CW2: 3579

From Environmental Technology

Revision as of 21:20, 12 February 2006

Chesapeake Bay Ecosystem

a) What are wetlands? How are wetlands characterized? What are some types of wetlands?

Wetlands are the transitional link between the water and the land. Wetlands are characterized by hydrophytic vegetation (water-loving plants adapted to wet soils) and hydric soils (saturated or periodically flooded soils). There are two broad categories of wetlands in the Bay watershed. Wetlands within the reach of tides are considered tidal. Salinity in tidal wetlands ranges from fresh to saltwater. Nontidal or palustrine wetlands are freshwater areas unaffected by the tides. Scientists divide wetlands into two main groups: estuarine or palustrine wetlands. ‘Wetland’ refers collectively to marshes, swamps, bogs and similar areas found between dry land and water along the edges of streams, rivers, lakes, ponds, and coastlines.

b) What are the functions of wetlands?

Healthy wetlands remove and retain excessive nutrients, such as nitrogen and phosphorus, from the water. Forested riparian (or streamside) wetlands remove about 80 percent of the phosphorous and 90 percent of the nitrogen from water, which act as water contaminants and may result in unhealthy algae blooms. Wetlands also can minimize sediment loads and absorb chemical and organic pollutants before they can enter the Chesapeake Bay.

c) What is the percentage loss of Forest in the Bay area? How many tree and plant species are in the Bay area?

Forests once covered 95 percent of the watershed. Today, they cover about 60 percent, performing vital functions that benefit water and air quality. More than 50 major tree species and more than 2,700 different plant species grow in the Chesapeake Bay watershed.

d) What are the functions of the Forest?

Forests protect the water quality. Forests act as ‘sponges’ by capturing rainfall, reducing runoff, maintaining the flow of streams, filtering nutrients and sediment and stabilizing soils. They create a habitat for fish and wildlife. Healthy forests provide food, shelter, nesting sites and safe migration paths for the Chesapeake Bay’s aquatic and land animals. Forests also improve air quality. Forests absorb or trap nitrogen, particulates and other pollutants in the atmosphere that are released by cars, factories, farming and construction. Forests encourage recreation. Forests offer us places in which to reflect and experience natural beauty and solitude. They foster active outdoor recreation, such as fishing, hiking, camping and cross-country skiing. They also contribute to the economy. Forests produce wood for paper, building materials, fabrics such as rayon, and even food and medicines. The forest products industry is an important source of jobs for rural areas and small cities in the Bay watershed.

e) From the "Food Production & Consumption" section, list the types of trophs it discusses an categorize them.

Autotrophs are categorized as a producer, an organism that manufactures complex organic molecules from simple inorganic substances. Heterotrophs are categorized as a consumer, an organism that cannot synthesize its own food from inorganic materials and therfore must use the bodies of other organisms as sources of energy and body-building materials. Saprotrophs are categorized as a decomposer, a heterotroph that breaks down organic material and uses the decomposition products to supply it with energy.

f) What would happen to the entire system if the plankton were removed? Discuss the losses and problems that this could cause. Also, discuss what would happen if an unnatural overabundance of plankton were to occur in this region.

Phytoplankton can undergo rapid population growth or "algal blooms" when water temperatures rises in the presence of excess nutrients, which typically occurs each spring in the Chesapeake Bay.D uring these blooms, most of the phytoplankton die and sink to the bottom, where they decompose. This process depletes the bottom waters of dissolved oxygen, which is necessary for the survival of other organisms, including fish and crabs. If the plankton were removed, many organisms, including fish and crabs, would die because there wouldn't be anything to deplete the bottom waters of dissolved oxygen. While increased phytoplankton populations provide more food to organisms at higher trophic levels, too much phytoplankton can harm the overall health of the Chesapeake Bay.

g) Wetlands are disappearing from our coastlines at an alarming rate, does this sort of thing occur inland, or is it mainly a coastal problem? Is this really a problem, or should something be done about this? Have there been any other areas where deteriorating wetlands have caused other massive problems or do you think this is just a Chesapeake Bay problem?

This is also happening inland. Often viewed as wastelands, wetlands were drained or filled for farms, residential developments, commercial buildings, highways and roads. Over the past several decades, our understanding and appreciation of wetlands has increased. Plant diversity, biochemical reactions and hydrology of these habitats make them extremely productive. It is important to make sure something is done about this problem because many of the Bay's living resources depend on these wetland habitats for their survival. Tidal wetlands are the wintering homes for great flocks of migratory waterfowl. Other wildlife, including muskrats, beavers, otters, songbirds and wading birds, rely on wetlands for food and cover. Fish and shellfish, many of which are commercially valuable, use wetlands as spawning or nursery areas. Thousands of aquatic animals, including reptiles, amphibians, worms, insects, snails, mussels and tiny crustaceans, thrive in wetlands and are food for other organisms. Wetlands are also important for controlling flood and storm waters. Fast-moving water is slowed by vegetation and temporarily stored in wetlands. The gradual release of water reduces erosion and possible property damage. Coastal wetlands absorb the erosive energy of waves, further reducing erosion.