<P> Many pets have escaped or been released into the Everglades from the surrounding urban areas . Some find the conditions quite favorable and have established self - sustaining populations, competing for food and space with native animals . Many tropical fish have been released, but blue tilapias (Oreochromis aureus) cause damage to shallow waterways by creating large nests and consuming aquatic plants that protect native young fish . </P> <P> Native to southern Asia, the Burmese python (Python molurus bivittatus) is a relatively new invasive species in the Everglades . This species can grow up to 20 feet (6.1 m) long, and they compete with alligators for the top of the food chain . Florida wildlife officials speculate that escaped pythons have begun reproducing in an environment for which they are well - suited . In Everglades National Park alone, agents removed more than 2,000 Burmese pythons from the park as of 2017 . Federal authorities banned four species of exotic snakes, including the Burmese python, in 2012 . The pythons are believed to be responsible for drastic decreases in the populations of some mammals within the park . </P> <P> The invasive species that causes the most damage to bird populations is the cat (Felis catus), both domestic and feral . Cats that are let outside live close to suburban populations and have been estimated to number 640 per square mile . In such close numbers in historic migratory areas, they have devastating effects on migratory bird populations . </P> <P> Though scientists made headway in decreasing mercury and phosphorus levels in water, the natural environment of South Florida continued to decline in the 1990s, and life in nearby cities reflected this downturn . To address the deterioration of the Miami metropolitan area, Governor Lawton Chiles commissioned a report on the sustainability of the area . In 1995, Chiles published the commission's findings in a report that related the degradation of the Everglades ecosystems to the lower quality of life in urban areas . The report noted past environmental abuses that brought the state to a position to make a decision . Not acting to improve the South Florida ecosystem, the report predicted, would inevitably cause further and intolerable deterioration that would harm local tourism by 12,000 jobs and $200 million annually, and commercial fishing by 3,300 jobs and $52 million annually . Urban areas had grown beyond their capacities to sustain themselves . Crowded cities were facing problems such as high crime rates, traffic jams, severely overcrowded schools, and overtaxed public services; the report noted that water shortages were ironic, given the 53 inches (130 cm) of rain the region received annually . </P>

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