Ocean Acidification: Is there a problem?

1. Ocean Acidification: Is there a problem? Stacey Sebert

2. Summary Ocean Acidification is a current topic in the ocean and climate news. Students will utilize a guided WebQuest to research the possible future effects of ocean acidification, explore current models used to predict the changes in the ocean’s pH and discuss the current data collection for research. Key Concepts Investigate the development of scientific understanding of ocean acidification.Explore current models for predicting pH changes in the ocean and the instruments used to construct them.

3. Objectives Students will be able to:Navigate the internet to explore ocean acidification findings in the past and predicted future.Record their findings from internet sites on ocean acidification.Demonstrate critical analysis of current (and projected) instruments to measure ocean acidification.Communicate the ongoing story of ocean acidification with classmates in pairs and through whole class discussions.

4. Materials Access to the internet“pH data for the World’s Oceans” mapOcean Acidification WebQuestPowerPoint introStudent Reflection Sheet (including instructor version)Universal Indicator (available through Flinn Scientific U0011 HYPERLINK "http://www.flinnsci.com/store/Scripts/ck_prodList.asp?Index=9873" http://www.flinnsci.com/store/Scripts/ck_prodList.asp?Index=9873)pH paper or pH probes can be used as wellDrinking strawsPlastic bags or cupsShell fragmentsPlastic bag or cup with vinegar

5. Procedure Day 1 Pass out student reflection sheet. Use PowerPoint, SmartBoard, blackboard, overhead or any method that fits your situation, and introduce the first question What do you know about ocean acidification?Pass out WebQuest Part I (best method is to have an electronic copy for students or have already loaded the URL’s on the classroom computers to avoid errors). It might be helpful to have the entire class watch the MBARI YouTube video (avoids echoing effect). Monitor student completion of the WebQuest. Use teacher discretion as to how you will assign the 13 sections. For example, you might assign sections to different groups of students and then have them present their “findings” to class. You can also have students work in pairs and then stop every 10-15 minutes to have the entire class regroup and share their findings. Assign Part II as homework.

6. Day 1 Reflection Sheet Review Most of my students answered the first question by saying they didn’t know anything about ocean acidification. I didn’t use the student version of the reflection sheet as it didn’t have anything on it and my students couldn’t remember what questions I was asking, when. So I used the instructor version for the students so that they could reflect when they got to certain points in the activities. I conducted this lesson with 8th grade students and many of them work at different rates so I thought it would be better to let the students have the questions ahead of time and have the time needed to reflect upon them.

7. Day 1 Webquest Review I spent a lot of time preparing the Webquest ahead of class. A few of the links were broken and I had to search to find the correct (or updated) link. One link I had to create a new link of an article which I thought was very similar. I looked over the links since some were higher level terminology, I matched the student with the article based on reading ability. I made a google doc’s page for the students to make it easier for them - instead of typing the entire link out, they just clicked on the link I assigned them. I felt my students needed more than one class period for this as they didn’t have enough time for research and presenting their research to the class, while writing down what others researched. I assigned groups of 2 for the harder sections and 1 student for the easier selections.

8. Day 1 Homework Part II Review The homework was to write down the weather forecast and then see the next day how accurate the prediction was. I can see how this is supposed to show how scientists are predicting the acidification of the ocean but many of my students felt that this didn’t really connect well. I also felt that it could have had more information for students to gather. II made it more specific with temperature highs and lows, humidity, cloud cover, chance of precipitation, etc. Also, our weather forecasting can be very inaccurate, especially when it comes to snow storms and conducting the activity in January lead to more inaccurate forecasts. I’m not sure I would use this piece of the unit again. This activity would tie in better with my weather unit, which I started right after this activity. I also would have assigned students different channels or websites to see if it varies with the source as well.

9. Procedure Day 2 Discuss Part II findings and assign Part III and IV (make sure to pass out the pH data for the World’s Oceans map).Have students work in pairs on Part III and IV or work through it as a class (if you choose the latter option, it might be a good idea to have the students plot the pH data for the World’s Oceans map points as homework on Day 1).Make sure to bring closure to the discussions on Parts I, II, III, and IV.

10. Day 2 Review My students discussed the forecasting and how accurate the forecast was and how it changed and became more accurate as time when on. My students were confused with the world map pH sensors as many of the data points seemed to be on US land and not in the ocean. These activities didn’t take too long so we were able to finish up the webquest stuff from the day before as well as having closure of the activities we’ve completed thus far.

