Crab Crisis

WebQuest
Crab Crisis

Essential Understanding
Groups of organisms interact with each other and their environment.
Environmental conditions contribute to changes of populations in an ecosystem.

Click on Crabby to scurry to the section you need.

Introduction	Task	Step A
Step B	Step C	Step D
Resources	Evaluation	Conclusion

Introduction:

You were looking forward to the big family picnic because you were more than ready for steamed crabs!!! YUMMY!!

But wait! Your dad just said, "Sorry, no crabs. Too much money. A bushel of crabs costs $100."

What happened? No crabs? The family picnic is not the same without crabs!

So your father suggested you try crabbing from your grandfather's pier. Hey, why not? So you had set up some crab traps. But after you checked each one for a week, you were only able to get one dozen small ones. And they weren't big enough to keep!

Crabs weren't that difficult to catch last year. What happened?

You were so upset about this that you asked your teacher to help you investigate this crisis.

Task

You found out from your classmates that they are also having some difficulty in catching crabs. Their parents weren't too happy about the high prices either.

Your teacher had helped you contact some places that sell crabs to find out why they are so expensive. Then you found out that the crabs in the market are not from Maryland, but instead from other states.

Not from Maryland! Why not? Crabs are supposed to be part of Maryland's culture.

Later on, you heard on the news, that crabs in Maryland are scarce. They are not as plentiful as they use to be.

Why?

Since this is affecting your whole class, including your teacher, the class has decided to conduct an investigation into this problem.

You and your teammates will be collecting information on the crab crisis. You will be writing a booklet to inform other fifth graders about the crab and its life in the Chesapeake Bay.

Step A
Before you can begin to understand what might have happened to the crab population, you need to understand what makes a crab, a crab. What does it look like? How is it different from us? How does it move around and protect itself ? What does it eat?
   Notice where the eyes are located. The legs are bendable. The two front claws can easily reach the mouth. Why?
Photographs taken from Blue Crab Archives with permission

This is a sook, a female crab. What do you call a male crab?
You and your teammates need to gather information on the appearances and behavior of crabs.
1. RECORD: You will need to use a data chart to record information. Click on the Crabby to bring up a copy of this data chart. Then using pencil, ruler, and paper, neatly construct your own copy of this chart.

2. SHARE WORKLOAD: Look at the table below. You and your teammates need to decide which source of information each of you will use to look for details to record onto your data chart. Divide the work up and share the information that you find. Be sure to closely examine any photographs or pictures for information as well.
3. SEARCH: On the table below, each block has a picture of Crabby. Click on Crabby to search for information that will describe the blue crab's appearance and behavior.
4. RECORD: As you locate each source that you have chosen, record the information on your data chart under the appropriate headings.

Identifying the blue crab Crab anatomy-Using the diagram, describe the appearance of the blue crab. Molting-Using the explanation and the photographs, describe the molting process. Make sure you click on the words, Pink, Red, and Buster to see the molting process. Then click on the word, Back, to return to the beginning of this page.

Crab page written by the Montgomery County Public School System Crab diet

Photographs to help explain some crab terms

Use the sections Feeding, Reproduction, Description

5. SHARE: Make sure you share your research with your teammates. Then collect data from your teammates on the sources they have chosen.
Photograph from the Blue Crab Archives with permission

Yikes! I have to hide before some predator sees me molting. I am shedding my old shell so I can grow a new one. But I can't protect myself very well right now. Where are the bay grasses when you want them?

Ah! There they are!

Step B
Have you ever wondered where crabs like to live? What kind of environment do they need in order to survive? You know they live in water, but what kind of water environment? After all, there is fresh water and marine. Where in the water? Do they float on top, swim around, or live on the bottom? What could happen to them if that environment was changed, damaged, ruined, or if it disappeared?
Now you will be researching the habitat of the blue crab.
1. SHARE WORKLOAD: Again, you and your teammates will choose which sites to search for information to record on your data charts.
2. SEARCH AND RECORD: Click on Crabby to bring up the information. Carefully read the information that you have located for details about the crab's habitat. If there are diagrams or pictures, then observe them for details also. Record the information on your chart. When you have completed recording what you need, then move the cursor to the Back sign to return to this section.
3. SHARE: Share the information with your teammates. Make sure you record information that your teammates have located.

