Harmful Algal Blooms

Harmful Algal Blooms

Robin McLachlan, Isaiah Bolden, Angie Boysen, and Christine Baker

Overview

Curriculum includes 4 lessons, each with powerpoint presentations, worksheets, videos, readings, and hands-on lab activities which can take up to 3 weeks to complete.  Some parts can be excluded, for a one-week exploration of HAB’s.

Harmful algal blooms (HAB’s) on Washington state’s coast and around the world provide a marine context for a grounding phenomenon to teach ideas from biology and chemistry. Students build a conceptual model of harmful algal bloom occurrence and evaluate the socio-economic impacts of climate change on blooms.  These lessons were developed by Robin McLachlan, (mclachlan.rl@gmail.com), Angie Boysen, Isaiah Bolden, and Christine Baker, all graduate students at the University of Washington, with advising from Professor Mark Windschitl (UW College of Education) and in partnership with the teachers and students of Jane Addams Middle School. Partial support for this work came from the IGERT Program on Ocean Change and the Program on Climate Change. This project fulfilled the capstone requirement for Robin McLachlan’s Graduate Certificate in Climate Science.  

Read about the team and curriculum development in Robin McLachlan’s November 2018 blog post “Teaching Climate Science Using A Local Phenomenon: Harmful Algal Blooms”.

Grade Level: 6th-8th Grade

Meets Next Generation Science Standards MS-LS1-6, MS-LS2-1, MS-LS2-2, MS-LS2-3, and MS-LS2-4.

Lesson 1. Introduction to Phenomenon: Harmful Algal Blooms (HABs)

Students create a conceptual diagram and then grow an algal bloom in the classroom.

Lesson 2. Ecosystem Trophic Interactions

Students play a game (Trace the Toxin) to explore trophic level interactions and trace the flow of energy throughout the marine environment.

Lesson 3. HABs Case Studies and Links to Climate Change

Students analyze real case studies to learn the environmental factors that cause algal blooms and evaluate the impact of climate change.

Lesson 4. Plankton Identification, Scientific Drawing, and Conceptual Model Revision

Students use microscopes to look at plankton and practice scientific drawing. Students conclude by revisiting and revising their conceptual models.

Background Information for Teachers

What are algae? 

Basic definitions of algae can be found here and here.

Harmful Algal Blooms (HABs):

Algal blooms occur when water conditions are ideal for phytoplankton growth. Therefore, blooms tend to occur when water is relatively warm and full of nutrients. Algal blooms become harmful when the phytoplankton produce toxins that cascade through trophic levels. The species Pseudo-nitzschia produces a neurotoxin called domoic acid. The toxin is concentrated as it travels through the food chain from phytoplankton to zooplankton to fish and so on. Human consumption of domoic acid can cause vomiting, diarrhea, cramping, and even death.

The 2015 HAB on the US west coast:

In 2014, a huge patch of ocean water that was anomalously warm (~4.5 °F warmer than normal) persisted off the west coast of the US. It was termed The Blob when its size reached 1,000 miles long, 1,000 miles wide, and 300 feet deep. The persistent warm water triggered a large bloom of Pseudo-nitzschia, a toxin-producing phytoplankton. The toxin was passed up the food chain to razor clams and crabs. In 2015, extremely high levels of domoic acid were detected in common fishery species, such as clams and crabs. In response, recreational razor clam harvests were closed in Washington and Oregon, and recreational and commercial fishing for Dungeness and rock crab were closed on the northern California and Oregon coasts.

Resources:

An unprecedented coastwide toxic algal bloom linked to anomalous ocean conditions: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL070023

Harmful algal blooms and climate change: Learning from the past and present to forecast the future:

https://www.sciencedirect.com/science/article/pii/S1568988315300615

Ocean warming since 1982 has expanded the niche of toxic algal blooms in the North Atlantic and North Pacific oceans: http://www.pnas.org/content/114/19/4975?ijkey=c9a9f3e1d90b1a1f5f6f97b05c515a418a7f798f&keytype2=tf_ipsecsha

Lesson 1:  Introduction to Phenomenon: Harmful Algal Blooms (HABs)

Students create a conceptual diagram and then grow an algal bloom in the classroom.

 NGSS

  • MS-LS2-3 – Ecosystems: Interactions, Energy, and Dynamics.  Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
  • MS-LS2-4 – Ecosystems: Interactions, Energy, and Dynamics. Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.

