Image of crab traps on the dock of the Chesapeake Bay

All About Crabs - Teacher's Guide

Grade 3

This lesson focuses on two main ideas:

The historical and ongoing importance of oysters and crabs to the Chesapeake Bay and our region’s economy
How changes to the Chesapeake Bay have led to changes in the blue crab population

Procedure

INTRODUCTION (15 minutes)

Read the introduction to students and review new vocabulary. Students will watch the “Water’s Edge: Black Watermen of the Chesapeake” video. After the video, have a discussion around the essential questions and thinking questions aligned to the topic and video. Discuss the career connections related to the Chesapeake Bay and blue crab harvesting with students.

EXTENSION (15-30 minutes)

Complete extension activities with students, as you see fit.

ASSESSMENT (15 minutes)

Have students apply their newfound knowledge by completing a Summative CER on the lesson using evidence from the video and activities as support.

REFLECTION (10 minutes)

Have students complete a reflection.

Standards

NGSS Performance Expectation

3-LS2-1 Ecosystems: Interactions, Energy, and Dynamics
Construct an argument that some animals form groups that help members survive.

Science and Engineering Practices
Engaging in Argument from Evidence
Engaging in argument from evidence in 3–5 builds on K–2 experiences and progresses to critiquing the scientific explanations or solutions proposed by peers by citing relevant evidence about the natural and designed world(s).
- Construct an argument with evidence, data, and/or a model
Disciplinary Core Ideas
LS2.D: Social Interactions and Group Behavior
- Being part of a group helps animals obtain food, defend themselves, and cope with changes. Groups may serve different functions and vary dramatically in size.
Crosscutting Concepts
Cause and Effect
- Cause and effect relationships are routinely identified and used to explain change.

Maryland Environmental Literacy Standard

Standard 2
Human Dependence on Earth Systems and Natural Resources:
Environmentally literate students construct and apply understanding of how Earth’s systems and natural resources support human existence.

Summative CER

Option 1:

Construct an argument around the importance of blue crabs for both our region’s economy and the entire Chesapeake Bay ecosystem. Use evidence and reasoning from the videos and activities to support your argument.

Option 2:

Develop an explanation for how changes in the Chesapeake Bay have led to changes in blue crab populations. Use evidence and reasoning from the videos and activities to support your explanation.

Reflection Questions

Why are oysters and crabs so important to us? How do they help the economy?
What has changed about the Chesapeake Bay over time? What has changed in regard to the blue crab populations over time? What is the relationship between these changes?

Summative CER Rubric

No Response Score Point 0	Not There Yet Score Point 0.5	Beginning To Score Point 0.75	Yes Score Point 1.0
The claim is missing	The claim is incorrect or irrelevant.	The claim partially takes a position on the topic or issue addressed within the prompt.	The claim takes an appropriate position on the topic or issue addressed within the prompt.
There is no type of evidence in the response	The evidence is irrelevant or does not support the claim.	The evidence partially supports the claim and demonstrates some understanding of the topic or text, using appropriate sources.	The evidence supports the claim and demonstrates a strong understanding of the topic or text, using appropriate sources.
There is no use of words, phrases, and clauses to create cohesion and to clarify the relationship between the claim and evidence.	Use of words, phrases and clauses fail to show or explain any relationship between the claim and evidence.	Scientific words, phrases, and clauses used lack cohesion but partially clarify the relationship between the claim and evidence.	Appropriate scientific words, phrases, and clauses are used to create cohesion and to clarify the relationship between the claim and evidence.