PT25 - CC - Ocean acidification on marine organisms

The students were divided into 3 teams, and each team into 3 groups in order to develop some experimental activities related to the problem of global warming, ocean acidification and sustainability. There was a initial introduction to the theme by telling them that Carbon dioxide (CO₂) is released into the atmosphere through human activities (burning fossil fuels, deforestation, industries, etc.). A portion of this CO₂ is absorbed by the oceans, where it reacts with water to form carbonic acid (H₂CO₃). This acid lowers the pH of the water, making it more acidic, a phenomenon known as ocean acidification.

Acidification affects marine life, especially organisms that produce shells and skeletons made of calcium carbonate (CaCO₃), such as corals, mollusks, and plankton. In order to test the acidification effects, students contacted with laboratory techniques of water analysis, using water, vinegar and eggshells.​ They analyzed the effect of increasing acidity on calcium carbonate-based structures by measuring the mass loss of eggshells in different acidic environments.​

They used a precision balance to measure the mass of the eggshell pieces at the end of the experiment.​

During the experiment, the students drew a labeled diagram of what they observe happening in each beaker.​

They had able to identify the control setup, identify the role of vinegar and the eggshells in this experiment, and conclude that the vinegar simulates the effect of carbonic acid in the oceans.​

At the end, students should conclude what they learned from this experience.