The Fragile Fringe: A Guide for Teaching About Coastal Wetlands

Introduction to the Fragile Fringe Teaching Guide

Wetlands are found throughout the United States and the world. Wetlands are transitional areas sandwiched between the inland and aquatic habitats. Indicative of the name, wetlands are land areas that tend to be wet or are regularly flooded and have a water table that is at or above the surface for at least part of the year. The names for these wetlands vary based on the geographical location; they may be identified as wet meadows, bogs, prairie potholes, bottomland hardwood forests, or freshwater marshes. Swamps are usually referred to as inland wetlands or lagoons, saltwater marshes, freshwater marshes, brackish and intermediate marshes, or mangrove swamps which are normally referred to as coastal wetlands.

In any wetland, the relationships between the plants and animals are very important. More attention is usually given to the animals in a wetland, but the role of the plants is a vital one. Naturally, the plants are a fundamental link in the food webs of a wetland; but they are also critical as shelter for young organisms, for structural stabilization, and for water retention in the system. Students should always be keenly aware of the connection between the plants and animals in a wetland since human activities which impact either plants or animals will inevitably affect the entire ecosystem.

Activities initiated by humans should not be the only concern of those interested in protecting and conserving the wetlands. Students should also consider the forces of nature and their effects on the wetlands. Hurricanes and flooding in recent years have shown just how fragile the coastal wetlands along the Gulf of Mexico are. Coastal wetlands and barrier islands, with their associated wetlands, serve to protect the inland areas by acting as buffers for major storms and hurricanes. Levees protect areas inhabited by humans in times of major flooding but at a high cost to the natural maintenance of the wetlands. Humans of all ages, in accepting the protection offered by wetlands, must also accept the responsibility of protecting the protector if this relationship is to continue.

Introductory Note

The intent of this material is to provide a basis from which a comprehensive study of coastal wetlands can be developed by the teacher on the basis of individual needs. Each teacher has students with varying needs and must, therefore, plan accordingly. The information and activities are provided as a framework and may be used and revised to accommodate different levels of students. Some activities may be used as demonstrations rather than student activities for younger students. Any grade level designation is only a suggestion; if it works for your students, use it.

For more information about wetlands, please explore the NWRC Web site at http://nwrc.gov. For more information about this teachers' guide, contact Mary Anne Townson at mary@dnr.state.la.us.

Background Information:

Listed below are several sources of basic background information:

Chabreck, R. H., and R. E. Condrey. 1981. Common vascular plants of the Louisiana marsh. Louisiana State University Center for Wetland Resources, Baton Rouge, LA. (Sea Grant Pub. # LSU-T-79-003)
Louisiana State Department of Education. Lafourche Parish Coastal Zone Curriculum Resource Unit: Bulletin 1834.
Weber, M., R. T. Townsend, and R. Bierce. 1992. Environmental quality in the Gulf of Mexico: a citizen's guide. Center for Marine Conservation, Washington, DC.

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Where Are the Wetlands?

Objective: To identify one or more types of wetlands

Many students will recognize the marshes along the coast as wetlands. Wetlands can be very large or very small and those along the coast are just a few examples of the types of the wetlands. Along with the freshwater, intermediate, brackish, and salt marshes of the coastal area, there are freshwater inland marshes, bottomland hardwood forests, edges of creeks, streams and ponds, and low elevation spots in fields that are considered to be wetlands. Lesser known wetlands may be the inland salt marshes of Utah and the Dakotas, the bogs in the northeastern and north-central United States, and the potholes of the northern Great Plains.

Activity: (for elementary - high school)

