Man has never been content to leave the natural preserved in the state in which it was discovered. Likewise, the Everglades ecosystem has been bombarded by this pressure as man seeks to “redesign” the environment to suit the needs of the ever encroaching human population. This has brought about profound changes in this system and the way it operates. Collectors were among the first to extract a toll on this area because of its exotic indigenous creatures. Species which now face extinction include: several varieties of unusual Orchids and ferns, Florida tree snails, and the indigo snake.
But the impact of collectors is not merely limited to the disappearance of species. For example, collectors burned Hardwood Hammocks to facilitate collecting tree snails. The high demand for feathers as the plumes of ladies’ hats also endangered the Snowy Egret at one time. Another source of destruction includes off road vehicles such as air boats and swamp buggies used to negotiate the difficult terrain. These vehicles create ever widening soil ruts because the tracks are slippery and subsequent vehicles avoid them.
Because hydroperiod plays a powerful role in habitat determination, even a slight change in water depth can profoundly effect the composition of the ecosystem. Channels interrupting sheet flow provide an alternate route for the water. Vegetation is uprooted and lost, as a result, enhancing the likelihood of invasion by opportunistic species such as cattails. In some areas, off road vehicles have resulted in the damage of tree islands. Melaleuca, an Australian tree, poses a different kind of the threat: that of introduced species.
The trees overtake Sawgrass marshes and Cypress swamps in areas reduced by drainage. Their tolerance of fire further enhances their spread. Eventually, dense forests form which exclude the natural vegetation and dry up the environment. Brazilian pepper began its stay in the Florida area as an ornamental. Like the Melaleuca, it forms a closed forest, destroying feeding areas of many water birds. Brazilian pepper primarily overtakes coastal lowlands and pinelands. Over 200 plant species have been introduced “successfully” into the Everglades environment. Plants are not the only successful invaders.
The Blue Tilapia, an animal intruder, grows too large to be eaten by the wading birds, while creating a devastating effect on the aquatic plant life. By far the most serious effect of man on the environment remains the alterations of water flow patterns for agricultural and metropolitan purposes. The direct channeling of fresh water from Lake Okeechobee to the coast alters sheet flow, causing soil fires and saltwater backflow. Faced by these ever worsening scenarios, the Central and Southern Florida Project for Flood Control and Other Purposes (C&SF) took over the project in 1948.
First, the C&SF built a perimeter to prevent encroachment of the sheet flow on developing metropolitan areas. Second, agriculture reclaimed the Okeechobee by draining the Lake swamp and rerouting the water to the Water Conservation fertile land directly south of Areas to the south. Total, Water Conservation Areas, which regulate water flow toprevent flood and drought, now represent 32 % of the original Everglades ecosystem. Everglades National Park, established in 1947, only contains 25% of the historic freshwater system. Other problems facing this ecosystem include the loss of wild life species diversity.
Like the Snowy Egret, alligators, hunted for their hides, almost reached extinction until their sale was prohibited by law. Since that time, populations rebounded, however, bird populations still face intense reducing pressures. Wading birds follow the drying front during the drydown as the water flow concentrates prey at its border. Wading birds, therefore, only need make minor adjustments to determine the position of food daily. Consequently, larger rookeries and breeding seasons coordinate with the water flow so the drydown approaches the nest, allowing the parents to fly less distance every successive day.
The intrusion of the Water Conservation Areas though places this pattern in serious jeopardy. The levee system interrupts the drydown as conditions on one side may not correlate with conditions on the other. For example, birds following a drydown front may reach a levee only to discover that the across the embankment, the water is too deep or the drydown in that area may have already occurred. The birds then must search other areas for other prey concentrations which may not exist, seriously impairing successful reproduction.
Use of the conservation areas for flood control and unnatural releasing of water also adversely effects these communities. Often this reverses the drydown fronts. Changes in the dry/wet season cycle, likewise, affect alligator reproduction, interrupting courtship and often drowning their eggs. Alteration of alligator nesting patterns adversely affects the wading bird population because their holes customarily congregate prey during the low water season. Although, the canal construction provides alligators a substituted habitat, these canals are sufficiently deeper and steeper than traditional gator nesting holes.
