Billion Oyster Project

Observe Oyster Spat-on-Shell


Oyster Tank Investigation



Class Periods




Subject Areas

Science, Math


Students closely observe live spat-on-shell and record their observations.


  • Make close observations.
  • Identify live versus dead oysters.

Materials and Resources


  • 10 oyster clumps with live spat-on-shell
  • Paper towels
  • Nail polish

Before you get started

Tips for Teachers

  • This lesson is designed to be completed in preparation for setting up a classroom oyster tank. The spat-on-shell oyster clumps that the students observe in this lesson are the same oysters that are put into the classroom tank.
  • Figure out when you will get your oyster clumps from Billion Oyster Project and how long it will be until your class is ready to set up the oyster tank.  Be sure to have a plan in place to keep your oysters alive during that time. See the Oyster Tank Guide for more info.

Instruction Plan


    1. In this activity, students get a close look at the spat-on-shell that will live in their classroom tank.

    2. Explain: These oyster clumps are the same ones that will live in the classroom tank once we set it up.

    3. Students get into small groups. Ideally, there should be 10 groups - one group for each oyster clump that will be placed in your classroom tank.
    4. Students start by observing the oyster clump and making a list of detailed observations.  Then they sketch both sides of the oyster clump.
      • Discuss: Similarities and differences groups noticed about their oyster clumps? 
      • Discuss: Observation of any organisms other than oysters? Invertebrates? Vertebrates? Can we identify any of them?  Students can refer to the these Species ID Resources.
      • Discuss: Did you have both live and dead oysters?  How could you tell?

    5. Describe: The methods to determine whether an oyster is dead.  Reminder: Small oysters (<2cm) are very fragile.
      • Gently try to pry the oyster shell open with your fingernail. A dead oyster will generally open very easily. A dead oyster can be filled with mud, so don't mistake that for being a live oyster.
      • Shell is visibly open.
      • Softness in the shell.
      • Bubbles discharged when the shell is lightly pressed.
      • Hollow sound when tapped.

    6. Students return to their oyster clump, identify live and dead oysters and record findings on the Spat-on-Shell Observations worksheet.

    7. Students need to get to know their oyster clump very well.  We hope students also begin to form an interest in and attachment to their oysters.  After all, the students should be responsible for maintaining the tank and caring for the oysters throughout the school year. 
      • Discuss: How will students be able to identify their oyster clump once it’s mixed in with the other clumps in the tank?  Are there any oyster clumps that have distinguishing features?
      • Each group gives their oyster clump a name.
      • Hand out the nail polish.
      • Students dry off the oyster clump and using the nail polish, paint a number (1 through 10) on it, so each clump has a unique number.  

    8. Consider hanging up a poster that includes the number of each oyster clump and its corresponding name.


    NYC Science Scope & Sequence - Units

    • Grade 6, Unit 4

      • Interdependence
    • Grade 7, Unit 4

      • Dynamic Equilibrium: Other Organisms