Look for a wetland closest to you. Check out the following possibilities on your school grounds, in your neighborhood, or within traveling distance of your school.
1. Along streams, creeks, ponds, bayous, or other permanent bodies of water
2. Temporary bodies of water that occur frequently and last for a week or more (check out the playground for a spot that stays wet after a rain, a vacant lot or field that always has a soggy spot - no buildings or crops because it is too wet)
3. An area close to the Gulf of Mexico - a chenier, a barrier island
Have the students walk around and observe the wetland(s) they find. Observations should include types of plants and animals, types of soil, smells, and sounds that may be different from those they have experienced in places they might not consider to be a wetland. In a wooded area, look for signs that water has been there although it may be dry when you are there. Look for water marks on trees, debris and leaves caught in bushes or trees above ground level, leaf litter that is soft due to absorption of water from the ground, or plant leaves covered with a film of mud or silt. (A skill that could be developed here is that of recording observations/data: journal entry, essay, photography, drawing/artistic skill.) Remember to have pictures in the classroom if the students can't go out. Having an assortment of pictures of the different types of wetlands is also a good resource.
Collect wetlands plants, then dry and press them. Remind students to record where and when they collected the plants for possible future reference.
1. Identify the plants using a plant identification guide (this can be done in the field without bringing the plants into the classroom). A good guide for wetland plants is Common Vascular Plants of the Louisiana Marsh (see resource list for complete bibliographic information).
2. Identify the types of leaves found (simple, compound) and the type of venation (for younger students, simply separate the leaves into groups by patterns of veins; older students can research and learn the terminology for venation: parallel, palmate, pinnate (view leaf venation diagram in the appendix). Note any differences in type of venation based on whether the leaves were collected from coastal or inland wetlands. Most marsh plants are grasses which have parallel venation; swamps have more woody vegetation which have pinnate and palmate venation.
3. For a creative activity have students use whole or pieces of the dried plants to create a picture or poster about wetlands.
Obtain a map of your area and/or the entire state. A regular map will do but a topographic map is best. (You may obtain topographic maps from local marinas or fishing tackle shops or order National Wetlands Inventory maps from USGS/ESIC, 507 National Center, Reston VA 22092 or call 1-888-ASK-USGS.) Have students find the wetland they located in exercise 1, if it is large enough. Look for other areas on the map that, based on the students' and your knowledge of wetland characteristics, might be a wetland (e.g., symbols for swamps are often found on common road maps). If using a topographic map, identify the methods used by cartographers of distinguishing different types of wetlands.
Extension (middle and high school):
Investigate prior records and maps to find out if there are areas that were once wetlands that are no longer classified as such. Investigate the reasons for this. Create maps showing differences in human habitation as wetlands have increased or decreased in an area.

Identify different types of wetland habitats using a key in the "Wetland Habitats" activity from WOW: The Wonders of Wetlands. (pp 21-23).

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The Mississippi River: Draining a Majority of the United States

Objectives:

To establish the role of the Mississippi River in the formation of the coastal wetlands
To increase awareness of the problems created by nature (flooding) and those from other sources (pollution) associated with the presence of the Mississippi River

The Mississippi River watershed drains a large portion of the land area between the Appalachian Mountains to the east and the Rocky Mountains to the west and carries that water and its contents through many states before discharging it into the Gulf of Mexico. Long before the Mississippi River was leveed, the sediments carried by the river were dispersed all along the coast of Louisiana as the river changed paths through time. This deposition of material in varying areas, called deltas, formed new areas of land and increased the health of the coastal marshes.

After the flood of 1927, the Corps of Engineers began building levees to contain the flood waters of the Mississippi. The Mississippi River, no longer able to change course, then began depositing all of its sediments into the deeper areas of the Gulf of Mexico where they are of no use to the coastal ecosystems.

Activity: (for upper elementary - middle school students)

Provide students with a map of the United States showing the Mississippi Drainage Area.
Mississippi Drainage Area Map
Have students label the rivers (or you may provide the names of the rivers on the map) and the states associated with the rivers. Some of the major rivers that feed the Mississippi River are the Ohio, Red, Platte, Missouri, Arkansas, Tennessee, and Yellowstone. Have students tally the number of states drained by the Mississippi Watershed.
Have students "build" the watershed in a pan using modeling clay or soil. Create indentions for the rivers and have them all connect into the "Mississippi" which in turn should empty into the "Gulf of Mexico."
Use small objects, beads or something similar, to represent things such as pollutants, litter, fertilizers, sediments, etc. that could be transported by the water flowing in the drainage system. Place the objects around the rivers and use a watering can to produce "rainfall" and "floods" that will transport the materials to the Gulf of Mexico.
1. Have students discuss the addition of these various materials into the waters of the Gulf of Mexico. How will they affect the animal life and plant life? What were the effects of sediments deposited in the past and what is happening to the sediments deposited now?
2. Use the activity "Deadly Waters" from the Aquatic Project Wild activity manual to introduce different kinds of pollution and their effects. (pp. 137-141).

Extensions (high school):

Research past floods, starting with 1993 and moving back in time, and explore the effects on commercial industries such as fishing, shrimping, and oystering in the Gulf of Mexico.
Pollutants added to the water in the rivers in this system are an obvious problem since this water will eventually travel through many states and enter the Gulf of Mexico. Have students explore uses of water taken from the river and how pollution might affect these uses. Introduce the idea of dilution of the pollutants by the water and let the students discuss/research the potential problems or reduction of problems associated with dilution.
Have students research and discuss ways that pollution added to rivers in various states has been reduced (if it has) by farmers, industry, and the shipping business. Distinguish between point and nonpoint source pollution and identify examples of each. Develop graphs and charts to show changes in pollution levels, if the information is available.

