HUMAN IMPACTS
On Florida's Water Resources
HUMAN IMPACTS
On Florida's Water Resources
Florida's waters will always remain threatened by our human activities. No matter their essential ecologic and economic values and despite government and private efforts to guide our activities and protect our waters, some accidents will happen, some misguided actions will be allowed. Because water is literally the life-blood of our existence, we should each know what the threats are so that we can contribute, each in our own way, to helping reduce and counter the threats.
Since this web site is about invasive aquatic plants and their management, the threats listed below are those that directly contribute to invasive aquatic plant management problems in Florida.
| Invasive aquatic plants, almost all of them having been introduced by people, are taking their ecologic and economic tolls in Florida's waters and wet places. Their lack of natural controls in their new homes, their rapid growth rates, multiple reproductive methods, wide dispersal and survival, and broad environmental tolerances enable them to overpopulate and invade. In Florida, invasive plants include at least 100 exotic, non-native trees, grasses, vines, shrubs and ferns that smother, out-compete or otherwise replace our native plants. Melaleuca trees, Japanese climbing ferns, torpedograss, West Indian marsh grass, hydrilla, giant floating fern... we don't want any of them. Go here of this web site to view pictures of invasive aquatic plant infestations, "What We're Up Against". Go to this page for an introduction to invasive plants. Go back to the main index of this web site for much more information about invasive aquatic plants and their management. |
| Purposeful removal of native vegetation as well as beach construction by waterfront residents reduces parts of our shorelines to sterile enclaves that can have a cumulative negative effect: the more yards that become "mowed grass to the waterline", the less natural beauty and habitat there is. Loss of waterside vegetation deprives us humans of lovely natural vistas, but also leads to bank erosion and increased sedimentation, and greatly affects the wildlife that depend on the native plants for food, shade, and nesting. (Question: If a homeowner does not appreciate lovely natural vistas, and birds and other wildlife, why would they choose to live next to the water?) Ironically, removing native vegetation encourages non-native vegetation to take its place, thus requiring even more effort to keep the non-native plants out. Unknowing homeowners who clear their waterfronts often are only making more work for themselves. | 
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| "Pollution" is a very large term which covers all substances that are found where they shouldn't be. In our lakes, rivers and wetlands, pollution includes household pesticides and fertilizer runoff from local yards, parks and golf courses; parking lot runoff with its gasoline and oil; overflow from industrial ponds that may include toxic substances; and biological waste from animal farms and septic tanks. Different forms of pollution have different consequences, from the not-so-bad, to the positively deadly: too much fertilizer pollution makes algae and plants grow excessively and alters plant community structure; a gallon of gasoline pollution makes 1,000,000 gallons of water unfit for drinking; pesticide pollution can permeate the sediments and water table, kill small aquatic animals at the base of the food chain and poison residential wildlife; bacterial water pollution helps spread diseases such as cholera to humans and animals. Contaminants can create significant short-term and long-term effects in any wet or watery place where they are introduced. |
| Welling and overpumping reduces the level of the water-table. Water levels of most Florida rivers, lakes, springs and wetlands are directly related to annual precipitation and the level of the water table. Overpumping of water lowers the water-table and dramatically affects the marsh environment by altering natural marsh processes such as wildlife activity, peat development, plant composition. When our wet environments become dry, they often are invaded by certain non-native plants that are tolerant of wet and dry conditions. Welling and pumping can reduce the amount of water discharged from a spring. In 1950, Kissengen Spring in Polk County stopped flowing because of excessive pumping. Salt: Groundwater can become contaminated by pockets of ancient seawater found deep under Florida, or by modern seawater intrusion along coast. This frequently occurs in areas of excessive pumping, which causes subsurface saltwater to be sucked inland to replace extracted freshwater. | 
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| Draining is the primary historic cause of degradation of the state's wetlands. Many of Florida's marshes have been drained in response to the growing demand for farming and cattle grazing, and to create dry land for new homes for Florida's increasing population. Draining dries up wetlands, swamps and marshes, or disrupts natural water level fluctuations in them, thereby altering their native plant and animal communities; draining also makes wetlands much more susceptible to invasions by non-native plant species. |
| Some agricultural activities can lead to increased spread and growth of invasive plants, as well as otherwise degrade our watery places. Surface runoff from farms carries animal wastes which act as fertilizers to cause increased plant growth as well as algae blooms. Unhealthy nitrates contained in the waste can enter the aquifer through sinkholes, or can enter the nearby rivers, lakes and wetlands. Hay and other products moved from one farm to another often spreads invasive non-native plants such as several species of nightshade. |
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| Physical alterations of floodplain forest swamps, alterations such as road construction and ditch digging, changes water flow patterns, thus altering natural flood control and adversely raising and lowering water levels in other areas, thus encouraging and sustaining non-native plant invasions. Rivers and lakes can be degraded by constructions such as dams, boat ramps and bulkhead channels. Alterations in the surrounding terrain can disrupt a lake's natural processes and create unplanned changes in flood patterns, sedimentation, water quality and water clarity, and can also disturb native plants and animals. Damming rivers and lakes disrupts water cycles and does not allow natural drying and burning cycles to occur. The result is a system dominated by dense growth of aquatic and wetland plants and rapid accumulation of thick organic sediment deposits. Construction of roads disrupts natural water flow and filtration, increases human presence in wilderness, and facilitates spread of non-native invasive plants at least along road beds. Roads greatly affect natural habitats and the wildlife that depend on cyclical water cycles and isolation from human activity. |
| Unmanaged recreational activities by too many tubers, canoers, swimmers, scuba divers, fossil hunters and boaters results in destroyed native vegetation and over-disturbed lake and river bottoms and wetlands, and subsequent encouragement of invasive plant species. Bank erosion at springs increases as the number of visitors steadily rises. Trampling causes sedimentation along the banks, disturbs wildlife, smothers aquatic plants, and reduces water clarity. Most of us know of favorite recreational spots that are being "loved to death" because of too many people and not enough management. | 
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| Logging valuable timber takes its toll especially in swamps; swamps make up a quarter of Florida's commercial forest land. When swamps are disturbed by logging and other rough activities, and left to grow back on their own, the chances are that invasive species, such as non-native trees and vines, will invade the area. When cypress stands are timbered, they regenerate with ash, maple, gum, and bay trees, thus altering the swamp ecosystem long-term and immediately affecting wildlife populations and water quality downstream. The disappearance of the ivory billed woodpecker and the Carolina parakeet has been attributred to logging in wetlands. |
| Phosphate mining for fertilizer production is a major industry in Florida; our wetlands are a primary source of the world's phosphate. Phosphate mining and peat mining (substrate removal) destroy swamp and marsh habitats. Efforts are made to reclaim these wetlands after mining, but wetland restoration is difficult at best, and invasive plants often take advantage of these unnatural systems. While phosphate lands are private lands, the non-native plants that invade their created wetlands also can invade adjacent public wildlands. Learn about phosphate mine reclamation efforts from the Florida Phosphate Council. | 
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| Garbage and junk dumping is unfortunately all too common in our unprotected waters. Our lakes, rivers, sinkholes and drainage systems often end up being receptacles for all sorts of waste, some of which migrates directly into the water supply. |
This page was authored by Sarah Cervone and Vic Ramey, with assistance from Becca
Hassell.
Data is from the APIRS
database.
Photography and graphics are by Ann Murray, Sara Reinhart, Vic Ramey and Jeff Schardt.
Vic Ramey is the editor.
DEP review by Jeff Schardt and Judy Ludlow.
