“In the end we will conserve only what we love; we will love only what we understand;
and we will understand only what we have been taught.”
– Baba Dioum

When one hears the word “wetlands” or any other synonym related to it (swamp, marsh, bog, etc.), it usually conjures up images that are less than favorable.  In fact, early settlers commonly related these ecosystems with disease, referring to yellow fever garnered from mosquitoes as “swamp fever” or constantly warning their children not to get too close to the “swamp vapors,” for fear that they might catch some unwanted illness.

Many people, even those who have a great love for wildlife, have been taught that wetlands are “wastelands” which serve no purpose unless they are drained and put to use. With numerous years of viewing wetlands in this negative light, it might come as a surprise that wetlands actually contain a wide and incredibly beneficial variety of functions.

In order to protect this dynamic ecosystem, the public must first recognize the values of wetlands.

Just from looking at a wetland, it can be very hard to conjecture at what kind of uses it contains. But these little pieces of wonder, despite early opinion that they were of better used drained and converted to farmland, serve many functions that make them valuable in their natural state. These functions include: flood control, erosion control, water quality and availability, atmospheric maintenance, fish and wildlife habitat, natural resources, and opportunities for recreation, education, research, and aesthetic appreciation.

• Flood control
Perhaps one of the most important aspects of a wetland is its ability to function as a natural sponge. Normally floodplains cover wide areas of certain geographical regions, floodplains allow the flow of water through large geographical areas, eventually dumping into another source of water. The wetland absorbs water during heavy rainfall, snowmelt, or from flood waters and then slowly releases it downstream. Trees, bushes, shrubs, and other wetland vegetation all help to impede the flow of water through the wetland, thereby decreasing the velocity of water coming through, and simultaneously absorbing much of the water into the water table situated below. As floodwaters move across a floodplain, this combined water storage and braking action lowers flood heights and prevents waterlogging of agricultural lands.

Perhaps of even more value is the protection a wetland offers in an urban setting. Because of its flood control capabilities, a wetland is able to counteract the increased rate and volume of water runoff from pavement and office buildings.

On the other end of the spectrum, when a stream or waterway becomes dry in arid weather, a wetland (because of its nearness to groundwater) discharges its water into the nearby body of water. In essence, it is the gatekeeper between dry and wet land.

• Erosion control
Storm surges, hurricanes, and all tropical storms cause incredible damage to nearby coastline through flooding and destruction of property. Many times coastal wetlands act as buffers towards these storms. They are the first line of defense, as they reduce wind and wave energy, plus reducing currents that flow into them from water surges. The large, steadfast roots of wetlands vegetation hold the soil and sand in place, preventing or minimizing shoreline erosion.

• Water quality and availability
Much as the human kidney filters out the bloodstream of toxic and harmful products, so do wetlands function to purify water that runs through it. As has been noted that wetlands intercept surface-water runoff from higher uplands before it dumps into open water, their filtering capabilities are of extreme importance. Once water containing chemicals, pollutants, and unwanted sediment from upstream flow through the water in wetlands, this water is slowed down and filtered in a seemingly simple process. The simple slowing of water allows for suspended sediment to drop and settle on the wetland floor. This turns out to be beneficial further downstream where this deposition of sediment may eventually block waterways.

At the same time, nitrogenous and phosphorous wastes (associated with pesticide use from upstream) are processed or retained by wetland plants that are adapted to breaking down or actually using these potentially harmful chemicals. Other organic pollutants are easily decomposed in the same manner. This purification of the water stops the negative effects agricultural runoff could have on fish and amphibian development once the runoff reaches rivers, lakes, and oceans. It is also important to note that the prevention of these harmful chemicals reaching groundwater ensures a higher quality of water to humans that rely on groundwater supplies for drinking water.

Wetlands also combat the environmental problem of eutrophication—which leads to rapid algal growth and depleted oxygen levels that affect other species—by eliminating the excess nutrients that cause the problem to begin with. As beneficial of a process that this water purification seems, the public must be aware that the capacity of wetlands to function in this manner is limited, as overloading the wetland with chemicals and sediment can destroy the wetland entirely.