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Beneficial Functions of the Wetlands

Objectives:

To illustrate the value of the wetlands as a nursery for young organisms
To show the value of the wetlands in controlling erosion and retaining water
To demonstrate the role of the wetlands in absorbing/filtering pollutants and excess nutrients that would ultimately affect the Gulf of Mexico

The human view of the wetlands is, on occasion, focused too narrowly on the economic value of the area. There is no doubt about the economic value from commercial and recreational fishing, trapping for hides and furs, and tourism. Wetlands, however, have functions that are overlooked as a vital part of the ecosystem. Wetlands provide homes for juvenile organisms that need the protection of the grasses, more shallow water, and a sufficient food supply to grow into adults. They also provide temporary refuge for an extraordinary number of migrating birds. The structure of wetlands allows them to protect, in effect, the Gulf of Mexico as they absorb some of the pollutants and excess nutrient compounds that would otherwise drain off into the gulf and upset the chemical balance there. Because of wetland plants like Spartina (wiregrass and oystergrass) and their root systems, the flow of water across the area is slowed, which reduces erosion and enables the water to soak in and, under the appropriate conditions, supply surrounding aquifers with water. These fragile areas must be protected so they, in return, will continue to function as protectors of the coastal areas and wildlife.

Activities: (for elementary Students)

On a tile or wooden floor (the size of the floor area will be determined by the number of groups and the number of students in each group), drop 100 squares of paper, 1cm X 1cm, of several different colors. The different colors represent the various juvenile species (shrimp, red drum) that use the wetlands/estuaries for protection and feeding grounds until they are old enough to move into their adult habitat. The students are the predators of these juvenile organisms. The students can use their fingers (very young students) or forceps (older students) to remove the "organisms" from the wetland. Allow the students to pick up "organisms" ONE AT A TIME for 30 seconds. Count the number of organisms remaining in the wetland.

Cover the same area of the floor used above with a piece of deep-pile or shag carpet that has at least one of the colors of the paper used. This will represent the real wetlands with the plants that provide shelter and camouflage for the juvenile organisms. Repeat the same procedure with the squares and predator activity. The number of "organisms" surviving this time should increase since the "plants" provide protection from the predators and they are not as easily spotted.

Extensions: (upper elementary and middle school)
1. Continue the activity for several growing seasons and graph the numbers of organisms that survive.
2. Calculate the percent survival for each season and for the overall activity.
3. Make the activity more realistic by reducing the number of organisms each consecutive season by the percent of organisms that are eliminated by predators. This should show a drastic change in the scenario without protection for the juveniles.
4. Have the students do research on shrimp and red drum and produce food webs for the juveniles in the estuaries and the adults in the Gulf.
(for elementary - middle school students)
Demonstrate the change in the rate of flow of water and the amount of sediment carried when plants are introduced in a drainage pattern. Cover the bottom of a large baking pan (deep enough to contain enough soil to "plant" vegetation) with a two inches of soil. Tilt the pan and pour a given quantity of water (a quart to a gallon depending on the size of the pan) onto the soil (a watering can will simulate rainfall; pouring water directly from a bottle will simulate stream flow and will increase sediment transport). Try to empty the container of water in the same amount of time for each trial.

Measure the amount of time with a stopwatch (or second hand of a clock) it takes the water to get from the top of the pan to the bottom. Catch overflow in a dishpan. Using a relatively small diameter container, collect the overflow and water that reached the bottom of the pan and let it settle. Record the amount of water that reached the bottom (a mark on the container will be sufficient if you do not have a beaker) and the amount of sediment that settles out of the water.

You can measure the depth of the sediment if you use the same container to catch the water on the next trial since the diameter of the container will be the same. (If you have access to an Imhoff Settling Cone, you can read the amount of sediment directly but this is not necessary) Repeat the same process but "plant" some vegetation in the soil (you can use weeds that you pull up out of the school grounds - include the roots for a more realistic situation). Put as many plants in the soil as you can since an effective wetland would contain a high concentration of plant life. For this trial, the water should take longer to get to the bottom of the pan, less water should make it to the bottom, and there should be less sediment than with the first trial. (NOTE: this is a simple exercise for introducing the concepts of controls and experimental groups in scientific investigations.)
Have students discuss reasons for the following:
1. Why was there less runoff when the plants were in the "wetland"? Discuss the "sponge" capabilities of the coastal marshes.
2. Why was the time different for the second trial?
3. Why was there a difference in the amount of sediment deposited in the two trials? How is this important to the wetlands?
Extensions: (middle - high school students)
1. Investigate and set up an experiment to demonstrate a wetland's capabilities of reducing the amount of pollution entering the Gulf of Mexico. Suggestion: Use a plastic flower plot with drain holes in the bottom to allow you to catch the water draining through. Fill the pot with soil. Mix water (about a quart) and diatomaceous earth (this will become suspended but not dissolve) and pour this over the soil. Collect the water that drains through and compare it to what you poured in. This will show the reduction of materials draining out of the wetland into the nearest body of water.
2. Runoff from farming communities poses a problem to streams, rivers, bayous, and even the Gulf of Mexico because it contains excess nitrogen and phosphorous compounds that change the amounts of aquatic vegetation. Research the effects of these compounds (primarily from fertilizers) on the plant and animal life in water bodies. Find recent examples of these occurrences in wetland areas.
3. Use the information in #2 to describe the effects of contaminants on a food web in a stream or bayou. What influence could this have on the juvenile organisms living in the estuaries? Discuss any effects on the fishing and/or shrimping industries.
4. (for physical science and physics students) Discuss the carrying capacity of water as related to velocity. Find historical examples of destruction by fast-moving flood waters.
(for elementary students)
Demonstrate the concept of how a water table works and a wetland's ability to replenish aquifers. Older students can work in small groups and perform the activity on their own.

