Carbon dioxide contributes to greenhouse gases that trap the Sun’s reradiated heat, causing global warming, which also means ocean water is warming. While other human activities are affecting seawater’s acid-base balance and may be important locally, their total effect is small in comparison with the changes driven by rising atmospheric carbon dioxide (WHOI 2018). The investigation should answer the question: “When water increases in acidity, how does it impact underwater plants and/or seashells (depending on which materials you are using)?” Once students have written their hypotheses, materials, and procedure into their science notebooks, lead a whole-class discussion emphasizing the need to hold all variables constant, except the one being tested (water acidity). Evaluate Ask students to draw a model that shows a causeand-effect chain: the burning of fossil fuels (in power plants, transportation, and factories) to less seafood in the supermarket.
Christie-Blick, K., 2019. Ocean acidification investigation. Science Scope 42 (5): 42-50. Article (subscription required).