• Atmospheric maintenance
One aspect of wetlands that might not be as well-known is their ability to store carbon within their plant biomass (peat) in place of releasing it into the atmosphere.  What would normally be released into the atmosphere as the greenhouse gas carbon dioxide is now trapped in the peat, helping to maintain global climates. Consequently, by clearing these types of wetlands, high levels of carbon dioxide are released into the atmosphere—yet another cause of global warming.

• Fish and wildlife habitat (biodiversity)
Although it might not be clear at first glance, wetlands sustain a warehouse of organisms ranging from microscopic bacteria to alligators to rare flowers. Some scientists state that wetlands are comparable to coral reefs and tropical rainforests in their biodiversity. Much of the wildlife contained within a wetland is wetland-dependent and are only found in these special ecosystems. They rely on the products produced by and shelter provided by wetlands. Many of these species are on the endangered or threatened species list, so it is a wonder why we continue to destroy these precious pieces of concentrated biological diversity. Our own Cahaba River in Alabama contains some 131 species of fish, 18 of which are only found in this river. “There are more fish species per mile in the Cahaba than in any other North American river” (www.wwf.org). The endangered Cahaba lily is also found only in this region, thanks in part to its sustainability by wetlands.

Wetlands contain the essential ingredients for the development of organisms that form the base of the food web. The combination of high levels of inorganic nutrients, shallow water, and high rates of primary productivity (plant tissue built up over time through photosynthesis) help attract many species of insects, mollusks, and crustaceans. As plant material begins to break down into smaller particles, fungal and bacterial activity cause it to become increasingly enriched with nutrients. This becomes food for smaller fish which then serve as food for larger predators such as amphibians, birds, reptiles, and mammals. The food web active within a wetland is one unto itself.

Wetlands provide the principal habitat for virtually all waterfowl. Some 75% of all waterfowl breed only in wetlands. Certain wetlands act as migratory “pit stops,” so to speak, during a flock’s cross-country travels. Also, waterfowl, wading birds, and many other animals (particularly amphibians) require water as a medium to mate and/or for the growth and development of their young. While wetlands may be intermediate or seasonal habitats for some, animals (such as the American alligator, blue heron, many species of ducks, and a vast number of amphibians) use wetlands as their primary habitat.

• Natural resources
As is the case with most other ecosystems, we humans use various natural products from wetlands in the form of timber, mammals, fish, shellfish, medicinal plants, and peat. Certain non-medicinal plants are also grown in wetlands; these include blueberries, cranberries, and strawberries. Common fur-bearers like the muskrat, beaver, otter, and mink all make their homes in wetlands, as do alligators, which are valued for their skin and meat. Without a doubt, the most abundant natural resources stemming from wetlands are fish and shellfish. The National Marine Fisheries Service estimates that almost 70% of the annual commercial fish catch depends upon inshore-wetland habitats. (Sierra Club)

• Recreation, education, research, aesthetic appreciation
Aside from providing various beneficial environmental benefits to us, wetlands also serve as lucrative spots for many rewarding pastimes. They are ideal tourist spots for more than one occasion. According to the EPA, nearly half the adult population of the United States is involved in hunting, fishing, boating, birdwatching, or photographing wildlife, “annually spending a total of $59.5 billion in the process.” Coastal wetlands bring in the same numbers of people and money, mainly through the marine fishing industry and wetland-dependent recreational fishing. Whether you are a scientist looking to research water quality or plant life, an avid birdwatcher hoping to snap a contest-winning photograph, a hunter waiting in the trees for the next deer to walk by, a fisherman wanting to try out some new gear, or simply a person in need of a beautiful landscape to put your mind at ease, wetlands have your name written all over them.

“Not all wetlands perform all functions, nor do they perform all functions equally well. The location and size of a wetland may determine what functions it will perform.”
(U.S. Geological Survey)




Web page updated: August 25, 2004 3:13 PM
Copyright © 2004 Samford University. Questions or comments?
Please contact the Alabama Wetlands Committee or the Department of Biology.