Wetland Creatures
Vinay Pettyjohn
Swamps, bogs and marshes might conjure mysterious, foggy images of stagnant water and slimy mud. But wetlands are active, dynamic and vibrant places where an incredible web of life exists in careful balance.
Wetlands are important features in the landscape that provide numerous beneficial services for people and for fish and wildlife. Some of these services, or functions, include protecting and improving water quality, providing fish and wildlife habitats, storing floodwaters and maintaining surface water flow during dry periods. These valuable functions are the result of the unique natural characteristics of wetlands.
Wetlands are among the most productive ecosystems in the world, comparable to rain forests and coral reefs. An immense variety of species of microbes, plants, insects, amphibians, reptiles, birds, fish and mammals can be part of a wetland ecosystem. Climate, landscape shape (topology), geology and the movement and abundance of water help to determine the plants and animals that inhabit each wetland. The complex, dynamic relationships among the organisms inhabiting the wetland environment are called food webs. This is why wetlands in Texas, North Carolina and Alaska differ from one another.
Wetlands can be thought of as "biological supermarkets." They provide great volumes of food that attract many animal species. These animals use wetlands for part of or all of their life-cycle. Dead plant leaves and stems break down in the water to form small particles of organic material called "detritus." This enriched material feeds many small aquatic insects, shellfish and small fish that are food for larger predatory fish, reptiles, amphibians, birds and mammals.
The functions of a wetland and the values of these functions to humans depend on a complex set of relationships between the wetland and the other ecosystems in the watershed. A watershed is a geographic area in which water, sediments and dissolved materials drain from higher elevations to a common low-lying outlet or basin a point on a larger stream, lake, underlying aquifer or estuary.
Wetlands play an integral role in the ecology of the watershed. The combination of shallow water, high levels of nutrients and primary productivity is ideal for the development of organisms that form the base of the food web and feed many species of fish, amphibians, shellfish and insects. Many species of birds and mammals rely on wetlands for food, water and shelter, especially during migration and breeding.
Wetlands' microbes, plants and wildlife are part of global cycles for water, nitrogen and sulfur. Scientists now know that atmospheric maintenance may be an additional wetlands function. Wetlands store carbon within their plant communities and soil instead of releasing it to the atmosphere as carbon dioxide. Thus wetlands help to moderate global climate conditions.
Far from being useless, disease-ridden places, wetlands provide values that no other ecosystem can. These include natural water quality improvement, flood protection, shoreline erosion control, opportunities for recreation and aesthetic appreciation and natural products for our use at no cost. Protecting wetlands can protect our safety and welfare.
We use a wealth of natural products from wetlands, including fish and shellfish, blueberries, cranberries, timber and wild rice. Some medicines are derived from wetland soils and plants. Many of the nation's fishing and shellfishing industries harvest wetland-dependent species. In the Southeast, for example, nearly all the commercial catch and over half of the recreational harvest are fish and shellfish that depend on the estuary-coastal wetland system. Louisiana's coastal marshes are tremendously valuable for their commercial fish and shellfish harvest. Wetlands are habitats for fur-bearers like muskrat, beaver and mink as well as reptiles such as alligators.
More than one-third of the United States' threatened and endangered species live only in wetlands, and nearly half use wetlands at some point in their lives. Many other animals and plants depend on wetlands for survival. Estuarine and marine fish and shellfish, various birds and certain mammals must have coastal wetlands to survive. Most commercial and game fish breed and raise their young in coastal marshes and estuaries. Menhaden, flounder, sea trout, spot, croaker and striped bass are among the more familiar fish that depend on coastal wetlands. Shrimp, oysters, clams, and blue and Dungeness crabs likewise need these wetlands for food, shelter and breeding grounds.
For many animals and plants such as wood ducks, muskrat, cattails and swamp rose, inland wetlands are the only places they can live. Beaver may actually create their own wetlands. For others, such as striped bass, peregrine falcon, otter, black bear, raccoon and deer, wetlands provide important food, water or shelter.
