Engaging Students in the Pacific and Beyond Using an Inquiry-Based Lesson in Ocean Acidification

ABSTRACT

We present a hands-on, inquiry-based activity exploring how CO₂ input to seawater affects the skeletons of several species of reef-building corals and other marine organisms by testing for changes in pH and calcium ion concentrations. Originally developed to inspire and recruit high school students in the state of Hawai‘i into the science, technology, engineering and mathematics (STEM) fields, we assessed the effectiveness of the activity through the responses of 380 high school students to a series of questions about ocean acidification both before and after guiding them through the inquiry-based activity. Our results show that students gain a better understanding of ocean acidification and the relevance of the geosciences to their daily lives after their participation in the activity.

Key words::

• ocean chemistry
• pH
• calcium carbonate
• coral
• climate change

Acknowledgments

The authors would like to thank Dr. Ku‘ulei Rodgers and Dr. Paul Jokiel from the HIMB Point Laboratory, and Dr. Marlin Atkinson from the Coral Reef Biogeochemistry and Remote Sensing group for their helpful contributions. Funding was provided by the Hawaiian Islands Humpback Whale National Marine Sanctuary (MOA-2005-008 Amend. 002/7189) and the National Marine Sanctuary Program Pacific Islands Region (MOA-2005-008 Amend. 004/7471). We would also like to thank the HIMB Community Education Program volunteers for providing additional comments and suggestions.

FIGURE 1: Three chemical equations essential to hypothesizing how ocean acidification may affect certain marine organisms (see text for explanation).

FIGURE 2: Example data showing changes in (A) pH and (B) calcium ion concentration after adding CO₂ to seawater with corals skeletons.

FIGURE 3: Compiled data from 380 high school students indicating their responses to each of four multiple-choice questions related to the topic of ocean acidification (A–D) as well as a question about hypothesis formulation (E). Each graph shows the number of students that selected each potential response both before (black bars) and after (white bars) completing the inquiry-based experiment. ** indicates the correct response.

TABLE I: Materials for Day 2.

TABLE II: A list of common household items and their expected pH.