Materials

  • Pens/pencils
  • Lesson 1 Worksheets (.docx file)
    • Conceptual Diagram (1 per student or group)
    • Bloom Hypothesis Notecard (1 per student or group)
    • Exit Slip (1 per student)
  •  Let’s Grow A Bloom materials:
    • At least 4 glass jars
    • Water sample (containing plankton) from a lake, ocean, and/or fish tank.
      • Request from the Seattle Aquarium at least one week before the lab is to be done.  Send your plankton sample request to: registration@seattleaquarium.org with “plankton request” as the subject line.
      • Or collect your own sample in a jar from a fish tank or lake with a lot of algae (the water will be green or brown). If the water source does not have a high concentration of algae, you can collect a sample with a plankton net. If you don’t have access to a plankton net, you can build your own.
    • Liquid algae fertilizer (e.g. Seachem Flourish)

Introduction

Introduce students to HAB’s using Lesson 1 Presentation.

Activity 1: HAB Conceptual Diagram

  1. Give students five minutes to write down/draw (1) what they know about HABs and (2) any wonderings/questions they still have [e.g.: what algae are, what a bloom is, what do you know about the Pacific Northwest marine ecosystems, what do algae need, how do they fit into the food web].Have them write down their thoughts in the “What do I know?” column.
  2. Break the students into groups. Instruct them to share what they know and what questions they still have. While students share, the others should write down things they learn and new questions that arise.
  3. As a group, the students will create a model on the Conceptual Diagram worksheet provided. This should include drawings and words.
  4. Discuss as a class. Before moving on to the next activity, make sure students agree that algae need warmth, sunlight, and nutrients to bloom.

Activity 2: Let’s grow a bloom!

This activity guides students through building real algae blooms in jars. Each jar receives a different combination of ingredients – light and nutrients. To expand this activity to include temperature as an ingredient, you can add heat lamps and ice baths. This activity can either be done as a class or as a “cooking show” style activity in which the process is discussed and then the premade jars are presented.

  1. Fill at least four glass jars with water that contains algae. Algae are naturally present in lakes, ponds, oceans, fish tanks, etc. Do not cap the jars.
    • Jar 1: place in a dark area such as a closet
    • Jar 2: place in a well-lit area such as a window
    • Jar 3: add liquid fertilizer and place in a dark area
    • Jar 4: add liquid fertilizer and place in a well-lit area
  2.  Give each group or individual a notecard (Bloom Hypothesis Notecard under “Materials”) and assign them a jar. Ask them to write their hypothesis of what will happen to their jar on the notecard.
    • Questions to consider:
      • Will the algae grow to create a bloom?
      • What will the water look like? Why?
      • What will it smell like? Why?
      • How long will it take? Why?
  3. Conclusion: Have students complete exit slips before leaving class.

Lesson 2: Ecosystem Trophic Interactions

(Based in part on the New York State Department of Environmental Conservation Freshwater Fisheries “I FISH NY” Program)

Students will develop new and apply existing knowledge of marine organisms to trace the flow of energy throughout the marine environment.

NGSS

  • MS-LS2-2 – Construct an explanation that predicts patterns of interactions among organisms across multiple ecosystems.
  • MS-LS2-3 – Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.

Materials

  • Life cards (1 per student)
    • This version uses only zooplankton, small fish, seal, and shark cards
    • Class size may vary, but always have ≥ 55% of total organisms as zooplankton for standard rounds of play.
  • Colored tokens
    • > 100 tokens
    • Plastic poker chips work well
    • At least 3 different colors with 1 color ≅ 30% of the total pool
  • Cup/containers (1 per student)
  • Exit Slips (1 per student)

Introduction

Prepare and deliver a brief (5 minutes maximum) presentation on the importance of energy flow and cycling within marine ecosystems, using the Lesson 2 Presentation.

