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A Perfect Home

Activity Summary

Students learn about oyster reef building and the inhabitants of oyster 

reefs. They build model reefs using everyday materials and refine their 

designs based on additional information.

Learning Objectives

Student will be able to:

• Explain the role of Eastern oysters in the Chesapeake Bay

• Explain the importance of an Eastern oyster reef to oysters

• Use a model and a diagram to explain an idea

Essential Question

How can we clean the water of the Chesapeake Bay to improve the 

habitat for plants and animals?

Background Information

Oysters, a type of mollusk, are animals that have a soft body 

surrounded by two calcareous shells that live in coastal waters. Some, 

but not all, oyster species also form dense clusters that are typically 

referred to as oyster reefs. 

K-12 Oysters in the Chesapeake Bay

Grade Level: 

Grade 2

Teaching Time: 

3-5 30-45 minute sessions

Materials:

• 1-2 live Eastern 

oysters, Crassostrea 

virginica,Eastern 

oyster shells

• Glass aquarium or 

other container

• Images or video of 

oysters with and 

without reefs

• Video of oysters

filtering water (see 

Day 1 Exploration)

• Science journal

• Drawing paper

• Chart paper

• Craft construction 

supplies described in 

Day 2 Exploration

• Copy of the Student 

Resource for each 

student
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Historically, oysters in North America have served many purposes for the inhabitants of coastal 

areas. Aboriginal North American Indians found oysters to be an abundant and reliable source of 

food, and they also used the shells as tools, weapons, ornaments and even currency. Today, oyster 

harvest and cultivation provide significant economic value to regional coastal communities. 

In addition, oyster reefs provide habitat for other species, including some commercially important 

species. They filter the water and increase water clarity by extracting organic and inorganic 

particles from the water column. In turn, this increase in water clarity promotes the growth of 

submerged aquatic vegetation, which also provides habitat for other organisms.

However, the loss of oyster reefs in the United States during the past 200 years has been 

significant. Due to over-harvesting, increased sedimentation, pollution, invasive species and 

disease, the amount of oyster harvest has decreased dramatically—reducing income and jobs for 

workers in the oyster industry. But just as important, the loss has removed habitat for other 

animals and plants and decreased water quality in estuaries and coastal waters.

Key Words

Bivalve - An aquatic mollusk that has a compressed body enclosed within a hinged shell

Disease - A condition that impairs the proper function of the body or of one of its parts

Ecosystem - All the living organisms that occur together in a particular area

Filter - To separate or remove matter

Habitat - Place where an organism or a community of organisms lives; includes all living and 

nonliving factors or conditions of the surrounding environment

Harvest – Process of gathering as in a crop

Hatchery – Place where oyster larvae and young oysters are grown

Larvae – Early form of an animal that is unlike its parent; Must change to look like/act like 

parent

Mollusk - Invertebrate that has a soft unsegmented body and lives in aquatic habitats and often 

has a shell. 

Oyster - Bivalve mollusk with rough irregular shell sometimes eaten as a delicacy and may be 

farmed for food or pearls

Oystermen – Women and men who harvest oysters to sell to restaurants or to eat themselves

Phytoplankton – Free swimming algae
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Pollution – Contamination of air, water or soil with harmful substances

Reef – Strip of oysters rising close to the surface of the water

Restore – Bring back into existence

Spat – Name for oyster larvae after the attach to a surface

Substrate – Base on which an organism lives

Water current - Part of a fluid body (as air or water) moving continuously in a certain direction

Activity Procedure

Day 1

Engagement 

Give each student, or team of students, oyster shells. If you do not have actual shells, show

images of individual Eastern oysters. Ask them to describe what they see and feel. Have them 

guess what they are holding or seeing in the images. Ask what they know about oysters, and 

chart their answers for use on Day 2.

Exploration

1. Show the students a video of an oyster filtering dirty water. Videos are available on You 

Tube and Teacher Tube by searching “oyster filtering.” Be sure any images or videos you 

show at this point do not show oyster reefs. Discuss what they think is happening in the 

video.

2. Place two live oysters in an aquarium or another container full of dirty water the 

students can observe. Have students record their predictions about what will happen to 

the water in the container overnight in their journals.

Day 2

Engagement

Show the aquarium or container with the oysters to the students. Ask them what happened 

and why they think a change occurred? They can record their answers in their journals and 

share them with the class.

