Uncovering How Eelgrass Protects Washington Waters from Ocean Acidification

Amanda Arnold; Katharine Byrnes; and Elizabeth Matteri

Overview

While climate change is a global issue, using a local example can help make the concepts seem less faraway and abstract.  Climate change is affecting the environment and the people living in Washington State.  This curriculum gives students a way to connect with citizen science data collection in nearshore ecosystems to understand the role of eelgrass in moderating the effects of increasing acidity that accompanies increased atmospheric CO2 concentrations.  These connections can help empower students with ways they can participate in solutions to climate change as they face the global and local impacts.

The three modules in this curriculum were developed by Lizzy Matteri, Katie Byrnes, and Amanda Arnold, all graduate students in the School of Marine and Environmental Affairs at the University of Washington, with advising by Professor Mark Windschitl (UW College of Education), and in partnership with the Washington Department of Natural Resources (DNR).  Each module contains 3 lessons, each is accompanied by presentation slides and a lesson overview. Hands-on activities, videos, worksheets, and other materials are also included.   This project fulfilled the capstone requirement for all three creators’ Graduate Certificate in Climate Science, and the curriculum was presented in a virtual teacher workshop that instructed teachers on the content of the lesson and how to adapt it for their own classrooms.  Read about this teams experience with curriculum development in the blog post: “Lessons Learned: How Can We Connect Middle School Students to Climate Change and Ocean Acidification”

 

Grade Level: 7th and 8th grade

Meets Next Generation Science Standards MS-LS-2, MS-LS2-1, MS-LS2-3, and MS-LS2-4.

Basic Unit Outline:

Curriculum Introduction and Prerequisites

Curriculum Introduction and Prerequisite Overview

Prerequisites: What should students already know?

  • Students should have a basic understanding of photosynthesis. Photosynthesis is revisited in this unit, but how it occurs is not explained.
  • Students should have a basic understanding of climate change, specifically they should know that CO2 is a greenhouse gas, and what it means to be a greenhouse gas.
  • Students should have a basic understanding of chemistry: e.g. an understanding of what molecules are, the differences between types of matter, and polarity.

Module 1: Eelgrass Environments and Ecosystem Connections in WA

Focuses on introducing nearshore ecosystems in Washington and is designed to help students think critically about the type of habitat and many ecosystem services that eelgrass provides.

Module 2: Ocean Acidification

Dives into ocean acidification and asks students to consider how carbon dioxide interacts with the ocean, and how eelgrass can impact this relationship through carbon dioxide uptake and sequestration.

Module 3: Community Science and Local Impacts

Students apply what they have learned about the nearshore eelgrass ecosystem and ocean acidification to determine the cascading impacts of ocean acidification on the nearshore environment and ocean as a whole.

Background Information for Teachers

What is Ocean Acidification?

Ocean acidification is a term that describes the drop in pH (increase in H+ ions) that occurs when  CO2 dissolves in ocean water. H+ ions readily bond with CO32- ions (one form of dissolved CO2), leading to another effect of ocean acidification — reducing the amount of CO32- ions available to form solid calcium carbonate(CaCO3). As CaCO3 is a crucial molecule in developing skeletons and shells, ocean acidification can have an adverse effect on many marine organisms, including corals and shellfish.

Read more about Ocean Acidification here.

What is eelgrass and why is it important?

Eelgrass is a flowering marine plant that is identified by its long, ribbon-like leaves. It grows in muddy or sandy substrate in shallow coastal waters, including nearshore ecosystems in and around Puget Sound. Eelgrass is a primary producer, so it is the foundation of the food web in the ecosystems in which it is found, playing a crucial role in providing stability to the trophic system. As a photosynthesizing organism, eelgrass absorbs COfrom the water, helping to  increase the pH of the surrounding waters.  In this way, eelgrass directly supports the ecosystem and is able to reduce the effects of ocean acidification. The original research that showcases the potential of eelgrass to mitigate ocean acidification can be found here.

What is Project ANeMoNe?

In 2015 Washington’s Department of Natural Resources (DNR) created the Acidification Nearshore Monitoring Network (ANeMoNe) to broaden the state’s understanding of ocean acidification.1 Two of the project’s original goals included monitoring acidification and warming in Washington waters and testing management strategies for enhancing ecosystem resilience.1 The project expands upon a study conducted in collaboration with the University of Washington, which determined that photosynthesis from eelgrass meadows can increase the local pH and thereby counteract some of the negative impacts of ocean acidification.2 These ecosystems and their inhabitants (especially shellfish) are critical for ecological, commercial, and cultural reasons.2  DNR is responsible for the management of 2.6 million acres of Washington’s aquatic lands and therefore has a vested interest in learning more about and protecting nearshore ecosystems.