Consequently, wading birds can not effectively harvest prey. Nutrient rich agricultural water released from the land reclaimed below Lake Okeechobee has increased the proliferation of cattails. Cattail encroached areas do not encourage food supplies for wading birds, essentially removing this wetland area from use. However, the South Florida Water Management District has begun an experimental program using peat soil beds to remove this phosphorus from the water supply entering the Everglades region. Methylmercury, a highly toxic form of mercury, recently has been found in regional fauna in unusually high levels.
The food web concentrates this chemical in the system’s top predators, causing mutations, abnormal growth and neurological disorders. Although, agriculture was originally blamed for this elevation, historical evidence provides a more accepted theory. According to this hypothesis, soil formations naturally trap small amounts of mercury. Recent drainage and oxidation of the soil caused its release. Sugarcane burning, and incineration of other products including fossil fuel have also received blame for this phenomenon. Interestingly though, an inverse relationship appears to exist between phosphorous and mercury levels.
The diversion of freshwater directly to the ocean from Lake Okeechobee also adversely affects Florida Bay. The lack of water cycling through the bay caused a severe increase in hypersalinity, killing seagrass beds, mangroves, fish, sponges, and birds. The hypersalinity level approximately doubles that of sea water. However, projects undertaken to remedy this situation appear to at least initially effective. Other reasons for this salinity increase include the lack of major storm systems recently in this area. Accumulation of sediments and shoaling prevent the bay from flushing out naturally, causing stagnation.
Also the construction of Highway 1 and the Overseas Railroad may have contributed to the problem, hampering further the circulation of water. Any attempt by man to undo the damage perpetrated must come from a comprehensive understanding of the function and operation of the original ecosystem in order to prevent further “well intentioned” catastrophes. Wading birds, because of their high position on the food chain, serve as trustworthy indicators of change on this fragile environment. However, the main problem to be address is not one of abuse of the Everglades in particular, but mankind’s underlying philosophy concerning our environment.
We must realize that our survival remains closely linked with that of our surroundings. Any threat to our biosphere will eventually cycle through and return to affect us. The restoration of the Everglades is an ongoing effort to remedy damage inflicted on the environment of southern Florida during the 20th century. It is the most expensive and comprehensive environmental repair attempt in history.  The degradation of the Everglades became an issue in the United States in the early 1970s after a proposal to construct a jetport in the Big Cypress Swamp.
Studies indicated the airport would have destroyed the ecosystem in South Florida and Everglades National Park.  After decades of destructive practices, both state and federal agencies are looking for ways to balance the needs of the natural environment in South Florida with urban and agricultural centers that have recently and rapidly grown in and near the Everglades. In response to floods caused by hurricanes in 1947, the Central and Southern Florida Flood Control Project (C&SF) was established to construct flood control devices in the Everglades.
The C&SF built 1,400 miles (2,300 km) of canals and levees between the 1950s and 1971 throughout South Florida. Their last venture was the C-38 canal, which straightened the Kissimmee River and caused catastrophic damage to animal habitats, adversely affecting water quality in the region. The canal became the first C&SF project to be reverted when the 22-mile (35 km) canal began to be backfilled, or refilled with the material excavated from it, in the 1980s. The restoration of the Kissimmee River is projected to continue until 2011.
When high levels of phosphorus and mercury were discovered in the waterways in 1986, water quality became a focus for water management agencies. Costly and lengthy court battles were waged between various government entities to determine who was responsible for monitoring and enforcing water quality standards. Governor Lawton Chiles proposed a bill that determined which agencies would have that responsibility, and set deadlines for pollutant levels to decrease in water. Initially the bill was criticized by conservation groups for not being strict enough on polluters, but the Everglades Forever Act was passed in 1994.
Since then, the South Florida Water Management District (SFWMD) and the U. S. Army Corps of Engineers have surpassed expectations for achieving lower phosphorus levels. A commission appointed by Governor Chiles published a report in 1995 stating that South Florida was unable to sustain its growth, and the deterioration of the environment was negatively affecting daily life for residents in South Florida. The environmental decline was predicted to harm tourism and commercial interests if no actions were taken to halt current trends.
Results of an eight-year study that evaluated the C&SF were submitted to the United States Congress in 1999. The report warned that if no action was taken the region would rapidly deteriorate. A strategy called the Comprehensive Everglades Restoration Plan (CERP) was enacted to restore portions of the Everglades, Lake Okeechobee, the Caloosahatchee River, and Florida Bay to undo the damage of the past 50 years. It would take 30 years and cost $7. 8 billion to complete. Though the plan was passed into law in 2000, it has been compromised by politics and funding problems.