Exploration

1. Pose the following problem to the students, “When oysters filter water from the 

Chesapeake Bay, they remove sediment and chemicals, which helps keep the Bay 

ecosystem healthy. There are not enough oysters left in the Bay to clean it as there 

once were, and animals are suffering. What can we do?”
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2. Discuss how the students would solve the problem. (Create/Grow more oyster 

beds.)

3. Explain to students that scientists have tried a variety of different ways to recreate 

oyster beds and reefs, and now the students will undertake the same process by 

designing an oyster reef.

4. Discuss the life-cycle of the oyster, from free-floating spawn, to swimming and 

crawling larvae, to attached spat, to mature oyster. What factors in their 

environment will help them survive?

5. Provide the students with a large piece of paper. This will be the substrate on which 

the oyster reef will sit. Have students choose a substrate based on their 

observations of the oysters and label it on their paper (sand, mud, deep water, 

rocks, shells, etc.). 

6. Give students a variety of material such as egg carton cups, construction paper, pom 

poms, pipe cleaners, fun foam, packing peanuts, etc.

7. Have students build their reefs.

Day 3

Engagement

Ask students to share their reefs. Have them explain the parts of their design and why they 

chose their reef design.

Exploration

1. Ask students to read the Student Information page about oysters. Discuss the topic of 

the text and draw their attention to the paragraphs describing oyster reefs. Have them

talk about the answers to the following questions with a partner based on the reading: 

How are oyster reefs made? What do you think they look like based on what you read?

2. Share pictures and/or videos of oyster reefs with the students. Discuss student 

observations about the reefs.

3. Working with a partner, have students compare their reefs with the pictures/videos and 

discuss how they could change the design of their reefs to look and function more like 

real oyster reefs.

Explanation

1. Ask students to explain their original design (draw a picture) and the modifications they 

want to make based on what they learned.

2. Give students time to make changes to their reefs or build a new one if possible.

3. Explain that the process of designing an object and making modifications based on new 

information is the same process scientists and engineers undertake. This is how they 

found out that old oyster shells are the best substrate on which to build new oyster 

reefs.

4. In their journals, ask students to reflect on the activities by explaining why oyster reefs 

are good for oysters, and for fun, the three favorite things they learned about oysters. 

They should explain why they chose each one.
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Extension

1. Discuss the homes of other animals, especially those that build or grow them like 

oysters (beavers, rabbits, groundhogs, bees, birds etc.). Show pictures of these homes 

and talk about the special features of each home that make them a perfect fit for the 

animal.

2. Ask students to create and draw an imaginary animal. You can draw one for the class to 

use if time is limited. Label each part. The animals should be based on real 

characteristics of animals such a long legs, fur, big ears, etc. No animals with computer 

or robot parts.

3. Now ask the students to design the perfect shelter for the animal by drawing and 

labeling a picture of their design.

4. Have the students share their designs explaining why they gave their structure certain 

features and how those features “fit” the animal.

5. In their journals, have the students compare and contrast an oyster reef and the home 

of the imaginary animal. Make sure they introduce the topic, use facts and definitions to 

explain the similarities and differences, and provide a concluding statement.

Evaluation

Formative: 

1. Class discussions and participation

2. Journal entries

Summative: 

1. Model designs and modifications, if applicable

2. Journal reflection on oyster reef design

3. Diagrams of imaginary animals and homes

4. Journal entry comparing and contrasting homes
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Education Standards

Three Dimensional Learning

Disciplinary Core 

Idea(s)

2-LS4.D: Biodiversity and Humans

There are many different kinds of living 

things in any area, and they exist in 

different places on land and in water.

(2-LS4-1)

How Standard is Addressed

Students learn about the 

locations of oyster reefs and 

how vital they are to the Bay 

ecosystem.

2-ETS1.B: Developing Possible 

Solutions 

Designs can be conveyed through 

sketches, drawings, or physical models. 

These representations are useful in 

communicating ideas for a problem’s 

solution to other people. (K-2-ESTI -2)

2-ETS1.C

Optimizing the Design Solution -

Because there is always more than one 

possible solution to a problem, it is 

useful to compare and test designs.

