Georgia 4-H Agriscience

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					                                       Georgia 4-H Agriscience
                                         Pilot Lesson Plan

                                        Title of the Lesson:
                                       Georgia Barrier Islands

                      Submitted by: Zona Medley & Melanie Briersmith
                      Edited by: Mandy Marable and Lori Purcell
                      County: Colquitt and Jekyll Island 4-H Center

Contact Information:
Zona Medley
Veteran’s Parkway North
350 Bldg. 1, Room 132
Moultrie, GA 31788
Phone: (229) 616-7455; Fax: (229) 616-7033;

Melanie Briersmith
Jekyll Island 4-H Center,
201 S. Beachview Drive
Jekyll Island, GA 31527
Phone: (912) 635-4117; Fax: (912) 635-4135

Estimated Time: 30-40 Minutes

Description/Lesson Overview: In this lesson students will examine the
dynamics of barrier islands and locate the barrier islands. Causes of erosion will
be discussed through examination of the current state of Jekyll Island.

Goal: Exploration of Georgia’s barrier islands with emphasis on Jekyll Island and
the consequences of beach erosion.

Students will identify surface features of the Earth caused by constructive and
destructive processes.

GA 4-H Core Value: Environment

The learner will:
 define barrier islands
 locate Georgia’s barrier islands on a map
 describe the processes of erosion and accretion
 describe the formation of sand dunes
 explain the importance of sand dunes
 identify sea oats and explain their importance

     2 Trays for sand dunes
     Sand
     Spray bottle of water
     Personal battery operated mini fan
     Pictures of dunes and sea oats
     Poster of Jekyll Island
     “A Changing Coastline” worksheets from The Water Sourcebook p. 530
     Observation worksheets

     Prepare a sand box to demonstrate the effects of wind and water erosion
      on an area of the beach.



1. Accretion: building up of land by physical forces
2. Barrier Island: long, narrow island lying parallel to the
   mainland and separated from it by bay, lagoon, or marsh
3. Continental Shelf: remaining submerged portion of the
   coastal plain
4. Erosion: process of being gradually worn away
5. Longshore Current: current that runs parallel to the
   shore within the surf zones
6. Marsh wrack: windrows of dead cordgrass from the
   marsh left behind on the beach by the wave wash.
7 Sea oats: a tall grass (Uniola panicolata) that grows on
   the coast of the southern United States and helps hold
   sand dunes together
8 Sand dunes: a hill of sand piled up by the wind

 Begin by asking students; how many of you enjoy the beach? (Wait for
 responses.) I enjoy the beach too. As a matter of fact, I really like Jekyll Island.
 Not only because we have a great 4-H Center there, but also because it is a
 great place to enjoy the beach. Did you know there is something very special
 about Jekyll Island? Can anyone tell me why Jekyll Island is so special? (Allow
 time for responses.) Jekyll Island is a Barrier Island and that is why it is
 unique. What is a barrier island? A barrier island is a long, narrow strip of land
 that lies parallel to the mainland. It is separated from the mainland by a bay, a
 lagoon or a marsh. Barrier islands, which border the U.S. Atlantic and Gulf
 coasts, protect the mainland from the damaging effects of wind and waves. In
 addition to Jekyll, Georgia has 7 other major barrier islands. (Display Georgia
 map.) Let’s see how many you can name and locate? Since we have already

identified Jekyll, we will locate it on our map first. (1. Call on students to name
an island and place the name cards on the correct island. 2. Ask for
volunteers to come and place the island name cards correctly on the map.)
Tybee, Skidaway, Wassaw, Sapelo, Little Saint Simons, Saint Simons,
Cumberland. Great job!

(Display poster of Jekyll Island) Today, we are going to focus on Jekyll Island
because of the amount of beach erosion that is happening there. What is
erosion? (Listen to responses and restate the definition of erosion from the
vocabulary list.) Erosion is the process of being gradually worn away. Why
should we be worried about the beaches eroding? (Listen to responses and
reply accordingly.) What factors are causing the erosion process on Jekyll
Island? Waves, wind, currents and on Jekyll the shipping channel adds to this
situation. Jekyll Island is the smallest island in the eight major island clusters
along the coast of Georgia. It is only 7.5 miles long and 2.3 miles across at the
widest point. Jekyll Island covers 5700 acres, but 1400 of those acres are
marshland. The erosion of the beach from parts of Jekyll Island is a great
concern to many residents and environmentalist.

Development of Concepts/Core: (Experience-Share)

Before we begin learning about the erosion process, you may be wondering
where the sand on the beach came from. The sands of barrier islands come from
the weathering of the Piedmont and the Appalachian Mountains. Here again, we
must remember the definition of erosion. In Georgia, sands coming from
mountains are deposited in the slow, meandering streams of the lower Piedmont
and Coastal Plain and very little ever reach the coast. Most sand on the beach
comes from the continental shelf and is pushed up by the waves. The continental
shelf is the remaining submerged or under water portion of the coastal plain. As
waves travel across the continental shelf, they pick up grains of sand and bring
them to the shore.