By 2018 the ANeMoNe project expanded to include community volunteers, dubbed Site Guardians, who help maintain the various project sites and participate in experiments and data collection.3 The inclusion of community scientists helped DNR move toward another goal: increasing public awareness about ocean acidification and its impacts in Washington waters. Recently DNR was awarded a grant to develop curricula for local schools about climate change and ocean acidification in Washington state, to further public awareness and student engagement.

The purpose of this project is to develop an engaging and interactive climate science curriculum focused on nearshore eelgrass ecosystems in Washington state.

Read more about Washington DNR and its projects here and here.

References

  1. Washington State Department of Natural Resources. Engaging the Public With Ocean Acidification Science.
  2. Washington State Department of Natural Resources. Eelgrass and Ocean Acidification.
  3. Washington Office of the Superintendent of Public Instruction (n.d.). Climate Science Learning. Retrieved from https://www.k12.wa.us/student-success/resources-subject-area/science/climate-science-learning

Module 1: Eelgrass Environments and Ecosystem Connections in Washington

Lesson 1A: Eelgrass and Photosynthesis

Students review photosynthesis and infer and explore how photosynthesis by underwater plants affects ocean chemistry.

NGSS Standards:

  • MS-LS-2: Construct an explanation that predicts patterns of interactions of organisms across multiple ecosystems.
  • MS-LS2-3: Develop a model to describe cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
Learning Objectives:
  • Using knowledge of terrestrial plants and photosynthesis, students can hypothesize the impact of aquatic-plants on the ocean.
  • Students apply the concept above to deduce the impact of photosynthesis by eelgrass on nearshore ecosystems.
Teacher Resources: 

Materials:

  • Pens/pencils
Lesson 1A Overview:
    1. Introduce the lesson with a review of photosynthesis using the Lesson 1A slides.
    2. Activity 1: Photosynthesis Inputs and Outputs
      • Hand out materials for Activity 1
      • Begin a class discussion about what in our terrestrial environment photosynthesizes and what students think are some of the inputs and outputs of this process.
      • Give students 10 minutes to fill in the worksheet with their guesses for the inputs and outputs of photosynthesis. Have students illustrate these concepts.
      • Come together as a class to share these ideas and correct students’ worksheets with the correct inputs and outputs.
    3. Return to the Lesson 1A slides, transition to an introduction to eelgrass.
      • Introduce the idea that photosynthesis is a process done by eelgrass.
      • Identify the two species of eelgrass in Washington. Mention that one species is native to the state and one is non-native that became abundant after being introduced.
        • Note: Instructors could add a lesson on native and non-native species as it is not explored in any depth in this lesson.
    4. Compare and contrast terrestrial and aquatic photosynthesis.
      • Begin to elicit student ideas about how processes we are already familiar with (i.e. terrestrial photosynthesis) are occurring underwater and what the implications or importance of these processes may be.
        • Note: Lesson 2 dives into ocean acidification, so here we are just beginning to think about these processes.
    5. Activity 2: Compare and Contrast
      • Students fill out a Venn diagram comparing what they know about terrestrial photosynthesis and photosynthesis in eelgrass. Invite students to think about the implications of photosynthesis by underwater plants to rising atmospheric CO2 concentrations and climate change.
      • Quick exit question to elicit student ideas about the implications of these processes, preparing them for coming lessons.
    6. Finish slides and have students fill in exit questions prompted by the “Thinking Ahead” slide.

Lesson 1B: Nearshore Eelgrass Ecosystems and the Importance of Community Science

Students gain an understanding of the nearshore zone and the importance of eelgrass in this type of ecosystem. Students are introduced to the role of ANeMoNe and community science in monitoring the nearshore zone.

NGSS Standards:

  • MS-LS2-2: Construct an explanation that predicts patterns of interactions of organisms across multiple ecosystems.
  • MS-LS2-3: Develop a model to describe cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
Learning Objectives:
  • Students are able to describe the nearshore zone and its environmental importance.
  • Students understand what community science is and its role in ANeMoNe.
Teacher Resources: 
Materials:
  • Pens/pencils
Lesson 1B Overview:
  1. Begin this lesson by showing students a map of the nearshore ecosystems in Washington (slide 4 in Lesson 1B slide deck).
    • Students should understand that the nearshore zone is a part of the ocean system as a whole, but constitutes a specific area. This will aid in their understanding of the distinct ecosystem attributes and functions of this area.
  2. Show ANeMoNe video.
  3. Outline the ecosystem functions that this area provides, making the connection to eelgrass, which was introduced in Lesson 1A.
    • Introduce some of the services eelgrass provides. We will return to this in greater depth in the subsequent lesson (1C) when building food webs and making connections between species.
  4. Transition to discussing the work ANeMoNe does and the link to the nearshore zone.
    • Founded to expand understanding of ocean acidification in Washington state.
      • Note: Ocean acidification will be discussed in detail in Lessons 2A-C.
    • Emphasize that one of the main goals of the program and the motivation for this module is the desire to increase public engagement with ocean acidification through volunteers and education.
  5. Discuss community science and how students can get involved in local scientific research
    • Introduce the concept of non-professional scientists who volunteer to conduct scientific research
    • Highlight that this is a way students can get involved in scientific research in their community
  6. Show additional ANeMoNe pictures.
  7. Have students fill out exit questions.

Lesson 1C: Species Connections in Eelgrass Ecosystem

Students describe basic interactions among species in eelgrass ecosystems and hypothesize how these interactions may change with altered oceanic conditions.

NGSS Standards:

  • MS-LS-2: Construct an explanation that predicts patterns of interactions of organisms across multiple ecosystems.
  • MS-LS-4: Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
Learning Objectives:
  • Students can describe species in eelgrass ecosystems and discuss their basic interactions.
  • Students can describe how these species interactions may change with altered oceanic conditions (due to ocean acidification).
Teacher Resources: 
Materials:
Lesson 1C Overview:
    1. Begin with a review of what we learned about eelgrass in Lesson 1A.
    2. Discuss the type of habitat eelgrass provides.
    3. Activity part 1: Which species live in eelgrass ecosystems?
      • In groups, students answer questions in the Lesson 1C worksheet about where eelgrass ecosystems are located and the habitat they can provide. Using this information, they should hypothesize about what species are likely to be found there.
      • Groups share their answers with the class and a class list of species is compiled.
    4. Hand out packs of species cards to each group and give a brief description of all species. These cards will show key species found in the eelgrass ecosystem.
    5. Activity part 2: Species Cards
      • Hand out species cards to each group.
      • Briefly introduce the species on the cards. Using two of the cards, show an example of which species eats which species to start the students thinking about these types of interactions.
      • Students should work together to sort out interactions among various species to create a food web showing the flow of energy.
    6. Discuss food webs as a class, finish by having students fill out exit questions.

Module 2: Ocean Acidification

Lesson 2A: Introduction to Ocean Acidification

Students develop new knowledge and apply existing knowledge of how CO2 is increasing in the atmosphere and how it interacts with our oceans.

NGSS Standards:

  • MS-LS2-3: Develop a model to describe cycling of matter and flow of energy among living and nonliving parts of an ecosystem. The living aspect of this standard will be achieved in conjunction with the shelled organism lessons.
  • MS-LS2-4: Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
    • Emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems. This standard will be achieved in conjunction with the shelled organism and data lessons.
Learning Objectives:
  • Students review the anthropogenic (human) factors contributing to increased CO2 levels in the Earth’s atmosphere.
  • Students understand that CO2 in the atmosphere dissolves into the Earth’s oceans, and how agitation impacts this process.
Teacher Resources: 
Materials:
  • Pens/pencils
  • Two liter bottle of soda, label removed
Lesson 2A Overview:
  1. Introduce the lesson by reviewing the Greenhouse Effect and how humans are impacting the amount of greenhouse gases in the atmosphere using the Lesson 2B slides.
  2. Activity 1: Graph Interpretation Worksheet
    • Have students interpret graphs regarding the history of CO2 in the Earth’s atmosphere.  They should provide a reason for the inflection point at the time of the industrial revolution. Use the provided worksheet. This activity should take approximately 15-20 minutes.
  3. Return to the slides to transition into thinking about how COis impacting the ocean.
  4. Activity 2: Soda Demo
      • This demo should help students conceptualize how gases can dissolve in liquids. This activity should take no more than 5 min.
        1. Ask students how soda or soda water differs from regular water.
        2. Ask students if they see any bubbles in the unopened bottle of soda.
        3. Slowly uncap the bottle and ask the students what they see.
        4. Slowly recap the bottle. What happens now?
        5. Ask students what the bubbles are made up of (hint for students: we sometimes call soda carbonated beverages).
        6. Ask students if any have or know about soda machines. If yes, how do they work?
        7. Return to presentation and explain more about CO2 dissolving into water.

Lesson 2B: Acids and Bases

Students develop an understanding of the different properties of acids and bases. Students begin to make the connections between negative impacts of increased atmospheric CO2.