Students construct oyster 

reef models to demonstrate 

how scientists solve a reef 

design problem and modify 

their designs to reflect new 

information. They also draw 

and diagrams of homes for 

imaginary creatures.

Science/Engineering 

Practice

Planning and Carrying Out 

Investigations

Make observations (firsthand or from 

media) to collect data that can be used 

to make comparisons.(2-LS4-1)

Developing and Using Models

Modeling in K–2 builds on prior 

experiences and progresses to include 

using and developing models (i.e., 

diagram, drawing, physical replica, 

diorama, dramatization, or storyboard) 

that represent concrete events or 

design solutions.

Develop a simple model based on 

evidence to represent a proposed 

object or tool. (K-2-ETS1-2)

Students construct oyster 

reef models to demonstrate 

how scientists solve a reef 

design problem and modify 

their designs to reflect new 

information they observe 

from a reading, photographs 

and videos. They also draw 

and diagrams of homes for 

imaginary creatures.

Cross – Cutting 

Concepts

Structure and Function

The shape and stability of structures of 

natural and designed objects are related 

to the function(s).

Students learn how oyster 

reefs are formed, their 

structure, and the best 

substrate in which to place 

reefs.
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Common Core Standards

Ties to Common 

Core

RL2-2

Identify the main topic of a multiparagraph text as well as the focus of 

specific paragraphs within the text

RL2-4

Determine the meaning of words and 

phrases in a text relevant to a grade 2 

topic or subject area.

W2-2

Write informative/explanatory texts in 

which they introduce a topic, use facts 

and definitions to develop points, and 

provide a concluding statement or 

section.

RL2-2

Students read an informative 

text about oysters, discuss 

the topic of the text and focus 

on one section to gather 

information to inform their 

reef designs.

RL2-4

Students learn new 

vocabulary during class 

discussions and reading. They 

apply this new knowledge to 

discussions and in the 

summative assessments.

W2-2

Students write an informative 

piece comparing and 

contrasting oyster reefs 

(homes) with a home for an 

imaginary creature. They use 

points about each structure 

to develop the explanation.

Maryland Environmental Literacy Standards

Ties to MD 

Environmental 

Literacy Standards

Standard 2 Interactions of Earth’s 

Systems

Topic B: Systems Thinking

Indicator 2: Use models and computer 

simulations to extend his/her 

understanding of scientific concepts.

Students develop and analyze 

models of oyster reefs.
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Additional Resources

Web Resources

Protecting Our Water Resources: Student Activities for the Classroom Water and educational 

activities for Kindergarten through Ninth Grade 

http://www.stormwater.ucf.edu/toolkit/vol3/Contents/pdfs/Student%20Activities/student_act

ivities.pdf

Olly the Oyster: Visit this website for coloring pages, puzzles, word searches, crafts, and more. 

http://www.ollytheoyster.com

Sammy’s Corner: An Oyster Recycling Program: The site contains teacher resources including a 

poster, curriculum guides, and additional oyster activities. 

http://oysterrecycling.org/sammys-corner/

How to Make an Oyster Using Egg Cartons: Online instructions showing children and adults how 

to make an oyster model from an egg carton. 

http://familycrafts.about.com/od/eggcartoncrafts/ss/eggcartoyster.htm

Note: You can skip a step by cutting adjacent cups and folding them along the divider 

separating the cups for the oyster’s hinge.

YouTube Videos:

• Oyster Filtration: A one-minute time-lapsed video of oyster filtration in action. 

https://www.youtube.com/watch?v=saAy7GfLq4w

• OYSTERFILTER: A one minute and 20 second time-lapsed video of six oysters filtering a 

gallon of water. https://www.youtube.com/watch?v=LOp3V_QpAyA

TeacherTube Videos:

• Oyster Filtering: Excerpt from The Chesapeake Bay Foundation's documentary

"Common Ground.” (42 seconds)

• http://www.teachertube.com/viewVideo.php?video_id=211324

• Oyster Rap: An oyster restoration scientist raps about Eastern oysters in the Chesapeake 

Bay

• http://www.teachertube.com/viewVideo.php?video_id=93158

Book Resources

Allen, Elaine Ann. Olly the Oyster Cleans the Bay. Tidewater Publishers, May 1, 2008. ISBN-10: 

0870336037. 

