Mighty Mangroves: Exploring the Role of Mangrove Forests in Coastal Ecosystems

Summary

Students will learn about mangrove forests, understand their importance to coastal ecosystems, and play a game about environmental sustainability.

Coin Type(s)

  • Quarter

Coin Program(s)

  • America the Beautiful Quarters

Objectives

  • Students will learn what a mangrove forest is and why they are important to the ecosystem of the U.S. Virgin Islands.
  • Students will be able to name the benefits of mangrove forests.
  • Students will be able to identify threats to mangrove forests.
  • Students will play a game using information learned about mangrove forests.

Major Subject Area Connections

  • Language Arts
  • Science

Minor/supporting Subject Area Connections

  • Art

Grades

  • 3rd
  • 4th
  • 5th

Class Time

  • Sessions: Three
  • Session Length: 30-45 minutes
  • Total Length: 46-90 minutes

Groupings

  • Whole group
  • Small groups
  • Individual work

Background Knowledge

Students will have a basic knowledge of the following:

  • Ecosystem
  • Habitat
  • Species
  • U.S. Virgin Islands
  • Tropical climate
  • Coastal ecosystem

Terms and Concepts

  • Mangrove
  • Mangrove forests
  • Fringed
  • Brackish
  • Prop roots
  • Propagules
  • Detritus
  • Dredging 

Materials

Preparations

  • Bookmark the links above in advance.
  • Make copies of the worksheets about American Samoa.

Worksheets and Files

Lesson Steps

Session One

Essential Questions: What is a mangrove? Where do mangroves grow? What are some characteristics of mangroves?