Where do crabs live?

More info on where they live-scroll to Habitat

The importance of bay grasses to the Bay. Make sure you study the diagram first then write what you have learned from the diagram.

Scroll to the section on Habitat

Scroll to Ecological Role of SAV and SAV as Habitat

Step C
What could have caused the crab population to decrease? What might have happened to their habitat that would have caused them either to die off or leave? How can we undo this? What can students do to help the crab make a comeback? What can their parents do to help?
Importance of Bay Grasses

Picture used with permission from the Chesapeake Bay Foundation

One of your teammates should have seen this diagram. Before you start your research on the problems facing the crabs, study this diagram. What is this diagram explaining?
Some possible causes and solutions for the crab crisis:
   1. SHARE WORKLOAD: You and your teammates will choose which boxes to check for information to record on the second chart. You will be investigating the causes and some possible solutions to the declining crab population. Click on Crabby to see a copy of the Problems-Solutions chart that you will to construct neatly with a ruler and pencil. Make sure you include the correct headings.

    2. SEARCH AND RECORD: On the table below, click on Crabby to bring up the information. Carefully read the information that you have located for details about the causes and solutions to the decrease in the crab population. Again, make sure you pay attention to the diagrams and pictures for details. Then record that information on your PROBLEMS-SOLUTIONS chart. When you have completed recording what you need, then move the cursor to the Back sign to return to this section.
    3. SHARE: Share the information with your teammates. Make sure you record information that your teammates have located.

Excess of nutrients-Use the first two sections-Study the diagram carefully before reading the information. SAV in Decline-Scroll to section on
SAV Decline-Read the first paragraph and the last two paragraphs.

Many reasons for the drop in crab population Bay Stressors-When you get to this section, click on the diagram as instructed. Carefully observe the animated model of what causes the decline in bay life. Each member of the team should really observe this interactive diagram.

What you can do How you can help

How Excess Nutrients Harm the Bay-Scroll down to the section with the same title as this box. First study the diagram carefully. Then read the information. Scroll down to the next section and again study the diagram before reading. What you can do-Click on each section to see how you can help. Click on Back when you need to return to the list of three.

Dredging for crabs is hard work.
Students planting bay grasses.

Step D
Is the crisis caused by just one factor, or are there many causes? How can we solve that problem? What can all of us do to make sure the crabs make a comeback? How can we make sure we have crabs for our next summer outing without paying a lot of money?
Using what you have just learned about crabs, you will write a booklet to inform other fifth grade students about:

what crabs look like

how and why they molt

where they live

how they behave

why they are disappearing

what can be done to help the crab population increase

Before you begin to write, highlight the notes you want to include in your first draft.

Think about the information you have collected on the appearance, behavior, and habitat of the blue crab.

Think about what was particularly important for the crabs when they are molting.

Think about how the crabs' environment has changed and how that has affected the crabs.

Think about the factors that are causing the crab population to decline.

Think about the possible solutions that may help crab population to increase.

Think about how you will organize your information in paragraphs to make it meaningful (you should have at least 5 paragraphs). You may decide to have each paragraph on a different page in your booklet, for example.

Think about whether or not your plan will be easy to put into effect.

Think about whether or not your plan will cost a lot of money.

Think about how you can use the Student Writing Center, KidPix, or Storybook Weaver Deluxe.

Now create your booklet to inform other fifth grade students about the crabs, their appearance, behavior, habitat, which factors are causing the crab population to decline, and some possible solutions.

Return to top

Additional Resources

Crabby came from KidPix Deluxe.
The photographs came from Maryland Department of Natural Resources' web site, unless otherwise indicated .
Read the Chadwick the Crab series.
Go to the local library to ask for information on crabs in the Chesapeake Bay.