Use a large baking dish or dishpan (at least 10" X 13") for this activity (Fig. 1). Place a large sponge in one end of the pan to represent a wetland. Add enough sand to the rest of the pan to make a level landscape. Add water to the pan so that the sponge is completely saturated and the sand is saturated but not covered with water.

First, scoop out a spoonful of sand (to a depth below the water table) and let the students observe the filling in of the hole. Discuss the water table. Make a stream several inches away from the wetland by making an indention into the sand from one side of the pan to the other. To demonstrate the wetland's ability to replenish lost water, use a dry sponge and soak up the water IN the stream. Have the students observe the resulting water movement. The sponge or wetland is going to give up its water as the water in the sand moves into the "dried up" stream.
Extensions: (for middle - high school)
1. Have students relate the movement of water to changes in concentration and flow between areas of high and low concentrations and identify the laws that govern these physical principles.
2. Have students research pollution and water tables. Identify historical examples of delayed problems with water sources related to pollution.

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Barrier Islands as Part of and Protection for the Wetlands

Objectives:

To identify the barrier islands as part of the wetlands
To show the value of the barrier islands to the wetlands

Although barrier islands, called spits in the northeastern United States, exist on all coastlines, they are most notable along the Gulf of Mexico and Atlantic coasts. They are the structures resulting from the movement of sediments by wind and the currents. The seaward side of a barrier island is usually a sandy, beach-like area (Fig. 2). This area increases and decreases in size with changes in seasonal wind and wave action which carries sand into and away from the sandy shore.

Figure 2

The area behind the beach is an area of dunes and then a mud flat or over-wash area created when the waves breach a low area of a dune (Fig. 3). The dunes contain plants that stabilize the system by trapping sand that would otherwise be blown away. The flat is wet and may be completely flooded during storm surges and extremely high tides. Beyond the flat is a salt marsh. These islands, as obstacles, slow down the waves and winds associated with strong storms and hurricanes that impact the coastal areas. They also provide a habitat for a many of the same species found along the coastal marshes.

Aerial View of Over Wash on a Barrier Island

Figure 3

Activity: (for elementary students)

Line students up on one side of the classroom (Fig. 4). They will represent an incoming wave or strong wind. Have them move as a group across the room and record the time it takes for them to cross the room. Next, set up a barrier of cardboard boxes, chairs, cement blocks, or boards (anything that is available and not dangerous to the students). This time, they must cross the room and go across the barrier. Record the time it takes for them to travel the same distance.

Discuss why it took them longer to cross the room the second time and how this phenomenon can positively affect the coastal wetlands. Ask the students about the type of organisms, plants in particular, that must inhabit the barrier islands. This might include ideas about how they are anchored so that they can withstand the wind and wave action as well as the fact that they are relatively small and shrubby.

Diagram showing student paths across an empty room and with a barrier

Figure 4

Extensions: (for upper elementary and middle school students)

Have students research and set up a demonstration to show why waves "break" as they reach the shore.
Let the students find out why dunes with plants on them are generally larger than those without plants (give them a hint about carrying capacity of the wind at different speeds, if they need help). They may also research the formation of the barrier islands - explain why the sand was deposited there to begin with as well as how barrier islands "move."

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Loss of Wetlands: Subsidence

Objectives:

To define subsidence and demonstrate the resulting effects on wetlands
To introduce global warming and sea-level rise as factors in wetland loss

Subsidence in the coastal marshes involves two factors: the sinking of the marsh surface and a lack of sediment being added to the marsh surface. As materials in the marsh settle, decay, and compact, the marsh effectively sinks a little. If new sediments are not being added to the system, the entire system is going to decline in elevation. Water will now pool in these lower elevation spots when there is a very high tide.

