This unit will be taught over 2 weeks, a maximum of 5 blocks (90 minutes long). Students learn Ecology during the third marking period. This unit will be used as an enrichment activity. A couple of challenges about teaching this unit are: sticking to the duration dedicated for this unit while keeping up with the pacing set forth by the district. Upon successful completion, the author could make the necessary changes to the unit and reteach it to other classes.
Classroom Activities:
1. Carbon Cycle (1 block / 90 minutes)
Students will answer the following “do now” question: What do you know about the earth’s carbon reservoirs? The five major carbon reservoirs are rock, atmosphere, oceans, terrestrial biosphere, and fossil fuels.
Learning objectives: Students Will Be Able To (SWBAT) understand that the carbon cycle is fundamental to making sense of environmental changes such as global warming and ocean acidification.
Materials and teacher-developed resources: Five pounds rice (or other small grain or material), cups or other containers for counting and weighing rice, scale, permanent marker, four gallon-sized plastic zip-top bags, five-quart or sandwich-sized plastic bags, a box with the dimensions 10 cm x 10 cm x 10 cm (this can be made from a 1/2 gallon paperboard milk carton, cut in half). meter stick, Carbon reservoir images.
Learning activities: For the first 10 minutes of class, the students will answer the “do now” questions. Then they will conduct the hands-on lab, Follow and Carbon for 40 minutes. During the lab, students will use the chart provided and identify the principal carbon reservoirs and determine the approximate amount of carbon storage in gigatons, where each grain of rice represents a gigatons of carbon. Students will work in 5 groups and focus on one carbon reservoir each ( rock, atmosphere, oceans, terrestrial biosphere, and fossil fuels). They will then model the flow of carbon between the atmosphere and terrestrial biosphere, ocean, and the atmosphere, flow from fossil fuels (the burning of which releases carbon dioxide into the atmosphere) while using the Average Annual Carbon Fluxes chart. This activity will provide students with an understanding of the carbon cycle.
Homework: Students will review the carbon cycle by creating Story Boards with the main focus of tracing the movement of carbon between the atmosphere, land, and the oceans and other bodies of water. They will also take an online carbon cycle Edpuzzle quiz.
2. Ocean Acidification in a cup (1 Block)
Students will answer the following “do now” question: What is Ocean acidification?
Learning objectives: Students Will Be Able To (SWBAT) understand observe a demonstration and understand the concept of ocean acidification.
Materials and teacher-developed resources: Safety goggles, An acid-base indicator such as bromothymol blue, two clear plastic cups (10-oz), paper cups(3-oz), masking tape, plain white paper, permanent marker, baking soda, white vinegar, two Petri dishes to use as lids for the plastic cups, graduated cylinder, gram scale or measuring spoons.
Learning activities: This activity illustrates “how the diffusion of a gas into a liquid can cause ocean acidification. It also models part of the short-term carbon cycle—specifically the interaction between our atmosphere and the ocean’s surface”. When we create a carbon dioxide-rich atmosphere in a cup by adding baking soda (Sodium Bicarbonate) to water and then add vinegar (an acid) and observe the changes. During this reaction one can observe that when bicarbonate is added to water and then the acetic acid in vinegar converts the bicarbonate to carbon dioxide. Therefore, this model shows how carbon dioxide gas diffuses into the water, resulting in the formation of carbonic acid and in the process makes the water more acidic.
(aq) + H2O → H2CO3. Then the carbonic acid dissociates into hydrogen ions and bicarbonate ions. The increase in the hydrogen ions makes the water acidic. Students will observe the modeling demonstration and make qualitative and quantitative observations. They will write down the time it took for the acid-base indicator to change color on the worksheet provided. During the last 30 minutes of the class, they will have an open discussion about the information they collected, the cause and effects of ocean acidification, they will determine if the effects could be reversed, and how.
Homework: Students will complete the ocean acidification in a cup lab report.
3. Shells in Acid- Modeling Coral Bleaching and see why ocean acidification may be giving some marine organisms shell shock.
Students will work on the following “do now” question: What is Coral Bleaching? How does can it be prevented and reversed?
Learning objectives: SWBAT explores how the pH of a solution dictates whether carbon is present in the form needed to make seashells. A wide variety of ocean organisms—from shellfish and corals to certain kinds of algae—contain calcium carbonate in their exoskeletons. There needs to be a sufficient concentration of carbonate ions available for these creatures to construct their shells. The uptake of CO2 in the ocean decreases the concentration of carbonate ions and pH in the oceans, a phenomenon called ocean acidification. This phenomenon is affecting shell formation and coral bleaching.
Materials and teacher-developed resources: assorted seashells, vinegar, calcium chloride (CaCl2, sold as Damp Rid in stores), sodium bicarbonate (NaHCO3, also known as baking soda), 0.25 molar sodium hydroxide (NaOH, sold as lye in stores), several clear cups, water, permanent marker, safety goggles, pH indicators such as cabbage juice, bromothymol blue, or phenol red.
Learning activities: Students will observe a demonstration of the effect of ocean acidification on shell-forming organisms. They will be able to make observations and note down the changes in the cups when shells (primary components are calcium carbonate) are added to cups containing sodium bicarbonate solution ( baking soda and water), calcium chloride solution, and vinegar.
Homework: Students will reflect on the lab and understand the negative effects of ocean acidification on shells and think about creative ways to mitigate this process. If I were a scientist, I would do the following to address/stop and reverse ocean acidification and coral bleaching. They will present their ideas to their peers during the next class.
4. Culminating Activity: Invention Convention Expo
Learning objectives: SWBAT will first have a chance to present their ideas to address ocean acidification to their peers. They will then work in groups of 4 and create awareness posters about ocean acidification and coral bleaching, including how they would address, decrease, stop, and reverse the processes.
Materials and teacher-developed resources: Posters, paper, pencils, markers, computer access.
Learning activities: Students will create awareness posters. They will also draft a letter to their local county/city representatives to grab their attention and create awareness about ocean acidification and coral bleaching. Given that the students are from New Haven and its surrounding towns this topic will help bring their attention to the importance of taking care of the Long Island Sound.
