Billion Oyster Project

Is Our Tank Ready for Animals?


Nitrogen Cycle Investigation



Class Periods




Subject Areas



Students graph the ammonia/nitrite/nitrate data they have been collecting and compare their graphs to a professional aquarium graph.  After investigating these graphs the class decides whether their tank is ready for animals.


  • Create a graph based on their data.

  • Compare their graph to one from another source.

  • Build consensus about whether the classroom tank is ready for animals.

Materials and Resources

Teacher Resources


  • Graphing supplies (either analog or digital)

Before you get started


  • Compile the ammonia/nitrite/nitrate data from the students’ monitoring of the classroom tank over the past weeks.  Prepare the data so there’s a copy for each student.

  • Be prepared either to take the next step with your tank set-up at the end of this lesson!

    • If the students agree that the tank is ready for animals be prepared to add oysters, and possibly other organisms.  

    • If there are legitimate concerns among students about adding organisms, ideally be prepared to start a second tank with a fishless cycle so you can create a comparison tank.

Instruction Plan


  1. Each student gets a copy of the ammonia/nitrite/nitrate data from the classroom tank.

  2. Students graph each parameter over time on a single graph.  

  3. Students get into small groups, compare their graphs and make observations about their graphs.


  1. Each student gets an Observation / Inference / Questions handout.

  2. Students work in their small groups to write down things they notice about the graphs.  They note patterns, connections, and questions that each observation raises for them.

  3. Students get Is Our Tank Ready for Animals? (which includes the graph below) and complete it with their small groups.

  4. Consider re-distributing Diagrams that Describe Nitrogen Changes in Tanks and or Nitrogen and Estuaries Topic Library (from previous lessons in this Investigation) in order for the students to cite additional evidence to support their claim.




  1. Discuss: Is our tank ready for animals?

  2. Push for evidence, and a discussion in which students talk to each other.  

  3. Add your animals!  Consider making this into a ceremony, as the students have done a lot of work in the past weeks to get to this point.

  4. If there is legitimate controversy and the class cannot build consensus, consider starting a second tank to accommodate multiple conclusions.


  1. Discuss: How does the nitrogen cycle in our tank compare to the nitrogen cycle in the estuary?

  2. Will our oysters do better in our tank or in our Oyster Restoration Station (ORS)?


NGSS - Cross-Cutting Concepts

  • Energy and Matter

    • Matter is conserved because atoms are conserved in physical and chemical processes.

NGSS - Disciplinary Core Ideas

  • ESS2.A: Earth’s Materials and Systems

    • All Earth processes are the result of energy flowing and matter cycling within and among the planet’s systems. This energy is derived from the sun and Earth’s hot interior. The energy that flows and matter that cycles produce chemical and physical changes in Earth’s materials and living organisms.
  • LS2.B: Cycle of Matter and Energy Transfer in Ecosystems

    • Food webs are models that demonstrate how matter and energy is transferred between producers, consumers, and decomposers as the three groups interact within an ecosystem. Transfers of matter into and out of the physical environment occur at every level. Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem.

NYC Science Scope & Sequence - Units

  • Grade 6, Unit 4

    • Interdependence

NYS Science Standards - Major Understandings

    • Matter is transferred from one organism to another and between organisms and their physical environment. Water, nitrogen, carbon dioxide, and oxygen are examples of substances cycled between the living and nonliving environment.