How is CO2 Changing the Seawater? Junior High School Lessons on Ocean Acidification

Abstract

Ocean acidification (OA), driven by increased atmospheric CO2, poses a significant threat to marine ecosystems, particularly affecting organisms that rely on calcium carbonate (CaCO3) for their shells and skeletons. Despite extensive research on OA, there is a notable gap in junior high school science education regarding this phenomenon. This study aims to address this gap by developing and implementing educational materials to enhance Japanese junior high school students' understanding of OA. Two lessons were designed and taught to third-year junior high school students in Okayama Prefecture, Japan. The first lesson investigated the relationship between OA and water temperature through hands-on experiments using artificial seawater and pH indicators. The second lesson focused on the impact of OA on marine organisms, utilizing molecular models to simulate the formation of CaCO3 under current and acidified ocean conditions. Pre- and post-lesson questionnaires assessed changes in students' understanding. The educational intervention significantly improved students' comprehension of OA, with statistically significant increases (p < 0.01) in median scores for eight out of nine questionnaire items. The greatest improvements were observed in students' (N=145) understanding of OA's impact on marine life, highlighting the effectiveness of the lessons in raising awareness of ecological consequences. The study successfully demonstrated that engaging junior high school students with hands-on experiments and real-world data can enhance their understanding of complex scientific concepts like OA. However, further refinement of the lessons is needed to address lack of knowledge, particularly regarding the role of marine algae in OA.