As the temperature of the earth increases little by little (global warming) and the sea level begins to rise, these areas become permanently flooded, the marsh is lost, and more open water areas result. To some degree leveeing and channelization have impacted this sinking and building up of the marshes because they reduce the amount of sediment available for vertical marsh buildup. A healthy marsh system with adequate amounts of vegetation will tend to trap whatever sediment is available and promote vertical buildup.

Activities: (for elementary and middle school students)

Fill 2/3 of one end of a large glass dish or clear plastic box with loosely packed soil. Let the students mark the level on the side of the container. Using a watering can or spray nozzle, drench the soil (use a ruler or board to keep the soil from being washed into the other end of the container) and let the students observe the difference in "elevation" of the soil. Explain that in a marsh, the air in the soil is always being replaced by water (the percolation process) and the soil settles or subsides.

Materials decay quickly under moist conditions, so this also reduces the amount of organic material in the soil. Ask the students for suggestions as to what would be needed to keep the elevation constant. Ask how building levees along rivers has hindered sediment addition to the wetlands. Water used to drench the soil should have run off into the empty 1/3 of the pan. Have students mark the level of the water on the "shore" (use a toothpick or small stick).

Add additional water to this to simulate sea level rise. Have the students mark the new "sea level" after the addition of the water. If the pan is large enough, create a large wave. If there are any depressions that formed during the settling of the soil, ask the students what happens to them after the wave recedes. Have the students speculate about what will happen to this newly formed pond.
Extension: (for middle school students)
Let the students set up the experiment with the soil except that the soil should be 4 -6" deep. It can be in a large plastic tub or on the ground outside. (The water next to the soil is not necessary for this step.) Have the students decide where they are going to dig a canal. Have them place several strips of paper vertically from the edge of the site of the canal out towards open land. As they dig the canal, they should place the spoil (dirt dug from the canal) right along the edge of the canal they are digging. As they pile the spoil up along the bank, they should notice that the soil in this area is sinking - the end of the paper along the bank begins to settle lower than the other end. Ask the students to discuss the effect of dredging and canal building on subsidence.
(for upper elementary - middle school students)
Subsidence can also be related to the removal of subsurface materials such as gas and oil. Use a gallon milk jug (Fig. 5) with the top cut off and a small hole (large enough for the tip of a balloon to fit through) about 2" above the bottom of the jug. Fill the bottom 2" of the container with soil, partially blow up a balloon (blow it up only enough that it can be flattened out to about 2" as you pile dirt on top of it), and pull the end of it through the hole in the side of the milk jug, and pile 2-4" inches of dirt on top of the balloon.

The air in the balloon will represent a natural gas/oil deposit under the surface. Mark the level of the top of the dirt on the milk jug. Let the air out of the balloon either by cutting the end off or sticking a sharp object through the hole into the balloon. Mark the resulting level of the dirt. Have students suggest possible effects on the coastal regions of the state since oil and gas exploration and removal began in the early 1900's.
(for middle school students)
Use a mixture of clay, sand, silt, and peat in an aquarium (or other large clear container). Add water to demonstrate the percolation, settling, and compaction of soils in the marsh resulting in subsidence (see note about the mixture to use). Have students watch the mixture after the water has been added and record any changes they see taking place in the mixture. How does the settling occur? Is there a pattern or is it a random process?

To illustrate the possible formation of sinkholes associated with the removal of underground materials such as gas and oil, inflate a balloon and put it under the soil mixture. After the mixture has settled and dried for several days, insert a probe or long skewer and puncture the balloon. Have the students record what happens.

Ask the students to research the occurrence of sinkholes in the United States. With what kinds of geologic structures were these sinkholes associated? Were gas and oil explorations underway in the immediate area?

Note: A ratio (by weight) of 35% sand, 30% silt, 30% clay, and 5% organics (peat) can be used to "produce" a marsh mixture. A note of caution: care should be taken to avoid inhaling the mixture over prolonged periods since some of the components are very small and easily become airborne during mixing.

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Wetland Loss: Digging of Canals

Objective: To illustrate the destruction of wetlands that resulted from the digging of canals for oil and gas exploration in the coastal wetlands and cypress logging in the swamps.

The small canals and channels naturally occurring in the marsh were perfect for small boats and canoes used by hunters, trappers, and fishermen. With the advent of oil and gas explorations in the marshes and cypress logging in the swamps around the Lake Maurepas/Lake Pontchartrain area, deeper and wider channels were needed for larger boats. The channels did not meander like many of the natural ones; they were dug straight and deep. The spoil was piled on the banks which smothered and destroyed any vegetation that would stabilize the bank structure. The spoil also set up barriers to the natural flow of water across the wetland, resulting in the flooding of many areas.

