Concerns of the Canyon's Survival
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The Grand Canyon is at risk of surviving. Over the years, human activities have impacted the natural resources of Grand Canyon National Park in many ways. Humans have introduced non-native plant and animal species (invasive species) into the park, which outcompete native wildlife species for space, food and water. Invasive plants such as Sahara mustard pose a serious ecological threat to Grand Canyon. Air pollution has routinely drifted into the Canyon from densely populated urban areas and nearby coal-fired power plants, affecting visibility from scenic views. Water in some streams has been polluted with fecal coliform, a bacterium used to determine whether water has been contaminated with fecal matter. The presence of fecal coliform indicates the possible presence of organisms that can cause illness. Streams have been tainted with this bacterium from trespass cattle and from human waste. The construction of Glen Canyon Dam in 1963, irreversibly altered the river banks and aquatic ecosystems within the park. The natural quiet of Grand Canyon has been disturbed by rumbling aircraft noise (noise pollution), and the nearby forest landscapes have been altered by eliminating decades of wildland fires.