Activity 1: Marine Food Pyramid and Food Web Brainstorming

  1. Ask the students to think about where energy for a variety of marine organisms comes from, gradually working your way toward the sun as the main source and phytoplankton as primary producers in the marine food web. Define terms as necessary. Ask the students to consider which organisms constitute the next stop in energy flow, zooplankton, and that they represent primary consumers.
  2. Ask students to think about where energy flows from the primary consumers. Ask them to volunteer types of organisms beyond phytoplankton and zooplankton that are found in the marine environment. Write these on the board, asking the students to think about connections between each organism (who consumes whom?). Draw arrows that represent the flow of energy and nutrients between these organisms.
  3. After all of the arrows have been drawn, emphasize the intricacies of the web. Shift focus to filling in an energy pyramid. Ask the students to think about the arrows they drew and the fact that organisms that eat other organisms are in distinctly different levels of the pyramid to fill in the trophic spaces (secondary consumers through tertiary consumers) of the pyramid.
    • Primary producers: Phytoplankton
    • Primary consumers: Zooplankton
    • Secondary consumers: Small fish, etc.
    • Tertiary consumers: Large fish, crabs, seals, etc.
    • Quaternary consumers: Sharks, orcas, etc.
  4. Ask the students where they think humans may fit in on the trophic pyramid and the food web. Allude to the possibilities of feedbacks of human activities (overfishing, nutrient loading, etc.) on connections throughout the ecosystem.
  5. Draw attention to the fact that the energy diagram is shaped like a pyramid because there isn’t a lot of energy available for organisms the higher their trophic level. For example, relatively, there aren’t a lot of sharks but there are a lot of phytoplankton. It also signifies that energy accumulates up through trophic levels, a fact that will be best demonstrated by the “Trace the Toxin” game.

Activity 2: Trace the Toxin

  1. Make a clear open space in the classroom by pushing the desks to the sides.
  2. Scatter colored tokens (at least 3 different colors with 1 color ≅ 30% of the total pool) throughout the classroom. These tokens represent phytoplankton. Designate one of these colors as a phytoplankton species that produces harmful toxins, but do not reveal this information to the students yet.
  3. Hand out a Life Card (under materials) to each student. Students should quietly read their life card to themselves as it contains important information for what their role will be during each round of the game. Class size may vary, but always have ≥ 55% of total organisms as zooplankton for standard rounds of play.
    • Organisms on Life Cards: zooplankton, small fish, seal, shark.
    • After each round, keep a tally of remaining organisms in each trophic level on the board. This will be useful for conveying energy pyramid dynamics AND biomagnification.
  4. Round 1 – Ask the students which organism(s) out of the 4 in play would most likely consume phytoplankton (zooplankton, which represent the primary consumer level of the marine energy pyramid and food web).
    • Hand out a food bag/cup to each of the zooplankton. These students will have 10 seconds to “graze” upon the phytoplankton tokens scattered throughout the classroom. In order to graze, students must bend down, pick up one token, stand up, and place it into their cup. All students must walk while doing this for safety reasons. Students are also not allowed to take whole handfuls of tokens at a time. Emphasize that students follow the instructions on their Life Card.
    • At the end of the 10 second period, stop the collection of tokens. Tally remaining organisms on the board.
  5. Round 2 – Ask the students which organism(s) out of the 4 in play is the next level of the food web and pyramid (small fish, which represent secondary consumers).
    • Zooplankton will continue feeding on phytoplankton tokens scattered throughout the classroom, but now, there are predators! If phytoplankton are tagged on the elbow, they must hand their food bag/cup to their predator and exit the game.
    • Small fish will have 10 seconds to “eat” zooplankton (tag them on elbow). Remind the students to follow their Life Card instructions for a reminder on how much they can eat.
    • After the 10 second period, stop the round. Tally remaining organisms on the board.
  6. Round 3 – Ask the students which organism(s) out of the 4 in play is the next level of the food web and pyramid (seals, tertiary consumers).
    • Remaining zooplankton will once again continue feeding on phytoplankton tokens while attempting to avoid small fish.
    • Small fish will continue consuming zooplankton (if their Life Card quota has not been met) while avoiding seals.
    • Seals will have the length of the round to “eat” small fish by tagging them on the elbow.
    • After the 10 second period, stop the round. Tally remaining organisms on the board.
  7. Round 4 – Ask students to verify the only remaining organism (sharks, quaternary consumers).
    • Remaining zooplankton will once again continue feeding on phytoplankton tokens while attempting to avoid small fish.
    • Small fish will continue to consume zooplankton (if their Life Card quota has not been met) while avoiding seals.
    • Seals will continue to consume small fish (if their Life Card quota has not been met) while avoiding sharks.
    • Sharks will have 10 seconds to “eat” seals by tagging them on the elbow.
    • After the 10 second period, stop the round. Tally remaining organisms on the board.
  8. Summarize the game, asking students why rounds became progressively more difficult and what it suggests about predator-prey interactions in the marine environment. What patterns did they see? What caused the patterns? Think about how much energy was needed at higher trophic levels and what the implications are of not being able to meet the quota on a Life Card due to competition. What would be the implications of human populations overfishing the small fish population on the rest of the web AND on nutrient loading sparking phytoplankton blooms? What has this got to do with the 2015 Blob? How else may humans impact the cycling of energy in marine ecosystems?
  9. Reveal the identity of the “harmful” token to the students. Explain that some phytoplankton produce harmful toxins that can be deadly to other organisms. Have the remaining students with food cups/bags count the number of tokens and the total number of harmful tokens within their entire trophic level. Write these values, along with the associated organisms, on the board, and calculate the average amount of toxic chips per trophic level.
  10. Conclusion: Wrap up with a discussion of marine food webs and pyramids and general Q&A. Hand out exit slips.

