Harmful Algal Blooms

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Originally appears in the Winter 2021 issue.

By Victoria Ford

Harmful algal blooms (HABs) are on the rise worldwide. In August of 2014, 500,000 Toledo, Ohio residents were told not to drink, cook with, or bathe in their tap water, as it was deemed too toxic due to an extensive algal bloom in Lake Erie[1]. Between 2017 and 2019, 589 sea turtles died as a result of toxic saltwater algal blooms, commonly referred to as red tides in the Gulf of Mexico[2]. Climate change and nutrient pollution are widely believed to be significant factors contributing to these growing threats to our waters[3]. As educators, we need to prepare young people to address current and future environmental issues. One way to do this is to use Project Based Learning (PBL), which incorporates teamwork, critical thinking, problem solving, and time management skills[4]. When engaged in PBL, students are intrinsically motivated because they are directing the project. They are in charge of their own learning and that’s empowering.

Embarking on PBL in a classroom of middle schoolers is no easy feat. It takes accepting some key factors. Gone are acceptable bell curves of student knowledge and easily digestible question-and-answer worksheets. In their place are excited students with often wild ideas — some feasible, some unrealistic. The challenge for the teacher is to reign in students and keep them on track. With 6th-graders, it’s a little like herding kittens — they’re all going off in different directions at once. Harmful algal blooms is a great topic for dipping your toes into the PBL waters. The causes and effects of HABs are readily available on US government websites, including the National Oceanic and Atmospheric Administration (NOAA), The National Aeronautics and Space Administration (NASA), and The United States Geological Survey (USGS). With a little prerequisite knowledge on water quality, testing (especially phosphorus and nitrogen testing), and filtration, students can readily brainstorm solutions.

A harmful algal bloom PBL session can range from a highly guided experience to a student-led endeavor. Background information and resources can be provided to the students for a more guided and controlled experience. From there, students develop their own solutions to the problems. Alternatively, teachers can take a more open approach in which students lead their own research and form their own solutions. Both approaches are valuable and foster critical thinking and problem solving. The best path to take is determined by the teacher as they understand their students. I chose the student-led option and have no regrets, but I do have some advice.

To help with management in the classroom, here are the major sections of an example student-led/open approach to a HABs PBL unit. The unit runs four–six weeks and culminates in a one-hour gallery walk, in which audience members are free to move around a venue where students are presenting their site-specific HABs solutions at individual tables. This PBL unit is broken into three primary phases:

• Phase 1 focuses on researching general causes and effects of harmful algal blooms.
• Phase 2 focuses on a site-specific HAB, then brainstorming and designing solutions.
• Phase 3 is a public presentation of the final product.

Phase 1: Unit introduction and research

You can begin the unit by challenging the students to use their science and engineering skills to help solve the problem of “harmful algal blooms.” After introducing the challenge, students will likely look at you for what to do next, while asking “what’s a harmful algal bloom?” I typically respond with, “figure it out.” They’ll continue to look at you, unsure of what to do; they may even ask what to do again. At this point, I like to say, “Can I introduce you to this thing called the internet?” This usually points students towards what to do first. Since students in my classroom are all equipped with WIFI-connected iPads, they are able to start researching immediately. I keep the introduction intentionally vague so that students must figure out the problems, causes, and effects of HABs through their research. This allows students to take ownership of how they are going to handle the assignment. As is the case with real scientists, the challenge is now in their hands to locate a specific problem and then figure out a solution that they see as fit.

While searching the internet, students will discover bits and pieces of the causes and effects of harmful algal blooms. With intermittent share-outs and a focus on the fundamentals of researching — who, what, why, when, where, and how — the whole class will develop an understanding of the problem. By throwing the challenge at the students cold, it forces them to take ownership of the project. It’s useful, however, to provide a Google Doc two-column note sheet or other shared template (Google Sheets or Slides) as a place for teams to compile information they come across. Taking this open approach allows students to develop research and media literacy skills. However, there are two common issues to look out for: students will sometimes come across information that is too technical for them to understand; the other is verifying that unknown websites are legitimate. This second issue is particularly important given the amount of misinformation that can be found on the web. Both issues can be solved by directing or limiting students to searching such governmental websites as NOAA, NASA, or USGS and discussing the information with students individually.

