Food Webs of the Ogeechee River

Background Information: The Ogeechee River is a 245 miles long black-water river. It begins with spring-fed streams 650 feet above sea level in Green County, Georgia and increases in volume as it flows south, through the Piedmont to the fall line. As the river flows over the fall line, it enters the Upper then Lower Coastal Plain where it increases in volume, depth, and width. Below Millen, GA, the river cuts through sand and clay bluffs which provide dry areas for boaters, fishermen, and picnickers to camp. The Ogeechee River is joined by the Canoochee River northwest of Savannah, and then meanders through salt marsh until it enters the Atlantic Ocean.

The Ogeechee River provides food, water, and shelter to a variety of plant and animal species. The Ogeechee has been the source of much controversy as a large fish kill alerted the public to the possibility that the river and its inhabitants had been the victim of point-source pollution – a textile industry involved in the treatment of fabrics has been identified as releasing toxic chemicals into the river. The chemicals are thought to have weakened the fish’s immunity, allowing a bacterial infection to kill an estimated 33,000 fish.

Source:

Purpose of this Activity: To show energy flow through an aquatic ecosystem by constructing a model food web and to predict what might happen in one organism is removed from the food web by human activities (destruction, pollution, etc.)

Materials: handouts of printed plants and animals found in the Ogeechee River, handout list of these organisms, scissors, glue, colored pencils or markers

Methods: You and your partner will create a picture of the Ogeechee River showing examples of food chains and webs that could be found in this aquatic ecosystem. You should perform the following:

STEP 1:Complete the handout list of the organisms found in the Ogeechee River by naming probable food sources for each organism and filling-in the center column. You and your partner will need to use prior knowledge or internet research to identify these food sources for each organism. Then you and your partner will label each organism as a producer, herbivore, omnivore, carnivore, and/or decomposer based on their food source. In the column labeled “Symbol”, add the correct symbol for each organism’s food source (more than one symbol may fit some organisms):

  1. Producers = P
  2. Herbivores = H
  3. Omnivores = O
  4. Carnivores = C
  5. Decomposers = D

*Note: I left blank cells in case you and your partner would like to add appropriate organisms to

this list that you feel are important in this ecosystem!

STEP 2:Use scissors to cut the organisms from the handout of the plants and animals found in the Ogeechee River

STEP 3:Create a food web that begins with the sun and contains multiple producers, consumers, and at least one decomposer. Paste your food web on the provided blue paper. Using colored pencils or markers, draw arrows to show how energy is passed from one source to another. Remember arrows go from the organism that is eaten to the organism doing the eating!

*Note: I provided an extra copy of a few of the organisms to aid you in completing the food web.

STEP 4:Once your picture is done, put you your partner’s name & period on the bottom of the page.

Assessment: answer the following questions on a separate sheet of paper IN COMPLETE and DESCRIPTIVE SENTENCES!:

  1. What is the original source of energy for this and any food chain or web?
  2. What is the process performed by producers that convert this original energy into usable energy? Write the full equation.
  3. What is the chemical process that changes food (sugar) energy into usable energy? Write the full equation?
  4. In what ways do producers and consumers use energy, i.e., what life activities or processes do plants and animals perform that require energy?
  5. Give an example of a primary (first level) consumer from your food chain. Is this organism an herbivore, carnivore, or omnivore?
  6. Provide an example of a tertiary (3rd level) consumer from your food web. Is this organism an herbivore, carnivore, or omnivore?
  7. Provide an example of a decomposer from your food chain or web.
  8. Why are decomposers so important to ecosystems?
  9. Explain what may happen to the other organisms if toxins were to kill the fish in your food web. Which organisms would increase in population and why? Which organisms would decrease in population and why?
  10. What other activities, other than releasing toxic pollution, do humans do that might affect the food chains and webs in this aquatic ecosystem?

Assignments due:

  1. Organisms Found within the Ogeechee River handout completed by you and your partner in which you names food sources and identified their feeding level for the many organisms found in the Ogeechee River (with both partners’ name on it)
  2. Picture completed by you and your partner showing a food web that can be found in the Ogeechee River (with both partners’ name on it)
  3. Assessment Questions answered on a separate sheet of paper (with both partners’ name on it)

Staple all three pages together and turn them in for a LAB GRADE!

Name(s)______Period ______Date ______

Food Webs of the Ogeechee River: Organisms Found within the Ogeechee River

ORGANISM / FOOD SOURCE / SYMBOL
Algae
Alligator
Bacteria
Cypress tree
Bald Eagle
Banded water snake
Beaver
Black Willow tree
Blue Gill Bream (fish)
Bull frog
Catfish
Cottonmouth (Water Moccasin)
Dragonfly
Eel (freshwater fish)
Great Blue Heron (bird)
Largemouth Bass
Kingfish (bird)
Mushrooms (on bank of river)
Osprey (bird)
Phytoplankton
Raccoon
ORGANISM / FOOD SOURCE / SYMBOL
Red-eared slider turtle
Red Maple tree
River Birch tree
River Otter
Common snapping turtle
Water Lily
Water Oak
Wood Stork
Zooplankton
Another Organism You’d Like to Add:
Another Organism You’d Like to Add:
Another Organism You’d Like to Add:
Another Organism You’d Like to Add:

BACTERIABALD EAGLEBEAVER

BANDED WATER SNAKE RED-EARED SLIDER KINGFISHERBULLFROG

BLUE GILLWOOD STORK ALGAE

ALLIGATOREELRIVER BIRCH TREE BALD CYPRESS TREE

RIVER OTTERWATER OAK TREERACOON

ZOOPLANKTONPHYTOPLANKTONLARGEMOUTH BASS BLACK WILLOW TREE

COMMON SNAPPING TURTLEOSPREY CATFISH

WATERLILY

MUSHROOMCRAYFISHPHYTOPLANKTONZOOPLANKTON

DRAGONFLYGREAT BLUE HERONRED MAPLE TREECOTTONMOUTH

MUSHROOM

Ogeechee River Poster

Poster Completed by: ______

Name(s) ______Period______Date ______

Ogeechee River Fish KillExtra-Credit Assignment

Use the Internet and local newspapers to research the Ogeechee River fish kill that occurred summer 2011. Provide information about the following:

  1. What explanations have been proposed for this fish kill? Is this a natural or human-caused occurrence? Explain.
  1. Can any one specific organization (private industry, federal, state, or local government agency) be blamed for this environmental problem? Explain.
  1. What environmental laws or regulations apply to this event? After researching the fish kill, would you make any changes in our current environmental laws? If so, what would you change?
  1. Has this activity or the information you found online changed the way you may use the Ogeechee River in the future? If so, how?