Red Tide Activity 4: How Does Plankton Shape Affect Plankton Movement?
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Purpose:
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To determine how plankton maintain their position in the water column.
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Time Required:
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One class period (40-50 minutes)
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Safety issues:
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None
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Materials:
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Jars or trays
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Water
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Various pieces of paper
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Metal
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Cardboard
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Glue
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Cloth
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Timer or clock with a second hand
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Vegetable oil
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Procedure:
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Look at several pictures of plankton. Discuss how their shape and surface
area affect their ability to float.
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Choose one material at a time. Bend, twist, and/or glue the material
into different shapes. Test each material five times. First
wet it completely (to eliminate surface tension). Then measure the
time it takes to sink to the bottom.
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Repeat step 2 with the other materials. Design a basic data table
to keep track of your materials and times.
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Some plankton produces oil and store it in their bodies. Try folding
some material so it will hold about a teaspoon of oil. Determine
how this affects flotation.
Click here for Pictures of Plankton
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Assessment:
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Which material floated the longest? Which shapes?
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Do you think waves and currents affect plankton movement? How?
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Why do phytoplankton need to stay near the surface?
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Where do you think zooplankton are found in the water column?
(Hint: Zooplankton eat phytoplankton)
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Extensions:
If you live near a fresh water pond or body of salt water,
you can catch plankton and observe them under a microscope. Make
your own plankton net! It's easy. Obtain a leg of nylon panty
hose, a wire hanger, string, a rubber band, and a small jar. Place
the jar in the toe of the pantyhose. Keep it in place by tying it
or placing the rubber band around the lip of the jar.
Click here for Plankton net picture
Internet Links:
http://pipeline.com.au/users/huge/MRNElife.html
Background:
This activity requires a student to be familiar with basic plankton
concepts. Use during discussions of food webs or plankton.
Key Words
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plankton
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phytoplankton
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zooplankton
