Impact of Ocean Acidification on Shelled Organisms: Supporting Integration of Chemistry and Biology Knowledge through Multidisciplinary Activities

Students often experience difficulty in connecting knowledge fromdifferent college courses to solve complex problems such as ocean acidification, apressing concern within the ongoing climate crisis. Here, we introduce a multi-disciplinary activity in which students use their chemistry knowledge of change andstability in chemical systems through Le Chatelier's principle and equilibrium of coupledreactions to explain the biological phenomenon of how changes in CO2concentrationscan impact shelled organisms and ecosystems more broadly in the ocean. In this activity,we build on prior literature and emphasize Three-Dimensional Learning (3DL) tosupport students in developing a deeper understanding of this complex problem. ThisOcean Acidification activity asks students to explain (1) the relationship between CO2concentration and ocean pH and (2) how and why changes in ocean pH could weakenshelled organisms. Among 136 students in a second-semester general chemistry courseat a large institution, 93% were able to correctly predict the relationship between CO2and pH (chemistry-biology connection). Additionally, 43% of the students were able tothen further apply this knowledge correctly to explain an unfamiliar situation in which the decreased pH could lead to less availablecarbonate ion for the shells (biological phenomenon). This result highlights that while some students were able to correctly explainthe biological phenomenon and make meaningful connections, others would require additional in-class scaffolding and student-instructor interaction to be able to integrate their knowledge to explain this unfamiliar complex biological phenomenon. Implicationsfor teaching and future implementations are also discussed