HUMAN IMPACTS ON FRESHWATER ENVIRONMENTS ENDANGER MANY SPECIES
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FIGURE 6.18 The Colorado pikeminnow, the largest minnow native to North America, has become endangered as a result of dam building, altered temperatures, and the introduction of non-native species to its habitat. In addition, more species of freshwater mussels are native to North America than anywhere else in the world. However, up to 70% of them are extinct or threatened by overharvesting, dam building, sedimentation, and competition with invasive species. Finally, the Yangtze River dolphin, or Baiji, one of very few freshwater dolphin species in the world, was driven to extinction in the late 20th century as a result of unintentional killing by various fishing methods, pollution, and habitat alteration.
(Ben Kiefer/UDWR) (USFWS photo by Andy Roberts) (Xu Jian/Nature Picture Library)