Tate, Suzanne. Pearlie Oyster: A Tale of an Amazing Oyster. Nags Head Art, Inc., June 1, 1989. 

ISBN 10: 0961634472. 
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Student Resource

The Eastern Oyster in the Chesapeake Bay

Two halves of a single Eastern Oyster.

What are Eastern oysters, Crassostrea virginica?

Eastern oysters are bivalve mollusks. That means they have two shells. 

You will see one shell on the left side and one shell on the right side 

when you open an Eastern oyster. 

Where do Eastern oysters live?

Eastern oysters live on the East Coast of North America from Canada to 

Venezuela.

Very young oysters float in water currents looking for a place to stick to 

and grow into adults. As they float, they grow a foot. They use the foot 

to find a hard surface to attach to. Then they make a cement-like glue 

to stick the foot to the hard surface. They cannot attach to mud and 

sand or to a place with too much sunlight. They need to be in flowing 

water where their food (phytoplankton) is. Other oyster shells are the 

best place for oyster larvae to attach. Once attached, the larvae are 

called spat. Over time, the spat grow and make shells, and other oyster 

larvae attaches to them. As more and more oysters attach to older 

oysters, oyster reefs grow. 
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Oyster spat attached to oyster shell (left), restored oyster beds. Photo: NOAA

What do Eastern oysters look like?

Adult Eastern oysters have a grey and white bumpy shell. They are 

shaped like giant kidney beans with one skinny end. They can grow to 

eight inches long. There were once oysters as big as dinner plates!

Those oysters had grown for many years because Native Americans 

could only harvest small numbers of oysters.

Why are Eastern oysters important to the Chesapeake Bay?

For thousands of years, people have eaten Eastern oysters, and Native 

Americans used oyster shells for jewelry and money in the past. 

Starting about 400 years ago, people also made money by harvesting 

and selling oysters.

Eastern oysters filter the water in the Bay. Oysters suck in water and 

filter out phytoplankton for food. They also filter sediment and 

pollution out of the water. Then they spit clean and clear water back 

into the Chesapeake Bay. Without oysters, the water in the Bay would 

become cloudy and polluted; not a good place for other animals to live.

Oyster reefs also provide habitat to other animals such as small crabs 

and fish. The young animals live in the oyster reefs for protection from 

predators and for food.
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What happened to the Eastern oysters?

For hundreds of years, Eastern oysters were known as the best tasting 

oysters in the United States. Oystermen harvested oysters faster than 

the oysters could reproduce. Oysters live close together in reefs, and 

their young like to stick to other oyster shells to grow. There were not 

enough oysters to reproduce or provide shells for oyster larvae to 

attach to, so fewer oyster reefs were made. People also used oyster 

habitat as places for building docks and houses.

Also, in the 1940s and 1950s, scientists found two diseases in Eastern 

oysters called MSX and Dermo. Both of these kill oysters and make it 

harder for more reefs to grow in the Chesapeake Bay.

What are people doing to help the 

Eastern oyster?

People are doing many things to help the 

Eastern oyster. Scientists are learning 

more and more about oysters and their 

habitat, and water currents in the 

Chesapeake Bay. They use this information to find the right places to

place piles of empty oyster shells to give oyster larvae sticking places. 

The new reefs are often built on old oyster shells from restaurants.

People are also growing oysters from boat docks in bags that look like 

mesh socks and give the oysters to oyster restoration groups to put 

onto reefs when the young oysters are large enough. Businesses are 

growing oysters on floating rafts. They sell the oysters for food and use 

the shells to help new oysters grow.

What can you do to help the Eastern oyster?

Learning about the Eastern oyster is the first step toward helping more 

oysters grow in the Chesapeake Bay. You can share the story of the 

Eastern oyster and its importance to the Chesapeake Bay and to 
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Maryland with others. You can also collect oyster shells from 

restaurants and take them to groups around the Chesapeake Bay who 

are working to restore oyster beds. If you live on the Bay, you can grow 

oysters from your dock in oyster socks and then take the sock to a 

group that will plant them on an oyster bed. And if you are boating in 

the Chesapeake, watch for oyster beds. Putting down your anchor on a 

bed can hurt the living oysters and destroy the bed. Anything you do to 

bring oysters back to the Chesapeake Bay benefits all Marylanders and 

Virginians.

Tiny oysters at a hatchery.