NGSS Standards:

  • MS-LS2-3: Develop a model to describe cycling of matter and flow of energy among living and nonliving parts of an ecosystem. The living aspect of this standard will be achieved in conjunction with the shelled organism lessons.
  • MS-LS2-4: Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
    • Emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems. This standard will be achieved in conjunction with the shelled organism and data lessons.
Learning Objectives:
  • Students develop an understanding of the pH scale, and the properties of acids and bases.
  • Students learn how scientists use the pH scale to measure ocean acidification.
  • Students understand that small changes in the scale represent a much larger shift in the chemical balance.
Teacher Resources: 
Materials:
  • Pens/pencils
  • Safety goggles
  • Bromothymol blue
  • Tap water
  • Drinking straws (1 per student)
  • Clear paper cups or beakers (1 per student groups)
  • Container for used straws
  • Container for waste water
Lesson 2B Overview:
  1. Introduce the lesson topic and overarching question.
  2. Activity 1: Ted Ed Video
  3. Discuss the properties of acids and bases using the Lesson 2B Slides.
  4. Activity 2: Characteristics of Acids and Bases
    • If not already completed, have students fill in the final question on their worksheet by brainstorming about which common household items could be acids or bases.
  5. Return to the slides and introduce how scientists measure pH and how pH changes in the ocean.
  6. Activity 3: Bromothymol Blue Model
    • This activity should tie everything together between Lesson 2A and Lesson 2B. Students will increase the amount of CO2 in their model ocean and observing the changes in acidity through an indicator. Blowing into the straws at different speeds will act as “wind” and agitate the bromothymol solution. Students should observe that blowing harder changes the indicator color more quickly.
      • Break students up into groups of 2 or 3. Each group will need two cups containing bromothymol blue solution, as well as straws and safety goggles for each student.
      • Instruct the students to use their straws to blow into one of their cups quickly and to use their straws to blow into the other cup slowly. What are students noticing? Are there changes depending on the speed (agitation!) at which they are blowing into the water.
      • Come together as a class. What did students observe?

Lesson 2C: Impact of increased CO2 in the ocean on organisms with carbonate structures

Students learn how shells form, why ocean acidification can impact this process, and how acidity can corrode the shells that are able to form.

NGSS Standards: 

  • MS-LS2-3: Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
    • Emphasis is on describing the conservation of matter and flow of energy into and out of various ecosystems, and on defining the boundaries of the system
  • MS-LS2-4: Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
    • Emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems.
Lesson Objectives:
  • Students hypothesize how two shells would differ after a few days if one was in purified water and one was in slightly acidic water.
  • Students explain how organisms with carbonate structures are impacted by ocean acidification.
Teacher Resources: 
Materials:
  • Pens/pencils
  • 3 glass/clear containers
  • Labels and markers
  • Cup and teaspoon measurements
  • Shells (alternate: chalk)
  • Water
  • Salt
  • Vinegar
Lesson 2C Overview:
  1. Introduce the lesson topic using the Lesson 2C slides.
  2. Set up Activity: Shell experiment (see worksheet)
    • Students should form hypotheses about the impact of increased levels of CO2 on various organisms.
      • Write initial hypotheses down
  3. Return to the presentation to discuss how shells form.
    • Explain that the Calcium Carbonate formed by marine organisms comes in different forms.  Two common forms are aragonite and calcite, and aragonite is more soluble than calcite.
    • Discuss how carbonate ions impact shell formation
  4. Re-visit Activity:
    • Re-visit the written hypotheses – students should assess if they need to make any changes to their initial hypothesis.
    • Brainstorm how this experiment would affect other shelled organisms.
      • I.e. Mussels, urchins, calcifying plankton, crabs, marine snails, (corals?)

Module 3: Community Science and Local Impacts

Lesson 3A: Cascading Impacts

Students review ecosystem connections and discuss how these relationships may be altered by ocean acidification. Students begin to think about how the many ways ocean acidification can effect humans.