Many of the U.S. breeding bird populations-- including ducks, geese, woodpeckers, hawks, wading birds and many song-birds-- feed, nest and raise their young in wetlands. Migratory waterfowl use coastal and inland wetlands as resting, feeding, breeding or nesting grounds for at least part of the year. Indeed, an international agreement to protect wetlands of international importance was developed because some species of migratory birds are completely dependent on certain wetlands and would become extinct if those wetlands were destroyed.
Wetlands function as natural sponges that trap and slowly release surface water, rain, snowmelt, groundwater and flood waters. Trees, root mats and other wetland vegetation also slow the speed of flood waters and distribute them more slowly over the floodplain. This combined water storage an braking action lowers flood heights and reduces erosion.
Wetlands within and downstream of urban areas are particularly valuable, counteracting the greatly increased rate and volume of surface- water runoff from pavement and buildings. The holding capacity of wetlands helps control floods and prevents water logging of crops. Preserving and restoring wetlands together with other water retention can often provide the level of flood control otherwise provided by expensive dredge operations and levees. The bottomland hardwood- riparian wetlands along the Mississippi River once stored at least 60 days of floodwater. Now they store only 12 days because most have been filled or drained.
These stories sound fanciful to modern ears but have roots in real-life concerns of our peasant ancestors, few of whom could swim even though their villages were often located near water. Tales of spirits and demons probably helped instill an appropriate caution about wetlands in both children and adults. Surely many a peasant girl warned of the Rusalki when her fianc headed to the tavern, lest he stumbles tipsily into the town pond on his way home.1. Jenny Greenteeth
In the swamps and billabongs of Australia lurks the Bunyip, a beast of Aboriginal mythology that acts as a kind of wetland guardian. An ancient tale tells of two brothers who were turned into Black Swans and their village flooded after they captured a Bunyip calf. Descriptions lead scientists to believe the legend may stem from Aboriginal encounters with the bones of large, now-extinct wetland marsupials or perhaps the carcass of an elephant seal that wandered far inland and died on a riverbank.8. Heqet
More than one-third of the U.S. federally threatened and endangered species live only in wetlands, and nearly half use wetlands at some point in their lives. Numerous other animals and plants depend on wetlands for their survival. For many animals and plants, like wood duck, muskrat, cattail, and swamp rose, inland wetlands are the only places they can live. Coastal wetlands are key to the survival of many estuarine and marine fishes and shellfish as well as birds like the saltmarsh sparrow.
Most commercial and game fish breed and raise their young in coastal marshes and estuaries. Menhaden, flounder, sea trout, spot, croaker, and striped bass all depend on coastal wetlands. Shellfish like shrimp, oysters, clams, and blue and Dungeness crabs likewise need these wetlands for food, shelter, and breeding grounds.The U.S. Fish and Wildlife Service's (Service) Coastal Program promotes cooperative coastal conservation so that wildlife and people thrive. By facilitating voluntary collaborative conservation, the Coastal Program ensures a thriving and resilient future for coastal habitats, species, and communities.
A significant portion of important wetland areas are protected by the Service's National Wildlife Refuge System (NWRS), which consists of 570 individual system units across the United States, with the goal of conserving important habitat for the benefit of wildlife and citizens. Wetlands within the NWRS provide essential breeding, wintering, and stopover habitat for migratory birds and countless species of fish, mammals, and insects.
The Service's Migratory Bird Program is responsible for conserving migratory birds and their habitats. World Migratory Bird Day, which takes place on the second Saturday in May each year, celebrates the incredible journeys of migratory birds between their breeding grounds in North America and their wintering grounds in Mexico, Central America and South America. The event encourages bird conservation and increases awareness of birds through hikes, bird watching, information about birds and migration, public events, and a variety of other educational programs.
Federal Duck Stamps are a vital tool for wetland conservation. Since 1934, sales of the Duck Stamp to hunters, bird watchers, outdoor enthusiasts and collectors have raised more than $1 billion to conserve more than six million acres of habitat for birds and other wildlife and provide countless opportunities for hunting and other wildlife-oriented recreation on our public lands. Conservation of wetland habitat also supports numerous bird, mammal, fish, reptile and amphibian species that call wetlands home.
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