Researching Ocean Acidification in General Chemistry
This research-based student project used the problem of ocean acidification to cover the sustainability concept of fossil fuel combustion and the disciplinary concepts of kinetics, equilibrium, acid-base chemistry and solubility. Students are introduced to the concept of ocean acidification through news articles and videos and then deepen their understanding of the issue through in class group learning activities and a seminar style discussion of a journal article. Students then design and carry out a research project that spans anywhere from two lab sessions to an entire quarter. The project culminates in a presentation of their results to both their peers and the wider campus community.
Context for Use
Description and Teaching Materials
The Learning Activities
- Introduction to Ocean Acidification. As an introduction to the project, students read at least one brief news article pertaining to the current status of ocean acidification. A short video clip is viewed in class to spark interest in the topic and provide information about the issue. Some examples of news articles and video clips are listed below in the References and Resources section.
- Content Focused Group Learning Activity. The next step is to learn the core chemical content that will help students to better understand the science behind ocean acidification. Students engage in a combination of lecture and group activities around kinetics, equilibrium, acid-base chemistry, and solubility (depending on how the instructor decides to frame the topic). An activity sheet for implementing a group activity pertaining to acid/base chemistry and ocean acidification is attached.
- Reading the Literature and Participating in a Seminar. In order to deepen student knowledge of current research on the topic, a current journal article is assigned to read and prepare for participation in a classroom-based seminar style discussion. Students are asked to come prepared to the discussion with a summary of the article as well as several key points that they would like to discuss further. The summaries are collected and scored. During the seminar, students are asked to follow a very structured protocol that was developed by Jim Harnish at North Seattle Community College (See the seminar protocol below).
- Engaging in a Research-Based Project. Students are given class time to begin the process of designing an experiment that they could conduct as a part of the course. This research-based activity can be completed in as little as two or three lab periods, or students could be asked to develop a research question that might require months to years to complete. Attached are two examples of how this activity was used at North Seattle Community College in two different general chemistry courses:
Chemical Kinetics and Ocean Acidification:
In a second quarter general chemistry course, the ocean acidification project replaced the regular Decomposition of H2O2 lab, which is the final laboratory session and is focused on concepts in chemical reaction kinetics. Therefore, students were told to think of a question that they had about the rate of ocean acidification. After they formulated their initial questions with their regular lab partners, the groups were then asked to come up with a hypothesis and to design a laboratory experiment that would allow them to test their hypothesis in two lab periods. Students were told that they would present the results of their research to the class. As students formulated questions and hypotheses, and designed experiments, the instructor walked around the room and talked with each group to ensure that each group was asking a different question about the rate of ocean acidification. During the second class session, the students spent the second half of class refining their experiments and each lab group handed in their experimental design (including Required Materials) at the end of class. By the end of the second class session, students had come up with the following research topics:
Group #1: Calcite versus aragonite
Group #2: Effect of salinity
Group #3: Buffering capacity
Group #4: Effect of organic matter
Group #5: Effect of pH
Group #6: Effect of temperature
Group #7: Effect of surface area
Between the second and third class sessions, the instructor met with the chemistry laboratory technician to discuss the students' Required Materials lists. With the help of the laboratory technician and a quick trip to The Aquarium Store to pick up crushed coral, whole coral, and hermit crab shells, the materials were ready for the students by the next laboratory period. It took the students two 2-hour class sessions to set up their experiments. Because kinetics was our content focus, the students took a sample every day for seven days. All groups looked at the mass loss of coral and/or shells with time. Each group needed anywhere from 10 - 40 minutes to remove a sample from their beakers and put it in the drying oven, weigh their dried samples from the previous day, and adjust the pH of their beakers.
After the final sampling day, students were given guidelines for their class presentations. Before they gave their presentations, the instructor spent half of a class session helping them work with and interpret their data. In preparation for this Data Analysis session, each group was told to enter all of their data into an Excel spreadsheet. They were also told to bring, at a minimum, to the Data Analysis session:
(1) A graph of mass loss (in mg) versus time (in hrs) for their control and for each experimental treatment on the same graph.