The increased boat traffic produced greater wave action against the banks. The faster velocity of the water moving in a deeper, wider channel, and the decreased quantity of plant roots along the banks resulted in the widening of the channels and the loss of wetlands. Currently, the use of existing channels is encouraged rather than the construction of new channels to access areas of the marshes or swamps. This practice cannot return the lost acres, but it can prevent further destruction of the fragile areas that remain.

Activity: (for elementary - middle school students)

Have 2 groups of students fill a large pan or dishpan half full of soil. Each group will create a canal, piling the spoil on each side of the canal as it is dug -one group will dig the canal horizontal to the direction of flow of the water and the other group will dig the canal vertical to the flow of water (Fig. 6).

Figure 6

Have the students observe and record the results of water flow representing rainfall, flooding, and high tides using a watering can, water hose or bottle of water to simulate different phenomena. What are the effects of excess water pooling in the wetland? Would it have been possible to dig the canals in such a way as to avoid the destruction of the wetlands?

Extension: (for middle - high school students)

Have the students examine topographic maps of the area in which they live to identify natural and constructed canals in the wetlands. If possible, find older maps and compare the area of wetlands before and after major canals were built.
Have the students research the relationship between channel building, subsidence and salt-water intrusion, and wetland loss in both fresh and saltwater wetlands across the United States.

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Glossary

AQUIFER: an underground layer of rock and sand that contains water
BARRIER ISLAND: long, narrow strips of sand forming islands that protect inland areas from ocean waves and storms
BOTTOMLAND HARDWOOD FORESTS: forested, periodically flooded wetlands found along rivers
BRACKISH MARSH: marshes occurring where salinity ranges from 3-15 parts per thousand (ppt); dominated by Spartina patens (wiregrass)
CARNIVORE: any organism that eats other consumers (sometimes referred to as "meat eaters")
CHENIER: a ridge formed by the lateral transport and reworking of deltaic sediments, usually containing large amounts of shell deposits; named for the oak trees (chene -French for oak) found growing on the ridges
COMPOUND LEAF: a leaf composed of multiple leaflets; note that leaflets do NOT have an axillary bud at their base (view leaf pattern diagram)
CONSUMER: any organism that cannot produce its own food and must, therefore, get its energy by eating, or consuming, other organisms
DECOMPOSER: organisms such as fungi and bacteria that feed on dead material causing the chemical breakdown of the material
DELTA: an area formed from the deposition of sediments at the mouth of a river
DETRITIVORE: any organism that consumes detritus
DETRITUS: dead, decaying plant material
DREDGING: the removal of sediment from a channel to produce sufficient depths for navigation
DUNE: a low hill of drifted sand in coastal areas that can be bare or covered with vegetation
ESTUARY: an environment where terrestrial, freshwater, and seawater (saline) habitats overlap
FOOD CHAIN: transfer of food energy from plants to one or more animals; a series of plants and animals linked by their food relationships
FOOD WEB: a series of linked food chains
FRESHWATER MARSH: grassy wetlands that occur along rivers and lakes; dominated by grasses, reeds, rushes, and sedges
GLOBAL WARMING: an increase of the earth's temperature by a few degrees resulting in an increase in the volume of water which contributes to sea-level rise
HERBIVORE: any organism that eats only producers (plants)
INTERMEDIATE MARSH: a marsh occurring where the salinity is about 3 parts per thousand (ppt) - a transitional area between fresh and brackish marshes; common plants are bull tongue, roseau cane, and wiregrass
MARSH: an environment where terrestrial and aquatic habitats overlap; a wetland dominated by grasses
MUDFLAT: a muddy, low-lying strip of ground usually submerged, more or less completely, by the rise of the tide; found in association with barrier islands and cheniers along the gulf coast
NONPOINT SOURCE POLLUTION: indirect or scattered sources of pollution that enter a water system such as drainage or runoff from agricultural fields, airborne pollution from cropdusting, runoff from urban areas (construction sites, etc.)
OMNIVORE: any organism that eats both plants and animals
PALMATE VENATION: vein arrangement with veins radiating outward from the base of the leaf like fingers spread out from the palm of the hand (view leaf venation diagram)
PARALLEL VENATION: vein arrangement with veins parallel from the base to the tip of the leaf (view leaf venation diagram)
PINNATE VENATION: vein arrangement with one main vein extending from the base to the tip of the leaf and smaller veins branching off the main vein (view leaf venation diagram)
POINT SOURCE POLLUTION
ppt: parts per thousand - a unit used to indicate salinity
PREDATOR: an animal that lives by capturing other animals for food
PREY: an animal that is killed and eaten by another animal
PRODUCER: any organism that is capable of producing its own food, usually through photosynthesis
SALTWATER INTRUSION: the invasion of freshwater bodies by denser salt water
SALTWATER MARSH: saltwater (15-18 parts per thousand or greater) wetlands occurring along the coast; dominated by saltwater grasses such as Spartina alterniflora (oyster grass)
SCAVENGER: an animal that eats the dead remains and wastes of other animals and plants
SEA-LEVEL RISE: a rise in the surface of the sea due to increased water volume of the ocean and/or sinking of the land
SIMPLE LEAF: a leaf composed of a single blade (view leaf pattern diagram)
SPOIL: the material removed from channels and canals by dredging
SUBSIDENCE: a gradual sinking of land with respect to its previous level
SWAMP: forested low, spongy land generally saturated with water and covered with trees and aquatic vegetation; may be a deepwater swamp, such as the cypress tupelo, which has standing water all or part of the growing season or bottomland hardwood forests which are only flooded periodically
TOPOGRAPHIC MAP: a line and symbol representation of natural and artificially created features in an area
WATERSHED: an area drained by a river
WETLANDS: land areas that are wet due to a close relationship to a body of water or groundwater, or land areas that are flooded regularly; they support vegetation adapted for life in saturated soil conditions

