The purpose of this experiment is to find a way to reduce the effects of low oxygen levels in the ocean, called dead zones. To find a solution to this problem, the chemical Aluminum Sulfate (Al2(SO4)3 was employed to reduce the levels of Phosphate in water. The Phosphate and other fertilizers are what catalyzes the development of dead zones. By adding Aluminum Sulfate, the growth rate and population of our sample organism, the protist Euglena, and Chlamydomonas was reduced.
Population growth rates and levels were measured by using a machine called a spectrophotometer. This machine measures the amount of light that is transmitted through a sample of water. Thus the more light that passes through, the less organisms it contains. Initially, the level of all 22 culture dishes was at a level of 90 transmission, but by day four, the level had decreased to around 35 in some dishes. Once the Aluminum Sulfate was introduced, transmission levels increased. Population levels decreased by 10% to 20%.
To add another variable to the experiment, different levels of miracle grow (phosphate) were used. In four of the dishes (per protist), a level of 1% was used. Another four used 2% (per protist). The result of the former was an increase in growth of both protists. The latter groups showed a much lower transmission rate.
By reducing the amount of phosphate in the water, the data indicated that the growth rates of Euglena can be controlled through the addition of aluminum sulfate. Other than the initial transmission levels going back up, the overall appearance of the dishes clearly show the population levels going down as well. At the beginning of the experiment, the dishes had a yellow hue to them. As the protists grew, it created a greenish hue, which gradually faded to close to the original yellow, but still retains quite a bit of green.
The experiment itself has been conducted, but I am wondering if there could be anything that I could do to further the experiment. Spectrophotometry proved the results of dead zones can be reversed by using Aluminum Sulfate, but is there an alternative? Perhaps a cheaper one?