NGSS Standards:

  • MS-LS2-1: Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem.
    • Emphasis is on cause and effect relationships between resources and growth of individual organisms and the numbers of organisms in ecosystems during periods of abundant and scarce resources
  • MS-LS2-3: Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
    • Emphasis is on describing the conservation of matter and flow of energy into and out of various ecosystems, and on defining the boundaries of the system
  • MS-LS2-4: Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
    • Emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems.
Lesson Objectives:
  • Students understand that decreased populations of shelled organisms impact other species in the ecosystem.
  • Students connect these ecosystem changes to negative impacts on people and industries in Washington.
Teacher Resources: 
Materials:
  • Pens/pencils
Lesson 3A Overview:
  1. Introduce the lesson topic using Lesson 3A slides. Review the impact of ocean acidification on shelled organisms.
    • Revisit shells from Lesson 2C Activity. Allow students to compare the results to their hypotheses.
  2. Use the Lesson 3A slides to explain what happens to other species when shelled organisms are threatened by ocean acidification.
    • Discuss the effect of ocean acidification on the diets of secondary and tertiary predators.
  3. Activity: Revisiting Food Webs
    • Model before vs. after – food webs with smaller populations of species that depend on calcium carbonate
  4. Discuss how the effects of ocean acidification impact humans.
    • Emphasize the effect on fisheries, tourism, and local livelihoods.

Lesson 3B: Data Collection and ANeMoNe

Students learn ways scientists monitor ocean acidification through programs like Project ANeMoNe.

NGSS Standards:

  • MS-LS2-3: Develop a model to describe cycling of matter and flow of energy among living and nonliving parts of an ecosystem. The living aspect of this standard will be achieved in conjunction with the shelled organism lessons.
  • MS-LS2-4: Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
    • Emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems. This standard will be achieved in conjunction with the shelled organism and data lessons. 
Learning Objectives:
  • Students learn that scientists can and do monitor changes in ocean acidification through research and data collection.
  • Students learn how the ANeMoNe project uses community science to monitor ocean acidification in WA.
  • Students understand the tools and techniques that ANeMoNe uses to collect its data for ecosystem monitoring.
Teacher Resources: 
Materials:
  • Pens/pencils
Lesson 3B Overview:
  1. Use Lesson 3B slides to review the role of a community scientist in Project ANeMoNe.
  2. Activity 1: Data Collection Brainstorm
    • Students  discuss in groups what they would want to collect if they were scientists trying to study impacts of ocean acidification. Remind them that they should focus on both biotic (living) and abiotic (nonliving) factors.
    • Come together as a class and make a list on the whiteboard.
  3. Activity 2: ANeMoNe Data Collection Videos
    1. Introduce data collection by ANeMoNe. The videos show the tools used by ANeMoNe to measure and collect data in the field, as well as what data is being collected. Students are provided with a worksheet to complete with a partner.
      • Between videos, ask students about takeaways or questions they have, to ensure students are understanding each part of the data collection.
  4. Recap the videos and think ahead to the final lesson of the unit, where students work with ANeMoNe data and analyze what the data implies for the nearshore ecosystem.

Lesson 3C: ANeMoNe Data and Local Ecosystems

Lesson Objectives:
  • Students are able to use real data to test hypotheses.
  • Students are able to use data to visualize the effect of eelgrass on the ecosystem at an ANeMoNe site.
  • Students connect the differences between sites to broader ecosystem impacts.

NGSS Standards:

  • MS-LS2-1: Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem.
    • Emphasis is on cause and effect relationships between resources and growth of individual organisms and the numbers of organisms in ecosystems during periods of abundant and scarce resources
  • MS-LS2-4: Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
    • Emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems.
Teacher Resources: 
Materials:
  • Pens/pencils
  • Computers (to access and manipulate the ANeMoNe data)
Lesson Overview:
  1. Use Lesson 3C Slides to review the impact of ocean acidification on organisms and ecosystems.
  2. Activity: Graphing pH data from Fidalgo Bay
    • Students access the “ANeMoNe Data” file on their devices and follow the steps on the worksheet to create a graph of the pH in areas with and without eelgrass using real data.
    • Students graph pH in bare and eelgrass-covered areas, and identify differences between the two graphs.
    • Students should interpret the chart and its elements, and use this knowledge to think about how organisms in these areas may be affected differently.
      • Review basics of x-y plots,  including axes, trendlines, etc.
  3. Discuss the findings as a class:
    • What does this graph tell you about pH levels in Fidalgo Bay?
    • How do you think organisms in each of these areas might be impacted differently?
    • Do you think the differences between pH levels in Bare areas and the Eelgrass areas are enough to impact the other organisms living there?

Attribution: Arnold, A., Byrnes, K., Matteri, E. “Uncovering How Eelgrass Protects Washington from Ocean Acidification” Climate Science for the Classroom edited by Bertram and Olson, 2021. https://uw.pressbooks.pub/climate/chapter/eelgrass-ocean-acidification-and-washington/ Date of Access.

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Uncovering How Eelgrass Protects Washington Waters from Ocean Acidification by Amanda Arnold; Katharine Byrnes; and Elizabeth Matteri is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

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