuaro, Michoacán, Mexico. The natives believe that the lake is the place where the barrier between life and death is the thinnest. Lake Pátzcuaro lies in an endorheic basin, which does not drain to the sea. A watershed area of 929 square kilometres drains into the lake, of which 126.4 are the water body. The Lake Pátzcuaro watershed extends 50 kilometres east-west and 33 kilometres from north to south. Lake Pátzcuaro lies at an elevation of 1,920 metres, and is the center of the basin and is surrounded by volcanic mountains with very steep slopes. It has an average depth of 5 metres and a maximum of 11. Its volume is approximately 580 million cubic metres.〔"Descripción de la cuenca", ''Recuperación Ambiental del Lago de Pátzcuaro". Accessed October 18, 2009. ()〕 The Lake Pátzcuaro basin is of volcanic origin. At times it has been part of an open and continuous hydrological system formed by Lake Cuitzeo, Pátzcuaro and Lake Zirahuén, which drained into the Lerma River. Today, like lakes Cuitzeo and Zirahuén, it is a closed basin, although ecologists consider it a sub-basin of the Lerma-Chapala basin.〔 ==Wetlands== The lake is surrounded by extensive wetlands. Cattails and other reedy vegetation are the dominant wetland vegetation, in dense stands over 2 meters tall. Typical wetland plant genera include ''Typha, Scirpus, Heleocharis,'' and ''Cyperus''. The dominant species of aquatic vegetation are ''Potamogeton illionoensis, Scirpus pectinatus,'' tule ''(Typha latifolia), T. dominguensis,'' and ''Nymphaea mexicana.''〔 The wetlands are extremely important for birds, both year-round inhabitants and migrating waterfowl. Close to 200 species inhabit the wetlands, including some endemic species such as the black-polled yellowthroat ''(Geothlypis speciosa)''. Two native species have not been observed recently; the yellow rail ''(Coturnicops noveboracensis)'' has not been seen since 1964 and may be locally extinct, and the endemic slender-billed grackle ''(Quiscalus palustris)'' is presumed extinct. The Lake Patzcuaro salamander ''(Ambystoma dumerilii)'' is endemic to the basin. The lake and its surrounding wetlands have undergone significant environmental changes over the past 50 years. logging and agriculture in the surrounding watershed have contributed to siltation of the lake (1 cm / year - 1.2 million cubic meters / year), and water diversion for agriculture and urbanization has reduced the size of the lake by 40 square kilometers, and 2.6 meters in depth. Other threats include untreated sewage, the introduction of exotic species, and chemical pollution.〔"Indicadores del deterioro ambiental", ''Recuperación Ambiental del Lago de Pátzcuaro". Accessed October 18, 2009. ()〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Lake Pátzcuaro」の詳細全文を読む スポンサード リンク
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