Examples of The Science of Ocean Acidification

Understanding Ocean Acidification

Ocean acidification refers to the decrease in pH levels of the ocean caused primarily by the absorption of carbon dioxide (CO2) from the atmosphere. This phenomenon poses significant threats to marine ecosystems, particularly to organisms that rely on calcium carbonate to form their shells and skeletons, such as corals and shellfish. In this article, we will explore three practical examples of the science behind ocean acidification that can serve as engaging science fair projects.

Example 1: Investigating Shell Growth in Marine Organisms

In this project, students can explore how ocean acidification affects the growth of shells in marine organisms such as clams or snails. The use case for this experiment lies in understanding the biological implications of changing ocean chemistry on shell-forming organisms, which are vital to marine food webs.

To conduct this experiment, students will need:

• Several identical tanks filled with seawater or saltwater solution.
• Equipment to measure pH levels (pH meter or strips).
• Marine organisms (e.g., clam or snail species).
• CO2 source (e.g., vinegar or a CO2 generator).

The process involves:

1. Setting up the tanks at different pH levels by gradually increasing CO2 concentration in the water.
2. Introducing the marine organisms into each tank and allowing them to acclimate.
3. Measuring shell growth over a predetermined time period by taking periodic measurements with calipers.
4. Analyzing the data to determine the correlation between ocean acidity and shell growth.

Notes: Consider using a control group with normal pH levels to compare results effectively. Variations can include testing different species or adjusting temperature conditions to see how they interact with acidity.

Example 2: The Effect of Ocean Acidification on Coral Reefs

This project focuses on how ocean acidification impacts coral reefs, which are highly sensitive to changes in their environment. The context for this experiment is to highlight the ecological importance of coral reefs and the consequences of acidification on biodiversity.

To execute this project, students will need:

• A small aquarium setup.
• Live coral fragments or coral-like structures.
• pH measurement tools.
• CO2 source to create different acidity levels.

The experiment can be structured as follows:

1. Create an aquarium environment that mimics coral reef conditions, including proper lighting and water temperature.
2. Set up multiple tanks with varying pH levels by adding CO2 gradually.
3. Introduce coral fragments into each tank and monitor their health over time.
4. Observe and record changes in coral color, growth, and overall health, noting any bleaching events related to acidity levels.

Notes: Students can also assess the effects on symbiotic algae (zooxanthellae) within the coral, which are crucial for coral health. Variations may include experimenting with different types of coral or introducing additional stressors like increased temperature.

Example 3: Measuring Carbonate Ion Concentration

This project entails measuring the concentration of carbonate ions in water samples from different sources to understand the relationship between CO2 levels and ocean acidification. The context is essential for grasping how ocean chemistry changes and the impact on marine life that relies on carbonate ions.

Materials required include:

• Water samples from various environments (e.g., ocean, freshwater, estuary).
• Equipment for measuring carbonate ion concentration (such as a titrator or spectrophotometer).
• pH measurement tools.

The approach for this project is:

1. Collect water samples from different locations, noting their environmental conditions.
2. Measure the pH of each sample and record the data.
3. Use a titration method to determine the concentration of carbonate ions in each sample.
4. Analyze the relationship between pH and carbonate ion concentration, illustrating how increased CO2 leads to lower carbonate availability.

Notes: To enhance the experiment, students could compare results over time to see seasonal variations or include historical data if available. Variations could involve different testing methods or water sources to broaden the comparison.

Through these examples of the science of ocean acidification, students can engage with real-world environmental issues and develop a deeper understanding of marine ecosystems and their vulnerabilities.