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References

Abrams, E., and L. Soniat. Wetland activities - food chain, food web, energy flow. Louisiana Department of Wildlife and Fisheries and Louisiana Sea Grant College Program, Baton Rouge, LA. 14 pp.

Aquatic Project Wild. 1987. Western Regional Environmental Education Council. 240 pp.

The coastal zone: activities for the classroom. 1991. Louisiana Universities Marine Consortium, Chauvin, LA, and Louisiana State Department of Natural Resources, Raton Rouge, LA.

Lindstedt, D. M. 1990. Coastal resource unit for middle school teachers. Louisiana Department of Natural Resources, Baton Rouge, LA.

Louisiana Land and Exploration Company. 1989. Loss of Louisiana Wetlands. New Orleans, LA.

Main, A. C., and R. H. Mills. 1991. Leaf key to common trees in Louisiana. Louisiana Cooperative Extension Service, Louisiana State University Agricultural Center, Baton Rouge, LA.

Penn, G. 1992. Marine awareness. Southwest Fisheries Center, Tiburon Laboratory; National Marine Fisheries Service; National Oceanic and Atmospheric Administration; U.S. Department of Commerce.

Sikora, J. P., ed. Lafourche Parish coastal zone curriculum resource unit. Bulletin 1834. Louisiana State Department of Education, Baton Rouge, LA.

Slattery, B. E. 1991. WOW: The Wonders of Wetlands. Environmental Concern, Inc., St. Michaels, MD.

This is coastal Louisiana. 1993. Louisiana State Department of Natural Resources, Baton Rouge, LA.

Watzin, M. C., and J. G. Gosselink. 1992. The fragile fringe: coastal wetlands of the continental United States. Louisiana Sea Grant College Program, Louisiana State University, Baton Rouge, LA; U.S. Fish and Wildlife Service, Washington, DC; and National Oceanic and Atmospheric Administration, Rockville, MD.

Weber, M., R. T. Townsend, and R. Bierce. 1992. Environmental quality in the Gulf of Mexico: a citizen's guide. Center for Marine Conservation, Washington, DC.

Wells, J. T., and C. H. Peterson. Restless ribbons of sand: Atlantic & gulf coastal barriers. Louisiana Sea Grant College Program, Louisiana State University, Baton Rouge, LA, and U.S. Fish and Wildlife Service, National Wetlands Research Center, Slidell, LA.

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Resources for Information and Activities

Abrams, E., and L. Soniat. 1992. Wetland activities - food chain, food web, energy flow. Louisiana Department of Wildlife and Fisheries and Louisiana Sea Grant College Program, Baton Rouge, LA. 14 pp.

America's endangered wetlands. 1990. Department of the Interior; U.S. Fish and Wildlife Service. (brochure)

Aquatic Project Wild. 1987. Western Regional Environmental Education Council. 240 pp.

Chabreck, R. H., and R. E. Condry. 1981. Common vascular plants of the Louisiana marshes. Louisiana State University Center for Wetland Resources, Baton Rouge, LA. (Sea Grant Publication # LSU-T-79-003)

Coast & Sea. Write to Coast & Sea, Louisiana Sea Grant Communications Office, Louisiana State University, Baton Rouge, LA 70803. (504) 388-6448. (Subscriptions are free upon request.)

The coastal zone: activities for the classroom. 1991. Louisiana Universities Marine Consortium, Chauvin, LA, and the Louisiana State Department of Natural Resources, Baton Rouge, LA.

