Billion Oyster Project

Small Tanks for Small Arthropods


NY Harbor Populations Investigation



Class Periods




Subject Areas



In small groups, students become stewards of a number of the small animals their class gathered from the Oyster Restoration Station (ORS) -- probably some combination of arthropods including amphipods, isopods, crabs, and/or shrimp.  Students develop a system for identifying and tracking their animal community, make decisions about how best to keep the animals, and develop their questions about these ORS animals.


  • Develop a system for identifying and tracking small arthropods from the ORS.

  • Make and justify decisions about how best to keep those animals

  • Collect data to check how well they have been keeping their animals.

  • Develop questions about the animals.

Materials and Resources


  • Poster paper for each group to record baseline data

  • 20 (or more) Petri dishes

  • White paper to lay out under the Petri dishes, so it’s easier to observe the animals on a white background

  • Tweezers (one set for each table) -- for transferring animals

  • and/or Wide-tipped disposable pipets (which are quite reusable)-- for transferring animals more gently, along with some water -- one or two per table

  • Sieves, screens, or pieces of loosely-woven fabric that can be used to separate animals from water (one for each table)

  • Hand lenses (two or more for each table)

  • 10 (or more) one-gallon tanks (e.g. Penn-Plax New World Habitat Tank, Small, 1 gal)

  • At least 30 small arthropods collected from ORS mobile trap (the more the better!)

Refer to the BOP Oyster Tank Guide on the BOP Digital Platform for details on where to purchase and how to use the materials for your small tanks.

  • Cold tap water -- enough to fill all the 1-gallon tanks

    • Tap Water Conditioner (de-chlorination of tank water)

    • Instant Ocean Aquarium Salt (15 lbs bag)

  • OR harbor water -- enough to fill all the 1-gallon tanks

  • 10 (or more) aerators with airstones and tubing (alternatively, you can use a manifold with extra tubing to divide the air from one aerator into several tanks)

  • Shellfish Diet 1800 phytoplankton concentrate (1 quart) OR algae discs (optional for occasionally feeding the associated organisms)

  • Optional: frozen brine shrimp for feeding crabs, if students don’t want the crabs eating the harbor organisms

    • Purchase at your local aquarium store or Petco

  • Optional: Stress Zyme (for adding more bacteria to your tank)

  • Optional: Aquarium gravel (for DIY filters)

  • Optional: Plastic bottles with wide mouth (for DIY filters that can fit inside the little 1-gallon tanks)

  • Optional: Recycled oyster shells for substrate

Before you get started

Tips for Teachers

  • Because students often ask fantastic questions without realizing it or writing them down, try to move around the room and write down the wonderings you overhear.  

  • Each time you move or handle your organisms, you stress them.  In general, sieving or screening them is less stressful than using tweezers.

  • You might first ask your students to practice using tweezers gently on other objects, such as soft-cooked rice or cut up cooked noodles.  If they break the rice grains or noodle pieces, they’re squeezing too hard.

  • The hope is to allow students to explore and interact with these animals, and to do so gently, with awareness of how their actions affect the animals.

  • During the data collection period, in the “Evaluate” section, you may want to split class time:  each day students can have a certain amount of time to collect their data.  If you like, you can use the remaining class time from each of those periods for students to present their experiments and data to date.  Groups can present what they have so far, and that way you don’t need to wait for everyone to collect all their data before getting started on presentations.

  • In order to do the Extension for this lesson, you will probably need a fresh supply of animals.  That means visiting the ORS again before that part of the lesson, either with or without your students.


  • You need animals from your Oyster Restoration Station (ORS), and it’s best if your students have collected those animals.  Ideally, schedule this lesson right after a visit to the ORS.  
  • For the “Elaborate” section, you probably need to make your own handout, based on which resources are available to your students in your classroom. 
  • So that your students have some background knowledge about these animals and the local estuarine ecosystem, we recommend that you teach the lessons Food Web and Habitat Web prior to this lesson.

Instruction Plan


  1. Note: the next activity is a rich source of student questions about small arthropods.  Be sure to record your students’ questions and add them to your running list.  You’ll need that list for the students to propose large-scale studies in the upcoming lesson, Propose a NY Harbor population study.

  2. Explain:  

    • “You each have a small tank, which could be enough space to support a number of small animals, if you make good decisions and take good care of them.  Your job is to decide what conditions will be best for your animals in that tank.

    • “If you want to separate your animals, or use a different group of animals together in one tank, let me know.  At a certain point, I will set up a discussion for those groups who want to swap animals and set up tanks with different sets of animals.

    • “Every tank must have aeration, but there are some different ways to manipulate the aeration.”

  3. Groups make decisions such as those below.  You probably need to make your own handout that lists the decisions should make, based on the resources available in your classroom.

    • Do we put all the animals we have in the same tank, or should we separate them?  If we want to separate them, we should tell our teacher within the first 15 minutes of this process.

    • Who eats what?  Shall we feed our animals with some added food, like algae paste, frozen brine shrimp, and/or algae disks?

    • Shall we let the animals eat each other?