Students frequently ask if looking things up on the internet is cheating; the answer here is “no.” Every adult, when faced with a challenge, turns to the internet, so why shouldn’t students? What educators need to do is teach students to take the information they find on the internet, verify if it is legitimate by comparing it with other sources, and apply it to the problem they are resolving.

Phase 2: Design thinking and site-specific solutions

Phase 2 of this HABs PBL challenges students to develop a solution or part of a solution to a specific HABs location based on their research. Because environmental problems are often complex, addressing the issues frequently requires a multi-pronged approach. There is rarely, if ever, one single solution to a problem. Therefore, it’s important to stress that tackling just part of a solution is valid and this is why I take this approach with my students on HABs PBL sessions.

When students are first locating a specific HAB, they often find it through a random Google search that piques their curiosity or they target a lake or region that has been mentioned in class. Sometimes two or more students will focus on the same lake, which is fine because their solutions are always unique and frequently different. Creative out-of-the-box thinking frequently occurs during this phase. The solutions students come up with vary. Some examples include massive infrastructure undertakings — laying pipes across the Chesapeake Bay to pump oxygen into dead zones, developing manure for creating biofuel systems, designing nutrient-filtering constructed wetlands, and raising public awareness through letter writing or social media campaigns. In formulating their solutions, students may not be able to know, design, and build every aspect of their solution, but that is okay because the learning is in the thinking, adapting, and realistic application of ideas to a specific problem.

Searching local newspapers and news outlets, local government webpages, and community group webpages is useful for finding and understanding site-specific HABs. These resources usually articulate the problems, causes, and effects in a user-friendly manner. I find that students usually need a little help with this part of the process. I often suggest more specific search phrases like “Harmful Algal Blooms in Hartford County Connecticut,” “Harmful Algal Blooms in Southern Florida,” or “Harmful Algal Blooms and Poultry Farms.” It is also important to direct students to the “news” tab in the results section of Google. Through very specific searches and localized results, students will get much more specific information that will inform their thinking and tailored solutions.

Phase 3: Public presentation
The final phase of the unit, which serves as a summative assessment, involves presenting solutions to adults in the community (teachers, parents, and administrators) and older students. Presenting either individually or gallery-walk-style helps to legitimize the project and make it feel worthy in the eyes of middle school students. 3D representative models, design sketches, maps, and slide shows are useful tools that help students convey the essence of the problem and their solution. To prepare for their presentation, I give students a checklist that serves as a rubric for what must be included in their presentation. Student work should be fabricated from recycled materials in order to teach them about environmentally sustainable project production. Great representative models can be fashioned out of old cardboard boxes, recycled plastic cups, cans, and many other materials found at home or around the science room. Emphasize that the purpose of the work is to help convey ideas, not necessarily show a working model. Also, student presentations should include a section that addresses the limitations and challenges to their solution. This requirement forces students to think holistically and deeper about their specific HAB problem and the workings of their solution. One thing to be aware of is that some students will claim their age as a challenge because “who is going to listen to kids?” With a few guiding questions like, What problems are you not solving? Is your solution addressing the causes of your algal bloom? or Is it addressing the effects? students develop an understanding of realistic limitations.

Taking an open PBL approach to teaching about nutrient pollution, harmful algal blooms, and dead zones is challenging, especially the first time. Be prepared to step aside as a traditional teacher and become a guiding partner. It will be messy and unclear at times. Students will find information and blow it out of proportion. They’ll see what looks like a chicken farm on Google Earth and blame the entire algal bloom in Lake Erie on that one farm. Consequently, you’ll be forced to clarify misconceptions, think on your feet, adapt and change, scrap ideas, and try different approaches. There will be numerous questions, some you’ll be tempted to answer while others you won’t know how to. In both cases, it’s best to push the questions back at the students. Ask them to think more, dig deeper, look further. They are willing and capable, so give them the chance.