  1. Show students the quarter design, including the reverse or tails side, found on the U.S. Mint's website: www.usmint.gov/coins/coin-medal-programs/america-the-beautiful-quarters/salt-river-bay-national-historical-park-and-ecological-preserve. Explain that as part of the America the Beautiful Quarters® Program, the U.S. Mint features national parks and historical sites on quarters that are specific to a state, territory, or district. In 2020, the U.S. Virgin Islands quarter highlights the Salt River Bay National Historical Park and Ecological Preserve. The park is located on St. Croix in the U.S. Virgin Islands.
  2. Ask students to guess which type of plant is featured on the coin. Explain that this is a mangrove tree. Many trees that grow together are known as mangrove forests. They play a very important part in the coastal ecosystem in the U.S. Virgin Islands. The Salt River Bay National Historical Park and Ecological Preserve holds some of the largest remaining mangrove forests in the Virgin Islands.
  3. Explain to students that they are going to learn all about mangrove forests and the services they provide.
  4. Show students additional pictures of mangroves from the NPS website for Salt River Bay National Historical Park and Ecological Preserve (www.nps.gov/sari/index.htm); Mangrove and Salt Marshes (www.nps.gov/subjects/oceans/mangroves.htm); Red Mangroves (www.nps.gov/bicy/learn/nature/red-mangrove.htm) or other online sources. Point out interesting characteristics about mangroves to help guide students' thinking (i.e., where it grows, what the roots look like, what type of water it grows in, etc.).
  5. As a warmup activity, ask students to make predictions about mangroves based on their observations.
    • If teaching in person, have students write their predictions in the Predictions column of the "Making Predictions Graphic Organizer" worksheet.
    • If teaching remotely, have students create their own graphic organizer in a journal or notebook using the Graphic Organizer worksheet as a guide. After writing their predictions, allow students to share their predictions.
  6. Show the NPS video, "Success at Salt River Bay NHP&EP planting red mangroves with STEM students: one year later": www.youtube.com/watch?v=G_xI7xJXC7A. Ask students to share what they learned about mangroves.
  7. Explain that mangrove trees that grow together are called mangrove forests. Mangrove forests play an important role in a coastal ecosystem. Review the following information with students:
    • A mangrove is a small tree or shrub that grows in shallow water along the coastlines in warm, tropical climates.
    • Mangrove forests grow in tropical or subtropical regions all over the world, including the U.S. Virgin Islands. On St. Croix, Salt River Bay is fringed – or bordered – by mangrove forests. There are 3 main species in Salt River Bay: red mangroves, white mangroves, and black mangroves. The quarter features a red mangrove tree.
    • Mangroves can grow in saline water (saltwater) or brackish water (a mixture of fresh water from any source like a river and salt water from the sea).
    • Mangroves are "landbuilder communities" – they extend the shoreline through their system of roots, called "prop roots".
    • The roots of mangroves are special. Like other plants, they need oxygen to survive, but there is no oxygen in the mud or soil where the roots are. So, mangroves have developed roots that grow from the ground upwards and even beyond the surface of the sea. This allows them to breathe and get the oxygen they need.
    • Mangrove seeds are also unique. The seeds develop into a seedling with leaves and roots while still on the mature mangrove tree. The seedlings – called propagules – will stay on the adult tree and grow to a certain size. Then, they drop into the water and float until they reach water that is shallow enough for the roots to penetrate the mud. These seedlings can travel far distances and survive waves and tide changes.
    • Mangrove forests provide many benefits:
      • Provide a habitat for hatchling sea turtles or a "nursery" for vulnerable young fish, shrimp, and crustaceans that later move out to coral reefs or to sea
      • Provide food for tiny marine animals (i.e., leaves and twigs are broken down and eaten by small organisms)
      • Provide nesting areas and shelter for coastal birds
      • Prevent coastline erosion
      • Clean the water (i.e., trap and cycle pollutants and chemicals)
      • Protect uplands from storms, winds, waves, and floods
  8. Using the Making Predictions Graphic Organizer worksheet or their own journal/notebook entry, have students check their original predictions and fill in the "Fact Check" column with new information they learned. Ask for students to share whether their predictions were correct and what they learned.
  9. Next, each student will create their own mangrove tree. Using the Salt River Bay National Historical Park and Ecological Preserve quarter design and mangrove images as a guide, demonstrate to students how to create a model of a mangrove tree using craft materials available. The model should show its roots, trunk, leaves, and canopy. If students get done early, have students research and create models of some of the animals that live in, on, or around the mangrove tree (e.g., fish, shrimp, algae, bees, birds, etc.).
    • If teaching in person, have students make their mangrove model using various craft supplies (e.g., pipe cleaners, construction paper, paper towel rolls, tissue paper, glue, tape, scissors, paper mache, brown/black/white paint, etc.).
    • If teaching remotely, have students find materials around their house that they can use (e.g., cardboard tubes from paper towel or toilet paper rolls, straws, napkins, building blocks, play dough, paper, cardboard, newspaper, etc.).
  10. Once students complete their mangrove tree model, have them create another model of a tree that is located near their house or neighborhood. Ask the students to explain how the models are similar and how they are different.

Session Two

Essential Questions: What role do mangrove forests play in the ecosystem of the U.S. Virgin Islands? Why are they important to preserve and protect?