    • Shall we continue collecting harbor water, and strain it through a sieve, so we get more phytoplankton, but we don’t get more amphipods and isopods?

    • Or shall we continue collecting animals from the harbor and adding them on a regular basis?  (Note:  you should probably offer this option only if you are willing to go collecting on a regular basis!)

    • Should our tank be covered or open to the light?  How much light, and what kind/source of light?

    • Should we put a lid on top of our tank or leave it open on top?  Should we seal the lid with some kind of tape?

    • We need aeration, but how and how much?  (You can split up the air from one pump using a manifold.  Suppose the manifold splits one line into four: then you can decide how many of those four lines to put in one tank).  Should we use air stones?

    • Should we make a DIY filter?

    • Should we have substrate in the bottom, or just water in the tank?

    • Etc.  The possibilities are endless!

  4. Students set up their tanks and add their animals.  (You will probably have to do some nimble negotiating to figure out which groups need which animals, and to distribute the animals to the groups.)

  5. Groups use the method they have devised for sorting and counting their animals, and post this baseline data.


  1. Note: the next activity is a rich source of student questions about small arthropods.  Be sure to record your students’ questions and add them to your running list.  You’ll need that list for the students to propose large-scale studies in the upcoming lesson, Propose a NY Harbor population study.

  2. Students write down what conditions they have selected for their tanks, and why.

  3. Students write down when and how they need to collect data, for the purpose of showing how well their animals are doing under their chosen conditions:

    • They have to track their animals, sticking with the system they devised in the “Explore” portion of the lesson.

    • They might also want to track water parameters.  For economy’s sake, you could limit this to parameters that can be tracked with non-consumable materials, e.g. temperature, pH if you have a pH meter, water level, water color, etc.

    • Note: there’s a decent chance that many of the animals will die within two weeks.  Also, each time people handle the animals, the animals are stressed.  So we recommend tracking the animals over a period of 5-10 days, and collecting data only 2 more times after the initial baseline count.

Over the next few class days, as data collection continues:

  1. Groups present their systems of sorting and counting their animals, the conditions they chose for their tanks, and their results.

  2. Students respond to each group’s presentation with follow-up questions and suggestions.


  1. Note: the next activity is a rich source of student questions about small arthropods.  Be sure to record your students’ questions and add them to your running list.  You’ll need that list for the students to propose large-scale studies in the upcoming lesson, Propose a NY Harbor population study.

  2. After getting, posting, analyzing, and discussing everyone’s data, groups respond to the more specific prompt:  “Define best.  You tried to set up your tanks in the way that would be best for your animals.  What did you mean by best?  What are some other ways of deciding what is best?”  

  3. Groups set up their tanks afresh, in the way that is ‘best’ according to their now-precise definition.  

    1. Note: you will likely need a fresh supply of animals for this step!


NGSS - Cross-Cutting Concepts

  • Cause and Effect

    • Cause and effect relationships may be used to predict phenomena in natural or designed systems.
    • Phenomena may have more than one cause, and some cause and effect relationships in systems can only be described using probability.
    • Cause and effect relationships may be used to predict phenomena in natural systems.
    • Relationships can be classified as causal or correlational, and correlation does not necessarily imply causation.
  • Energy and Matter

    • The transfer of energy can be tracked as energy flows through a designed or natural system
    • The transfer of energy can be tracked as energy flows through a natural system.
  • Influence of Engineering, Technology, and Science on Society and the Natural World

    • All human activity draws on natural resources and has both short and long-term consequences, positive as well as negative, for the health of people and the natural environment.
  • Patterns

    • Graphs and charts can be used to identify patterns in data.
    • Graphs, charts, and images can be used to identify patterns in data.
  • Stability and Change

    • Stability might be disturbed either by sudden events or gradual changes that accumulate over time.
  • Systems and System Models

    • Models can be used to represent systems and their interactions.
    • Models can be used to represent systems and their interactions—such as inputs, processes and outputs—and energy and matter flows within systems.

NGSS - Disciplinary Core Ideas

  • LS1.A: Structure and Function

    • Within cells, special structures are responsible for particular functions, and the cell membrane forms the boundary that controls what enters and leaves the cell.
  • LS2.A: Interdependent Relationships in Ecosystems

    • Growth of organisms and population increases are limited by access to resources.
    • Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors.
  • 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.
  • LS2.C: Ecosystem Dynamics, Functioning, and Resilience

    • Ecosystems are dynamic in nature; their characteristics can vary over time. Disruptions to any physical or biological component of an ecosystem can lead to shifts in all its populations.

NGSS - Science and Engineering Practices

  • Analyzing and Interpreting Data

    • Analyze and interpret data to provide evidence for phenomena.
  • Constructing Explanations and Designing Solutions

    • Construct an explanation that includes qualitative or quantitative relationships between variables that predict phenomena.
  • Engaging in Argument from Evidence

    • Construct and present oral and written arguments supported by empirical evidence and scientific reasoning to support or refute an explanation or a model for a phenomenon or a solution to a problem.

NYC Science Scope & Sequence - Units

  • Grade 6, Unit 4

    • Interdependence