Project cost ($):
1 hour to prepare, 8 hours for experiment
Table of Contents
This experiment was performed to ascertain the effect of aquatic plants on the acidity levels of our oceans. Carbon dioxide levels in our atmosphere have been on the rise mainly due to the burning of fossil fuel and deforestation. The results of this experiment will ascertain whether aquatic plants help to reduce the acidification of our oceans, via the process of photosynthesis.
Increasing the amount of aquatic plants in the aquarium will reduce the acidity and increase the pH level of the water.
Aquatic plants and animals
Aquatic plants photosynthesize under water. They absorb the carbon dioxide in the water and release oxygen. This helps to increase the oxygen content in the water, which is then used by aquatic animals for respiration. Through respiration, both plants and animals take in oxygen and release carbon dioxide.
This underwater process of the exchange of gases is very similar to the photosynthesis by plants on dry land, and the respiration by both land plants and animals.
The ideal pH level for fishes is between 6.6 to 7.4 whereas the ideal pH level for aquatic plants is between 6 to 9.
Industrialization and human activities such as deforestation and burning of fossil fuel has led to increased levels of carbon dioxide in the air. Part of this carbon dioxide is absorbed by the ocean, thus reducing its pH levels and making it more acidic. A pH drop from 8.18 to 8.10 has been recorded over a period of 250 years.
If this trend should continue, marine life may be adversely affected and this will create a domino effect which will ripple up through the food chain and eventually affect man to a great extent.
Photosynthesis, respiration, pH
The results show that the acidity in the water will increase if there are only fishes and no aquatic plant. Increasing the number of aquatic plants help to reduce the acidity of the water.
Use the below graph to plot the results of above observation.
The hypothesis that increasing the amount of aquatic plants in the aquarium will reduce the acidity and increase the pH level of the water is proven to be true. The aquatic plants use carbon dioxide in the water for photosynthesis and therefore reduce the acidity of the water.
The experiment can also be repeated without the fish. Try to add some corals into the water.