  1. Review with students what a mangrove is and the key characteristics of mangrove forests.
  2. Create a T-chart on a projector, smartboard, whiteboard and/or via a digital presentation. On side of the T-chart, write "Environmental Benefits". On the other side, write "Human Benefits". Explain to students that mangrove forests play a very important role in the environment as well as human communities. They provide food, shelter, and protection for animals and humans.
  3. Re-watch the NPS video, "Success at Salt River Bay NHP&EP planting red mangroves with STEM students: one year later": www.youtube.com/watch?v=G_xI7xJXC7A. Ask students to name some of the benefits of mangroves that were discussed in the video (listed below) or from what they learned in Session One. After each benefit is listed, ask if it is a human benefit or an environmental benefit. Write each benefit under the correct column in the T-chart. Examples of responses can include:
    • Environmental Benefits
      • Roots provide habitats or a "nursery" for young fish, shrimp, and crustaceans that later move out to coral reefs or to sea
      • Leaves and branches provide habitats for birds, bees, insects, and other wildlife
      • Decayed leaves and/or twigs – called detritus – are broken down and eaten by small organisms, which in turn, become food for larger organisms
      • Protects the coastlines from storms, erosion, and floods
      • Controls stormwater / runoff from the land by capturing sediment and/or pollutants to help clean the water
      • Protects coral reefs from too much sediment from runoff
    • Human Benefits
      • Protects areas of human settlement from heavy storm surge (e.g., winds, waves) from seasonal hurricanes
      • Protects areas of human settlement from erosion
      • Provide a rich source of fishery products (e.g., fish, shellfish)
  4. Let the students know that they will be creating a "Mighty Mangrove" tree diagram. Use the pictures and/or coin design as a guide.
    • If teaching in person, break students into small groups. Allow them to draw the roots, trunk, and branches of a mangrove tree on a large sheet of paper or poster.
    • If teaching remotely, instruct students to draw their own roots, trunk, and branches of a mangrove tree on a piece of paper or another medium (e.g., a large brown paper grocery bag).
  5. Using the T-chart as a guide, instruct students to choose a benefit that they think is important. Using the Benefits Leaf Template worksheet as a guide, model for students how to write a sentence explaining why mangrove forests are important using the benefit they selected.
    • If teaching in person, have students cut out a leaf from construction paper and re-write their sentence on the leaf.
    • If teaching remotely, have students draw a leaf on a piece of paper, re-write their sentence, then cut it out and color it.
  6. Instruct students to either tape or glue their leaves onto the tree branches. Allow students to continue to create more leaves that describe additional benefits to fill out the tree more.
    • If teaching in person, take turns presenting each group's tree to the class.
    • If teaching remotely, have students show their tree to an adult and/or virtually.

Session Three

Essential Questions: What threats do mangrove forests face? What can I do to help protect and preserve mangrove forests?

  1. Review what mangroves are, why they are important, and what benefits they have for both the environment and human communities.
  2. Explain that many mangrove forests face threats from a variety of natural and human causes.
    • Natural causes can include hurricanes, heavy storms, rising sea levels, and pests or diseases.
    • Human causes can include dredging – or the removal of material from the bottom of lakes, rivers, and other bodies of water; construction of human settlements (e.g., housing projects, marinas); pollution; global warming and climate change.
  3. Explain that mangrove forests are an important part of the coastal ecosystem. It is important to protect, preserve, and restore mangrove forests to ensure they are available for future generations. Some ideas for ways to protect and restore mangrove forests include:
    • Educate others about the importance of mangrove forests
    • Keep the water clean (e.g., do not dump waste into the sea)
    • Help to plant new mangroves
    • Get involved in your local community about mangrove conservation
    • Pick up trash or debris around your local community
    • Recycle plastics to prevent them from entering oceans
  4. Explain to students that they will be playing the Mangrove Maze game. this game, they will learn about the different threats that face mangrove ecosystems, as well as different ways to help protect them. Players begin at the "START" block, moves 1-2 spaces at a time (depending on flip of a coin) and follows the directions on the game board. A player wins once they reach the "END" block.
    • If teaching in person, group the students into pairs and provide each group with one version of the game board, Mangrove Maze Game worksheet, a coin with different heads/tails, and two small toys or objects to serve as player pieces. With their partner, the students will take turns flipping a coin to move their piece: "heads" means the player moves one space and "tails" means the player moves two spaces. The players will follow any instructions on the space they land. Not all spaces have instructions. The first player to reach "END" wins the game.
    • If teaching remotely, encourage the student to play the game with a friend or family member. If this is not possible, the game can still be played with one player. For the game board, the student can either print out the Mangrove Maze worksheet or create their own board game by drawing 25 spaces and numbering them #1-25. Once they land on a spot with a specific number, they can use a digital version of the Mangrove Maze Game worksheet to locate the specific number and read the corresponding scenario. The student will also need to collect two small objects or toys to serve as player pieces, as well as a coin. If a coin is not available, they can cut out a piece of paper with "1" on one side and "2" on the other. A "heads" or the number "1" means the player moves one space; a "tails" or the number "2" means the player moves two spaces. The player to reach "END" first wins the game.
  5. After playing the game, ask students to reflect on what they learned. This can be done verbally or using the Reflection Activity worksheet.

