Discover a Pond Food Web

Objective

Students will learn about the diversity of animal life in a pond and the interdependence among pond organisms.

Materials

• Boots
• Dip net with a fine mesh
• Collecting jars
• White-bottomed collecting pan
• Magnifying glass
• Portable folding table
• Copies of Reptile and Amphibian (Herp) Checklist
• Microscope (optional)
• Pond and Stream Safari by Karen Edelstein (optional)
• Field guides:
  
  Regional
  Harding, J. H. Amphibians and Reptiles of the Great Lakes Region. Ann Arbor, MI: University of Michigan Press, 1997.
  
  Klemens, M. W. Amphibians and Reptiles of Connecticut and Adjacent Regions. Bulletin 112. Hartford: State Geological and Natural History Survey of Connecticut, 1993.
  
  General
  Behier, J. L., and P. W. King. The Audubon Society Field Guide to North American Reptiles and Amphibians. New York: Alfred A. Knopf, 1979.
  
  Conant, R., and J. T. Collins. A Field Guide to Reptiles and Amphibians: Eastern and Central North America, 3rd. ed. Boston: Houghton Mifflin, 1991.

Procedure

1. View background information on food webs.
   
   
2. Have students fill the bottom of the collecting pan with water from the pond and place it in the shade to keep it cool. Dip the net into the pond and then carefully turn it inside out in the water in the collecting pan, releasing whatever has been caught. Take samples from various microhabitats, including the surface, the bottom, sediments, and within vegetation.
   
   
3. How many organisms can students pick out and identify? Even if they can't identify the species, can they guess the role the organisms might play in the pond community? (For more information about sampling, identification, and natural history of pond insects and other invertebrates, obtain a copy of Pond and Stream Safari or a field guide to pond life.)
   
   
4. Have students take the samples of water and examine them under the microscope. How many different organisms can they count? How many plants? Howmany animals? Try collecting some pond scum. What kind of creatures do youfind? Where do they fit in the food web?
   
   
5. Have students observe the rest of the animal life in and near the pond. Look for birds, fish, turtles, egg masses, and signs of animals, such as animal tracks, feces, underground burrows, and nests. Discuss what the different animals may be eating. From what they have seen, can the students surmise who are the predators and prey? Have them imagine being a specific reptile or amphibian living in the pond. What would they eat? How would they avoid being eaten?
   
   
6. Ask the students to draw a food web of the pond based on their observations.