Extensions & resources

Spirulina algae can be used for a variety of experiments comparing algae growth based on temperature, light, and nutrient differences. Spirulina can be purchased through Algae Research Supply https://algaeresearchsupply.com/.
Capped and uncapped jars filled with various levels of decaying organic matter, leaves, food scraps, or algae can be used in conjunction with dissolved oxygen probes to study how decomposing matter impacts oxygen levels. Experiments can then be connected to algal bloom dead zones. Probes are available on the internet. One popular source is Vernier: https://www.vernier.com/product/dissolved-oxygen-probe/
Incorporating temperature trends into a HABs PBL project is a great way to connect the increasing rate of algal blooms to climate change. NOAA has a user-friendly web page with temperature information by state and year: https://www.ncdc.noaa.gov/cag/statewide/time-series/5/tavg/1/7/1910-2019?base_prd=true&begbaseyear=1901&endbaseyear=2000
Having students collect location data is a great way to make the project even more meaningful for teachers whose classrooms are near bodies of water. Here’s a test kit that can help students understand the role of nitrates and phosphates in nutrient pollution of water bodies:
https://www.westlab.com/earth-sciences/environmental/water-testing-kits/117-2852-nitrates-phosphates-eutrophication-kit
Frontline Poisoned Waters 2009 — the first half of the PBS Frontline film offers a comprehensive multifaceted view of nutrient pollution, algal blooms, and dead zones. This film can be used to solidify student understanding of the causes and many effects of harmful algal blooms: https://www.pbs.org/wgbh/frontline/film/poisonedwaters/
Google searches for NASA, NOAA, USGS, or EPA combined with the term “harmful algal bloom” will yield many results and plenty of information for students to digest.
For more information about Project Based Learning check out the Buck Institute for Education: https://www.pblworks.org/?_ga=2.19337656.1690183852.1583685257-350620876.1583685257
For those readers who have first-hand or digital access to research libraries, here’s an interesting academic paper that looks at human behaviors impacting nutrient pollution of the Mississippi River and HABs in the Gulf of Mexico:
Justic, D., Rabalais, N., & Turner, R. (n.d.). Modeling the impacts of decadal changes in riverine nutrient fluxes on coastal eutrophication near the Mississippi River Delta. ECOLOGICAL MODELLING, 152(1), 33–46.

Victoria Ford is a 5th- and 6th-grade science teacher at Friends Seminary, an independent Quaker school in New York City, USA. She’s passionate about sustainability, conservation, climate change, and other issues pertaining to the environment. Victoria is currently working on a second master’s degree in conservation biology through Miami University and Project Dragonfly. Her first master’s was in teaching science to middle school students. This is Victoria’s ninth year of teaching middle school science in NYC. For questions, more detailed guidance, or unit materials, please feel free to contact Victoria Ford at vford@friendsseminary.org.

Endnotes:

[1]Lee, J. J. (2016, May 24). Driven by Climate Change, Algae Blooms Behind Ohio Water Scare Are New Normal. Retrieved March 25, 2020, from https://www.nationalgeographic.com/news/2014/8/140804-harmful-algal-bloom-lake-erie-climate-change-science/

[2]Meszaros, J. (2019, January 21). Most Sea Turtle Deaths For Single Red Tide Event. Retrieved March 25, 2020, from https://www.wlrn.org/post/most-sea-turtle-deaths-single-red-tide-event

[3]Schlossberg, T. (2017, July 27). Fertilizers, a Boon to Agriculture, Pose Growing Threat to U.S. Waterways. Retrieved March 25, 2020, from https://www.nytimes.com/2017/07/27/climate/nitrogen-fertilizers-climate-change-pollution-waterways-global-warming.html

[4]Person. (2007, October 19). Why Is Project-Based Learning Important? Retrieved from https://www.edutopia.org/project-based-learning-guide-importance