Evaluation Click on Crabby to see the scoring tool for this booklet.

Conclusion

Wow! You certainly have learned a lot about crabs. As you were researching for this project, you discovered that crabs play an important part in the economy of Maryland. They are also important to the health of the Bay. Scientists have learned to pay attention to the health of the invertebrates. When they become sick or start to disappear, then there are problems with the habitat.

Extension
Are the water men affected by the problems facing the crabs? What organizations are helping to solve these problems? What is the state of Maryland doing to solve these problems?
You may want to contact the following agencies and organizations for further information.

CBF or Chesapeake Bay Foundation.
MDNR or Maryland Department of Natural Resources

You might even want to start saving news articles on crabs from your newspaper and place them in a scrapbook to help you keep track of what is happening in the crab world.

Perhaps you could get some friends involved in a raising bay grasses project. Each summer, classes sign up to be part of the Bay Grasses in Classes. The students are raising bay grasses that will later be planted in areas that desperately need the bay grasses. They also learn more about plants from experiments they conduct.

Ask your parents if you can use the Internet and look up the Blue Crab Archives and other related links. Have your parents be part of your continued investigation.

Charts

Name _______________________________ Date __________

Appearance, Behavior, and Habitat of the Blue Crab

Appearance	Behavior	Habitat

Name _______________________________________ Date __________

Problems and Solutions

Problems	Solutions

Maryland Learning Outcomes

Science Environmental Issues
6.5.5 Explain that decisions influencing the environment may have benefits, drawbacks, and unexpected consequences no matter how carefully the decisions are made.
6.3.2 Explain that organisms can survive only in environments in which their needs (e.g. , food, water, and habitat) can be met.
Language Arts-Writing
3.5.4 Write informational reports for an intended audience and purpose that frame a key question, present a literal understanding of the topic and include facts and details that illuminate the main idea.

Student Outcomes
Writing- Students will write a report to inform.

Reading- Students will read to be informed as well as read to perform a task.

Science-Describe a science related issue that is relevant to you and using scientific knowledge, make a decision regarding the issue. Describe to others how your knowledge of science helped you reach your decision.

Technology Indicator- Efficiently use electronic information sources for accuracy, relevance, appropriateness, comprehensives, and bias of electronic information sources. 5.3

Dimensions of Learning

DOL 1-Teachers need to help students perceive tasks as valuable.

DOL 2-To acquire new declarative knowledge, students need to organize it visually through graphic organizers, flow charts, and other schematic tools.

DOL 3-Students do not truly internalized and own essential knowledge unless they engage in activities to help them extend and refine their understanding and use of it.

DOL 4-Problem-solving identify a real world problem, consider alternative solutions, and supporting a final set of solutions with concrete evidence.

DOL 5-Students think critically, creatively, and self-regulating.

Created by L. Jean Everhart
Updated August 2002

Identifying the blue crab	Crab anatomy-Using the diagram, describe the appearance of the blue crab.	Molting-Using the explanation and the photographs, describe the molting process. Make sure you click on the words, Pink, Red, and Buster to see the molting process. Then click on the word, Back, to return to the beginning of this page.
Crab page written by the Montgomery County Public School System	Crab diet	Photographs to help explain some crab terms
	Use the sections Feeding, Reproduction, Description

Excess of nutrients-Use the first two sections-Study the diagram carefully before reading the information.	SAV in Decline-Scroll to section on SAV Decline-Read the first paragraph and the last two paragraphs.
Many reasons for the drop in crab population	Bay Stressors-When you get to this section, click on the diagram as instructed. Carefully observe the animated model of what causes the decline in bay life. Each member of the team should really observe this interactive diagram.
What you can do	How you can help
How Excess Nutrients Harm the Bay-Scroll down to the section with the same title as this box. First study the diagram carefully. Then read the information. Scroll down to the next section and again study the diagram before reading.	What you can do-Click on each section to see how you can help. Click on Back when you need to return to the list of three.