11. Day 3 Procedure Have students (or student pairs), grab a Ziploc bag with tap water (distilled or even saltwater could be used instead) with universal indicator already inside (around 200ml of water and enough Universal Indicator to make a color change) and a straw. Display procedure in front of class (also display color chart). pH paper and probes may also be used, but they don’t have the same visual effect as the indicator.Have students blow through straw into water/universal indicator solution until there is a color change. Ask what makes the color change? SAFETY PRECAUTION: make sure to instruct students to remove their mouth from the straw during inhale (to avoid ingesting the water/indicator mix).Hand student groups a baggie or beaker with vinegar. Have them record the pH of the vinegar.Drop a shell fragment into both the baggie or beaker with vinegar and the baggie or

12. Day 3 Procedure continued beaker that they just blew in. Have them discuss and/or record what is happening in both baggies/beakers. Display the fake facebook page (found on student reflection PPT). Discuss what the entry is prompting.After students clean up, have them complete the last three squares of the student reflection sheet, using the back if needed. (Questions are on the instructor version.)

13. Day 3 Review I found that for the lab, the baggies tended to leak the water and vinegar a lot. Next time, I would use beakers for this part of the activity. This lab was everyone’s favorite part of the unit. Students really liked the activity and could see visually what would happen to shells if the oceans became more acidic. The universal indicator made a nice visual effect for students. They liked the green, yellow, and red colors (like a stoplight). I had a picture of the colors lined up with the number pH on the overhead. I added a control - tap water without carbon dioxide in it so that students could have a basis to compare their other shells to. We kept the shells in the liquids overnight. It wasn’t enough time to see a difference during the class period.

14. Day 3 Review continued I created a lab page for this activity as my students wouldn’t be able to follow the powerpoint. I added some questions and had the students predict what they thought would happen to the shells in each of the containers. My students didn’t really get the fake facebook page. I think using something else may be a better idea. The article about the pH of the ocean really hit home. The students saw how quickly the acidity of the ocean is changing and not for the better. I had this activity go into a 4th day as the shells didn’t really change during class. My students finished up the lab questions on the 4th day instead.

15. Lab Write Up Page 1 Ocean Acidification LabQuestion: What do you think will happen to sea shells in acid?Hypothesis (If, then, because):Materials:Ziploc bag with water (200 ml) and sea shell as a control groupZiploc bag with water (200 ml) and universal indicatorStrawpH paper and color chartShell fragmentsZiploc bag with vinegar (200 ml)

16. Lab Write Up Page 2 Experiment: • Grab a Ziploc bag with water, a color chart, and a straw. • Using the straw, blow into the water in the bag until there is a color change. The universal indicator changes color when there is a change in pH.SAFETY PRECAUTION: make sure you don’t inhale the water and indicator mix! • Grab a bag with vinegar. Record the pH of the vinegar here: _________________. • Drop a shell fragment into both the bag with vinegar and the bag with water you blew into. Record what is happening in both bags below. Compare this to a shell in water that wasn’t blown into.Mass of shell pieces:Before:After:Bag with vinegar:Before:After:Bag with water and CO2:Before:After:Bag with water (control):Before:After:

17. Lab Write Up Page 3 Please answer the following questions in complete sentences. • What exactly did you blow into the bag with water to make it change pH? • Check out the Facebook page on the projector. What is the entry indicating? • How is the acidity of the ocean changing? • How did the mass of shells change from before to after the experiment? Why do you this happened? • What do you think will happen to the living creatures (plants and animals) if the acidity level of the ocean keeps changing? • What are some ideas you can think of to stop this change? Name at least 2. • Complete the last 3 squares on the student evaluation sheet from Day 1, you can use this sheet if you need more space. Turn the evaluation sheet in along with this lab sheet.

21. Day 4 Review Students could clearly see a difference in the shells between the 3 different liquids. I also put a shell in hydrochloric acid for students to really see what happened to a shell in strong acid. While some parts of the activity seemed to confuse my students, they understood what the overall take away idea was - that the oceans are becoming more acidic due to human activity and that we should try to do anything we can (reduce, reuse, recycle, use more renewable energy, etc.) to try to slow this process down. Most of my students said I should do this activity again (with a few changes) with my 8th graders next year as they enjoyed it and understood the overall message the activities were trying to convey.

22. Questions my students had after... D – What would you still like to know? What other questions do you have? • How long does it take to break down everything in the ocean? • How long will it take before everything is gone? • How can we stop using factories if we need them? • How can we stop ocean acidification? • Can it affect all shells or just clam shells (which is what we used)? • Can we stop ocean acidification completely or at least partially? • What specific animals and plants are dying in the ocean and how can we help them? • Are there ways we can stop all the CO2 from getting into the ocean? • Why do people still use energy that pollutes? Do they want to harm coral and animals in the ocean? • Can we fully stop this from happening? • How can we prevent this from happening? • Why can’t we find an efficient way to change this from happening? • Why don’t humans do anything to change this? • How many plants and animals are killed by ocean acidification currently? • How can we stop this? Can we even stop this?