Although the same forces – wind, waves, and currents – affect all barrier islands,
each island is an individual unit. Let’s talk about the different forces that affect
Jekyll Island. (Jekyll poster for this information)

The first is the Longshore Current.
Sand on the beach is constantly shifting and migrating due to the physical forces
of wind, waves, and currents. Winds, waves, and currents determine the
direction and rate of sand transport. The longshore current is a current in the
water that runs parallel to the shore within the surf zones. During most of the
year, winds from the northeast generate waves which hit the beach at an angle.
These small, low-energy waves generate the longshore current which transports
sand along the beaches in a north to south direction. The transported sand is
usually deposited on the south end of the island in the process of accretion. Who
can tell me what I mean by accretion? Accretion is the building up of land by
physical forces. (Use the map to illustrate this point. Show the difference in
the size of the north end of the island compared to the south end.) The

longshore current is a strong flowing current that transports large amounts of
sand in shallow waters.

Who can tell me what other force plays a part on changing the shape of
beaches? (Allow time for discussion.) Waves play a big part. Most of the sand-
moving work is done by intense storms that come a few times a year. When a
wave breaks on the shore, most of the energy is spread out along the shoreline
and the wave drops its load of particles. Waves constantly moving sand onto the
beach results in re-distribution of the sand. From late spring through early fall,
Georgia gets soft southeasterly and easterly winds, the seas are calm, waves are
gentle, and storms infrequent. The transport of sand is toward the shore and
sand is deposited high on the beach making for a broader and flatter beach.
During the winter when northeast storms bring higher winds and steeper waves,
higher wave energy removes sand from the beach resulting in a narrower,
steeper beach.

Now that we know something about the causes of erosion of beaches, let’s
discover how the island protects its self naturally. What element is located on the
beach to protect the island? (Listen for answers. Give clues to encourage
discussion.) We all know that a sand dune is a hill of sand piled up by the wind.
(Display picture of dunes.)

Sand dunes protect the island from wind and waves, provide natural beach
stability, and a supply of sand for the changing beach, as well as habitat for
plants and animals. Sand dunes begin with marsh wrack. Have you ever been
to the beach and there were dark dirty looking lines in the sand? That was
marsh wrack. Marsh wrack is simply dead cordgrass from the marsh that is left
behind on the beach by the waves. The marsh wrack becomes a mesh that traps
wind-blown sand and seeds. Because of this, the marsh wrack plays a vital role
in forming new sand dunes. Plants stabilize dunes as sand continues to
accumulate. Support for the dune comes from the root network and shoots of
sea oats and other dune plants. Sea oats are a tall grass (Uniola panicolata) that
grows on the coast of the southern United States and helps hold sand dunes
together. Sea oats are highly adapted to the dune environment. Their long curly
leaves and tall oat heads trap windblown sand which quickly causes them to
become buried. (This could be sketched on the board to assist the visual
learner.) By growing vertical runners, which produce daughter plants on the
surface of the growing dune, sea oats stay ahead of the accumulating sand while
most other plants become buried and die. Sea oats are master dune builders.
Because of their vital role in building and stabilizing dunes, sea oats are
protected by law; there is a very stiff fine for picking or damaging the plants.

Erosion is a major force that affects the barrier islands. This is a process which
typically occurs at the northern end of the island. On Jekyll, that process has
increased due to the shipping channel which blocks any supply of new sand from
coming in.

The beach represents one of the most dynamic environments on earth. As we
have learned the condition of the beach system depends on three elements:
wave energy, wind, and sand supply. The complex interaction and balance
among these elements determines the shape of the beach and its position.

(Provide students the observation worksheets.) I have two different beach
environments. (Display trays.) One beach has sand dunes formed and the other
does not. We are going to use this spray bottle of water and my mini fan to
represent wind and water. This will emulate the erosion process. I want you to
record you observations. (Simultaneously, have one student spray the water
and another hold the fan for 60 seconds on each tray of sand. After the
experiment, have students share their findings from their observations

The experiment we just conducted happens everyday on our beaches and
barrier islands in America.

Wrap Up/Review/Reflection :( Process-Generalize-Apply)

Now that we have studied the changing shape of the Jekyll coastline, what forces
can change the shape of other barrier islands? Who is affected by erosion?
Look at the two illustrations on the handout. (A Changing Coastline.) Can you
explain the difference in the two pictures? Is this an example of erosion or

What could be added to the coastline to prevent more erosion from happening?


1.    a) Describe how dunes form.
      b) Why are dunes important?
      c) What holds dunes together?
2.    a) Which end of barrier islands tend to erode?
      b) Which end of barrier islands tend to accrete?
3.    a) Which direction does a longshore current run?
      b) Does the long shore current move sand from the
4.    a) Define erosion.
      b) Define accretion.

Useful Resources:

1. Marine Education Center & Aquarium
   Natural History of the Georgia Coast
2. Sherpa Guides
   The Natural Georgia Series: Barrier Islands
3. The Water Wise Curriculum – A changing Coastline p. 530

Name: ____________________             Georgia 4-H Agriscience
Date: ____________________             Barrier Island Observation Sheet

Record your observations.

Possible effects to look for:

   1.     What effects does the wind have on the beach without the sand

   2.     What effects does the water have on the beach without the sand
          dunes? On the beach with the sand dunes?

   3.     How do the sea oats affect the beach environment?

   4.     What other observations can you see?