By: Sarina H.
Year: 2023
School: Kraemer Middle
Grade: 7

Freshwater acidification is a growing concern globally, with significant attention focused on understanding its potential impact on aquatic ecosystems. While extensive research has been conducted on ocean acidification due to rising carbon dioxide levels, less attention has been given to its freshwater counterpart. This science project aims to bridge this gap by investigating the effects of freshwater acidification on the heart rates of Daphnia Magna, a small but vital organism in freshwater ecosystems.

The primary goal of Sarina’s experiment is to determine whether changes in pH levels in freshwater environments impact the heart rates of Daphnia Magna. With freshwater acidification emerging as a critical issue, this study provides valuable insights into the potential health effects on organisms inhabiting freshwater environments.

Sarina’s hypothesis posits that decreasing the pH of the water will lead to an increase in the heart rate of Daphnia Magna. This prediction aligns with existing studies related to acidification in other organisms.

To test the hypothesis, Daphnia Magna were introduced into five containers, each with varying pH levels (6, 6.5, 7, 7.5, 8). Lemon juice was used to alter the pH levels of the water, mimicking the acidification process. The heart rates of the Daphnia Magna were measured every 24 hours over a four-day period.

Upon completion of the experiment, the data revealed a correlation between decreased pH levels and increased heart rates of Daphnia Magna. The average heart rates for each pH level on the fourth day were as follows: 315.75 (pH 6), 288 (pH 6.5), 268.5 (pH 7), 269 (pH 7.5), and 265 (pH 8). Interestingly, no consistent trend was observed within each pH value from day 1 to day 4.

This experiment successfully supports the hypothesis that decreasing the pH of water leads to an increase in the heart rate of Daphnia Magna. The results underscore the importance of addressing freshwater acidification and its potential consequences on aquatic organisms. By understanding these effects, scientists can contribute to conservation efforts aimed at protecting the delicate balance of life in freshwater environments. This research serves as a crucial stepping stone in the broader conversation surrounding environmental conservation and the well-being of freshwater ecosystems around the world.