Bringing in the Pond with iMovie

Unit details
Subject: Biology
Learning Levels: Primary
Author:  Randy Yerrick

Invitation
How many animals can you name in the pond?  In your list did you think of any animals that cannot be seen
with just your eyes?  Every drop of water can actually contain dozens of animals busily feeding on algae or
hunting each other.
 

Situations
Throughout the course of a week students will be given the opportunity to examine pond water samples and
contribute a classroom bulletin board collection or journal.  Students can print their pictures, write stories or
descriptions of animal behaviors, or save their findings in an ongoing classroom pond portfolio or web page.

Tasks
Much of the important life in ponds is actually invisible on site if you cannot carry a microscope into the field.
Once the pond water is collected and brought back to the classroom, this activity can be treated as a scavenger
hunt and exploration of the hidden aquatic world.  Looking more carefully at smaller organisms students can
observe what small fish, larvae, tadpoles, and other small visible animals feed upon.  It can also help to fill in
gaps in the students' understanding of pond food webs.  By investigating microscopic habitats students can be
encouraged to generalize certain behaviors from visible animals (e.g.: eating, transportation, predator/prey
relationships) to all life forms big and small.

Students are given a list of things to find and a set of well labeled samples.  They are then invited to explore and
capture different evidence of microscopic life.

Divide students into pairs of investigators and schedule times for exploration.  Provide students with specific
categories to fill in and places to post their findings.  Some of the categories that can be used include:

A plant that contains chlorophyll.
An animal that harvests or eats algae or other plants. (Protozoan)
An animal that eats other animals.  (Foraminifers)
An animal that is found that the top layer but not at the bottom.
An animal found in both the bottom and the top layer.
A worm like animal.
Animals which flow for locomotion.  (Amoebas)
An animal that propels itself with a whip (Euglena).
An animal with cilia which look like hair. (Ciliata)
An animal with observable eyes.
An animal with  a visible intestine.
An animal with color--not just transparent.

As an extension, take a scoop of the pond mud and allow it to settle under a later of water.  After 48 hours,
observe carefully for snails, worms, and insect larvae.  Microscopic observations should also be made.  Once all
careful records are taken, allow the mud to dry as the water above it evaporates.  Discuss with students what they
think will happen to the life they observed.  After students have had the opportunity to write about and discuss
their predictions the teacher should re-introduce distilled water.  It is important that chlorinated water not be used
because it may kill some animals.  Pond water  should also be avoided since it likely contains its own animals
introduced into the dried up pond.    Students should make another round of observations documenting which
animals can be found alive and which are not observed.  Students should be encouraged to discuss and imagine
how aquatic animals can survive such harsh conditions (encysting) and why these characteristics would be vital
to their survival.
 

Interactions
This is a cooperative activity that allows all students to contributed to a common project.  Students will be
observing, describing, drawing, and explaining their findings with the whole class.  While the teacher may need
to assist in the basic operation of the microscope and slide preparation, the students can generally explore
independently and record their observations.   A common question board posted next to the microscope can also
be a venue to generate other student interactions and investigations.
 
 

Assessement
Assessment is highly dependent upon age level and experience.  For K-2 , children conducting a scavenger hunt
should be assessed on their ability to recognize differences in shapes and habits of aquatic animals, noting their
observations through pictures and oral presentations.  Upper elementary students should be able to recognize
plant from animals and look for common characteristics among animals (e.g.: feeding, locomotion).  Upper
elementary students should also begin to document their observations in a writing journal with illustrations and
be encouraged to write creative stories for assessment.  Middle grade students should begin to learn basic
categorization of the animal kingdom while high school students should be able to identify animals by name and
apply their knowledge of food webs, energy, and other biology concepts to write a full scientific report on the
life in the pond.  High school students should also be able to design their own studies of pond water quality
based upon the kind and number of animals found.
 

Tools
iMovie, digital video microscope, pond water samples, age appropriate references.