(2) A table that displays the mass loss (in mg) for individual values, the mean, and the standard deviation of all replicate samples.
During the next class session, each lab group worked with their data on laptops and struggled to make sense of it. By the end of the hour, each group was prepared to present their results to the class. During the final class session dedicated to Ocean Acidification, the students presented their results to each other in 10 minute PowerPoint presentations.
Instructor Notes: The experimental set up could be improved to both reduce the time required to tend to the experiments each day and to improve the results in terms of applying kinetic rate laws to the experimental results. During this activity, students had to adjust the pH of their beakers each day using HCl.
Undergraduate Research on Ocean Acidification as a Capstone Project in the Atoms to Ecosystems Program:
Students in this class were asked to develop a research project to be conducted during the last quarter of a year long program that brings together College Biology and General Chemistry for science majors. The initial phase of the project was completed in 11 weeks, but one of the students involved plans to continue working on the project over the summer and into next year. Students were asked to submit the following items during the quarter:
(1) Research project topic and initial primary literature references
(2) Research project proposal in the form of a 5 minute PPT presentation to the class
(3) Research project progress report
(4) Final Poster
Three students selected ocean acidification as their research topic. They worked on the project all of spring quarter and then presented their results at the Making Learning Visible Symposium at North Seattle Community College. Their poster "Ocean Acidification in the Pacific Northwest", which describes the project, is an Adobe file in the Attachments section.
What's in a Seminar? (Microsoft Word 31kB Nov1 11)
Example of Student Work- Poster Activity (Acrobat (PDF) 822kB Nov1 11)
Acid Bade Activity 1 (Acrobat (PDF) 71kB Nov1 11)
Teaching Notes and Tips
We had the opportunity to take our students to the University of Washington to hear a talk on Ocean Acidification by Dr. Robert Freely from NOAA. This was a wonderful experience for our students and added greatly to their projects.
Student Artifacts: Seminar preparation summaries, experimental design assignment, research proposal, in-class content focused activities, final poster.
Students Perceptions of their Learning:A simple student survey at the end of the project could be conducted including questions such as:
(1) Did the Ocean Acidification lab enhance your understanding of concepts covered in this course? Why or why not?
(2) Did the Ocean Acidification lab enhance your understanding of the scientific process in general? Why or why not?
For longer term research projects the CURE (Classroom Undergraduate Research Experiences) Survey is useful to gain a comprehensive view of the experience for students and can be accessed over the internet.
References and Resources
News Focused Articles
- Kerr, R.A. 2009. The Many Dangers of Greenhouse Acid, Science, VOL 323, 459.
- Doney, S.C. 2006. The Dangers of Ocean Acidification, Scientific American, 58-65.
- The Royal Society. 2005. Ocean Acidification Due to Increasing Atmospheric Carbon Dioxide, Sections 1 & 2 (13 pages)
- Guinotte, J.M. and V.J. Fabry. 2008. Ocean Acidification and its Potential Effects on Marine Ecosystems, Annals of the New York Academy of Sciences, 320 - 342.
- BBC News: Researchers Working with Underwater Volcanoes off the Coast of Naples on Ecosystem-scale Effects of Ocean Acidification. http://news.bbc.co.uk/2/hi/science/nature/7936137.stm
- EUR Ocean Project: http://www.eur-oceans.info/Resources/films.php
Research Articles for Seminar
- Orr, J.C., et al. 2005. Anthropogenic Ocean Acidification Over the Twenty-first Century and its Impact on Calcifying Organisms, Nature, Vol 437, 681-686.
- Doney, S.C., Fabry, V.J., Feely, R.A., Kleypas, J.A. 2009. Ocean Acidification: The Other CO2 Problem, Annu. Rev. Marine. Sci., 1, 169-192.