Lesson 3: HABs Case Studies and Links to Climate Change

Students will learn about recent Harmful Algal Blooms (HABs) around the world, the environmental factors that caused them, and predict the link with and impact of climate change. 

NGSS

  • 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.
  • MS-LS2-3 – Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
  • MS-LS2-4 – Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.

Materials:

  • Pens/pencils
  • Worksheets (.docx file)
    • Entrance slips (1 per student)
    • Jigsaw Worksheets (1 per student)
    • Expert Jigsaw reading material (1 case study per student)
    • Exit Slips (1 per student)

Introduction:

After students have completed their Entrance Slip, present the initial slides on the Lesson 3 presentation until the Jigsaw Activity.

Activity: Jigsaw

  1. Divide students into jigsaw groups (ideally 5 students per group)
  2. Divide the material into 5 case studies
    • Assign each student one case study to become an expert on.
    • Provide a worksheet for students to record information.
    • Case studies: West Coast, Great Lakes, Chesapeake Bay, Florida, Arabian Sea
  3. Allow students to individually read their case study and fill out the worksheet.
  4. Form temporary “expert groups” by having one student from each jigsaw group join the other student assigned to the same case study. Allow expert groups time to discuss the main point of their case study and prepare a short explanation that they can present to their jigsaw group.
  5. Bring students back into their jigsaw groups, ask each student to present their case study to the group, and then fill out the rest of the worksheet with an overview of each topic.
  6. Note: The structure of the reading and note-taking will need to be tailored to the class level.
  7. Conclusion: Use Lesson 3 presentation for classroom discussion and have students complete exit slips before leaving class.

 

Lesson 4: Plankton Identification, Scientific Drawing, and Conceptual Model Revision

Students will use microscopes to look at plankton and practice scientific drawing, and then revisit their conceptual models.

NGSS

  • 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.
  • MS-LS2-3 – Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
  • MS-LS2-4 – Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
  • MS-LS1-6. Construct a scientific explanation based on evidence for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms.

Materials:

Introduction

After students have completed their Entrance Slip, recap as a class the results of the Let’s Grow a Bloom activity. Did we build a bloom successfully? How can we tell? Why did it work? Or why not? Then, introduce HAB species on Plankton ID sheets. Use the Lesson 4 presentation.

Activity 1: Plankton ID

  1. Have students in groups at microscopes look at plankton from local water sources (ponds, rivers, etc.) and the bloom experiment. Can they ID any?
  2. Practice scientific drawing. Think about scales (sizes). Think about how this fits with the activity we did on Wednesday.

Activity 2: Re-visit Phenomena Models

  1. Did anyone see any phytoplankton? Zooplankton? Which caused the problem?
  2. Generate a word bank from the previous activities.
  3. What problems do humans feel from HABs?
  4. Revisit models. (Individually for 3 min sketch ideas, then 12 min in groups)
  5. In groups: have students with ‘roles’ so they stay on task. Someone to make sure we’ve got all the ideas from the word bank. Someone to make sure everyone is participating. Timer. Someone to re-state ideas. Someone to share out at the end (this person will come up to the front where we have the big drawing).
  6. Draw a big model on the board and have each group add to it with a different color.
  7. Conclusion:
    • Hear from each group about how they revised their original model from day one
    • Hear from each group about their connection between Climate Change and People’s’ actions
    • Group discussion – drawing up key ideas on the board for a group model
    • Complete exit slips
Attribution:  Mclachlan, R., Bolden, I., Boysen, A., Baker, C.“Harmful Algal Blooms” Climate Science for the Classroom edited by Bertram and Biyani, 2019. https://uw.pressbooks.pub/climate/chapter/harmful-algal-blooms/ Date of Access.

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Harmful Algal Blooms by Robin McLachlan, Isaiah Bolden, Angie Boysen, and Christine Baker is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

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