Differentiated Learning Options

  • Group students together during the worksheet exercise
  • Have students present their written response(s) orally.
  • Allow students to use a scribe or computer to complete the graphic organizer, research, and/or questions. 

Enrichments/Extensions

  • Have students research different animals that use mangrove forests as habitats, and research key facts about each animal, including what it eats and what its predators are.
  • Using the research for animals that use mangroves as a habitat, construct a food web that shows the entire food chain for animals who rely on mangrove forests. Reflect
  • what would happen if the mangrove forest habitat was to go away.
  • Have students create another board game and/or research more questions about the mangrove forests and/or other types of animals that are of interest to them.
  • Have students create their own questions about mangrove forests and challenge a classmate.
  • Have the winner of each game play a winner of the other game and keep playing until one student wins.
  • Have students create a poster that outlines the information that they learned about mangrove forests, including benefits, threats, and ways to help protect them.

Assess

  • Evaluate the research, ability to answer questions, and students' participation to assess how well the students have met the lesson objectives.

Common Core Standards

National Common Core State Standards (NCSS)

English Language Arts (ELA)

Grade 3:

  • ELA-LITERACY.RI.3.1: Ask and answer questions to demonstrate understanding of a text, referring explicitly to the text as the basis for the answers.
  • ELA-LITERACY.RI.3.4: Determine the meaning of general academic and domain-specific words and phrases in a text relevant to a grade 3 topic or subject area.

Grade 4:

  • ELA-LITERACY.RI.4.1: Refer to details and examples in a text when explaining what the text says explicitly and when drawing inferences from the text.
  • ELA-LITERACY.RI.4.4: Determine the meaning of general academic and domain-specific words or phrases in a text relevant to a grade 4 topic or subject area.

Grade 5:

  • ELA-LITERACY.RI.5.4: Determine the meaning of general academic and domain-specific words and phrases in a text relevant to a grade 5 topic or subject area.
  • ELA-LITERACY.RI.5.7: Draw on information from multiple print or digital sources, demonstrating the ability to locate an answer to a question quickly or to solve a problem efficiently.

Writing

Grade 3:

  • ELA-LITERACY.W.3.7: Conduct short research projects that build knowledge about a topic.
  • ELA-LITERACY.W.3.8: Recall information from experiences or gather information from print and digital sources; take brief notes on sources and sort evidence into provided categories.

Grade 4:

  • ELA-LITERACY.W.4.7: Conduct short research projects that build knowledge through investigation of different aspects of a topic.
  • ELA-LITERACY.W.4.8: Recall relevant information from experiences or gather relevant information from print and digital sources; take notes and categorize information and provide a list of sources.

Grade 5:

  • ELA-LITERACY.W.5.7: Conduct short research projects that use several sources to build knowledge through investigation of different aspects of a topic.
  • ELA-LITERACY.W.5.9: Draw evidence from literary or informational texts to support analysis, reflection, and research.

National Standards

Discipline: Science

Domain: NGSS-4-6 Next Generation Science Standard

Cluster: Earth and Space Science Disciplinary Core Concepts

Grade(s): Grades 4–6

Standards:

  • ESS2.D: Weather and Climate
  • ESS3.C: Human Impacts on Earth Systems

Discipline: Science

Domain: NGSS-4-6 Next Generation Science Standard

Cluster: Life Science Disciplinary Core Concepts

Grade(s): Grades K–12

Standards:

  • LS1.A: Structure and Function
  • LS2.A: Interdependent Relationships in Ecosystems
  • LS2.C: Ecosystem Dynamics, Functioning, and Resilience