Environmental science. 1987. Calcasieu Parish Schools. Lake Charles, LA.

Living in water. 1987. An aquatic science curriculum for grades 4-6. National Aquarium in Baltimore.

Louisiana Land and Exploration Company 1989. Loss of Louisiana Wetlands. New Orleans, LA.

Madrazo, Jr., G. M., and P. Hounshell, ed. 1990. Oceanography for landlocked classrooms. National Association of Biology Teachers, Reston, VA.

Main, A. C., and R. H. Mills. 1991. Leaf key to common trees in Louisiana. Louisiana Cooperative Extension Service, Louisiana State University Agricultural Center, Baton Rouge, LA.

Our Gulf of Mexico: handle with care. Louisiana Universities Marine Consortium; Lafayette Natural History Museum; Louisiana Nature and Science Center, New Orleans, LA.

Penn, G. 1992. Marine awareness. Southwest Fisheries Center, Tiburon Laboratory; National Marine Fisheries Service; National Oceanic and Atmospheric Administration; U.S. Department of Commerce.

Project earth: activity handbook for teachers. 1991. Capitol Soil and Water Conservation District, Denham Springs, LA.

Project Learning Tree. 1988. The American Forest Council.

Project Wild. 1986. Western Regional Environmental Education Council.

Sikora, J. D., ed. Lafourche Parish coastal zone curriculum resource unit. Bulletin 1834. Louisiana State Department of Education, Baton Rouge, LA.

Slattery, B. E. 1991. WOW: The Wonders of Wetlands. Environmental Concern, Inc., St. Michaels, MD.

Watzin, M. C., and J. G. Gosselink. 1992. The fragile fringe: coastal wetlands of the continental United States. Louisiana Sea Grant College Program, Louisiana State University, Baton Rouge, LA; U. S. Fish and Wildlife Service, Washington, DC; and National Oceanic and Atmospheric Administration, Rockville, MD.

Weber, M., R. T. Townsend, and R. Bierce. 1992. Environmental quality in the Gulf of Mexico: a citizen's guide. Center for Marine Conservation, Washington, DC.

Wetland Journal: Research, Restoration, Education. Quarterly publication of Environmental Concern, Inc., P.O. Box P, 210 West Chew Avenue, St. Michaels, MD 21663. (410) 745-9620.

Addresses and Phone Numbers:

Barataria-Terrebonne National Estuary Program
Nicholls State University Campus
P. O. Box 2663, Thibodeaux, LA 70310
(504) 447-0868 or 1-800-259-0869
(Free video -"Haunted Waters, Fragile Lands, Oh What Tales to Tell!" - and information upon request)

U. S. Fish and Wildlife Service
Richard B. Russell
Federal Building, Room 1200
75 Spring St. SW
Atlanta, GA 30303

Louisiana Cooperative Extension Service
Louisiana State University
Agricultural Center
Baton Rouge, LA. 70803
(Only requests for small amounts of material at a time are honored.)

Gulf of Mexico Program Office
John G. Stennis Space Center
Building 1103, Room 202
Stennis Space Center, MS 39529-6000
(601) 688-3726

Human Resources Officer
U.S. Fish and Wildlife Service
Department of the Interior
4401 N. Fairfax Drive, 300 WEBB
Arlington, VA 22203
(703) 358-1724

Earth Science Information Center
U.S. Geological Survey
507 National Center
Reston, VA 22092
(703) 648-6045 or 1-888-ASK-USGS

National Water Information Clearinghouse
U.S. Geological Survey
423 National Center
Reston, VA 22092
(703) 648-6803

U.S. Environmental Protection Agency
1-800-832-7828

Bureau of Land Management
Office of Environmental Education
Code 111
1849 C Street NW
Washington, DC 20240
(202) 452-5078

Education Specialist
National Park Service
Division of Interpretation
P. O. Box 37127
Washington, DC 20013-7127
(202) 523-5270

Human Resources Office
Education Specialist
Bureau of Reclamation
P. O. Box 25007
Denver Federal Center
Denver, CO 80225
(303) 236-8633

Louisiana Energy and Environmental Resource and Information Center (LEERIC)
1-800-256-ERIC or (504) 388-4600

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The Fragile Fringe: A Guide for Teaching About Coastal Wetlands

Introduction to the Fragile Fringe Teaching Guide

Where Are the Wetlands?

The Mississippi River: Draining a Majority of the United States

Beneficial Functions of the Wetlands

Barrier Islands as Part of and Protection for the Wetlands

Loss of Wetlands: Subsidence

Activities: (for elementary and middle school students)

Wetland Loss: Digging of Canals

Activity: (for elementary - middle school students)

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Resources for Information and Activities

Further Reading List

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