Eutrophication and causation: An investigation of potassium nitrate and algae growth

Abstract

Eutrophication refers to the addition of excess nutrients in a body of water. This phenomenon has existed naturally for centuries, but the increase in commercial farming has dramatically increased levels of Eutrophication worldwide because fertilizers contain nutrients such as nitrogen. Furthermore, Algal blooms have been associated with the increase of nutrient concentration in bodies of water. We tested the effects of varying concentrations of potassium nitrate on algae growth in a freshwater sample. We predicted that as the levels of potassium nitrate increase, the algae growth would increase because the abundance of nutrients will cause it to bloom and the water quality to decrease because decomposers will feed on the algae, eliminating the dissolved oxygen in the water. Overall, this prediction was somewhat supported by the data because pH level decreased, but Dissolved Oxygen decreased inconsistently with addition of potassium nitrate. As a result, algal blooms cause the production of harmful toxins and block sunlight from penetrating flora beneath the surface. Overall, this investigation showcases that cultural eutrophication by means of nitrogen-rich fertilizer runoff is detrimental to overall water quality.