Why are oysters dying, and how can we use chemistry to protect them?

Why are oysters dying, and how can we use chemistry to protect them? This unit is designed to build a deeper understanding about chemical reactions by exploring reversible reactions through exploration of ocean acidification. Students watch case videos, analyze data, and read about how movement of carbon dioxide from the atmosphere to the ocean makes the ocean more acidic. They consider how oyster die-offs may affect communities that rely on oysters for a food source. Students break down this large scale problem into a few key subproblems so they can use chemistry to try to solve them. They figure out how changes in concentration of H+ ions in water leads to changes in water pH. They use their knowledge of chemical reactions and mathematical thinking (stoichiometry) to determine the amounts of a substance they could use to neutralize acidic water. Students consider engineering trade-offs, criteria, and constraints to use chemistry to develop a design solution at a specific site to address oyster die-offs. They apply their thinking in a culminating task around increasing rates of ammonia fertilizer.