Human Impacts

Historically, the everglades covered almost three million acres. However, in the past hundred years, people have dug canals and built dams in the Everglades so they could take water out of it, which was used to develop agriculture and build homes. Unfortunately, the abundance of canals and dams has drained so much water that the natural flow is interrupted (12).

Additionally, early twentieth century conservationists saw the depletion of the Florida Everglades as the “smart, progressive” thing to do, yet this has resulted in the Everglades becoming less than half of its original size. There are over 1,800 miles of canals and dams along the everglades, with pump stations and water control points that divert natural water flow to coastal towns and cities (12).

Furthermore, Florida’s population is growing exponentially, and it has already reached about 6 million in southern Florida and is expected to double in the next fifty years. Unfortunately, this massive population growth has been accompanied by inland development, which has further reduced the size of the everglades. South Florida’s growing population also means that there needs to be an increase in residential development to accommodate the increase in amount of people. The population encroaches on the natural habitat of a diverse range of wildlife from insects to mammals, including fifteen species of reptiles and amphibians from Florida swamps that are currently listed as threatened or endangered (12).

This graph displays Southern Florida's population growth trend. Specifically, since the 1970s, Southern Florida's population has tripled! From roughly 2 million in the 70s, to almost 6 million people in 2010. (3)

People have also brought pollution, especially phosphorus from fertilizers, in the form of nutrient runoff into the Everglades. This nutrient runoff has allowed for the growth of species that upset the delicate balance of the ecosystem, such as duckweed. Sulfur, another harmful nutrient, leads to accumulations of toxic mercury in fish, birds, reptiles, and mammals through biological magnification. It is important to note that the surface water of the Everglades is naturally nutrient poor and this pollution via synthetic nutrients causes changes in the water quality, affecting both the aquatic and terrestrial species within the ecosystem (3 & 12).

Lastly, the Everglades faces danger from exotic plants and animals that have been introduced by humans. These exotic specimen displaced natives and threaten to disrupt the ecosystem balance. For  example the Burmese pythons, originally from Asia, are outcompeting and displacing native species such as native raccoons, possums, deer, and bobcats (8).

Number of Pythons in Everglades (y axis) vs. Year (x axis)

The graph shows that the invasive python population has generally increased exponentially on an annual basis, and numbers have tripled from 2005 to 2010 (8). This invasive species is decimating native species populations.