This hands-on lab allows students to explore concepts and quantify effects of ocean acidification. Many laboratory activities simplify ocean acidification through computer simulations or dripping acid on nonliving materials (e.g., sea shells) but do not provide adequate opportunities for students to measure, inquire, or see real consequences for living organisms. Thus, we developed this low-cost, easily accessible experiment to imitate ocean acidification on living, calcifying organisms.

Although climate change garners the bulk of headlines, ocean acidification is an equally important issue that also results from our increasing consumption of fossil fuels. As atmospheric CO 2 dissolves into the ocean, the ocean’s pH decreases, making it increasingly difficult for organisms that build calcium carbonate skeletons to grow and thrive. Given that these marine calcifiers – such as corals, snails, shellfish, crustaceans, and plankton – often form the base of oceanic food webs and are habitat and food resources for larger oceanic plants and animals (including humans), ocean acidification poses a serious threat. In this article, we present a series of investigations that provide evidence that increases in anthropogenic sources of CO 2 contribute to the acidification of the ocean, and that an increasingly acidic ocean can negatively impact marine calcifiers.

Ocean acidification, a product of CO 2 absorption by the world’s oceans, is largely driven by the anthropogenic combustion of fossil fuels and has already lowered the pH of marine ecosystems. Organisms with calcium carbonate shells and skeletons are especially susceptible to increasing environmental acidity due to reduction in the saturation state of CaCO 3 that accompanies ocean acidification. Creating a connection between human-mediated changes to our environment and the effect it will have on biota is crucial to establishing an understanding of the potential effects of global climate change. We outline two low-cost laboratory experiments that eloquently mimic the biochemical process of ocean acidification on two timescales, providing educators with hands-on, hypothesis-driven experiments that can easily be conducted in middle and high school biology or environmental science courses.