The Effect of Increased Nutrient Availability on Freshwater Phytoplankton Growth

Benjamin Ronald Janitz, Marc Gaydos

This study examines the impact of nutrient enrichment on phytoplankton biomass and water chemistry in pond water samples. Three concentrations of organic fish fertilizer (0 µL, 10 µL, and 20 µL per 10 mL of pond water) were tested over 18 days under constant illumination. Phytoplankton biomass was spectrophotometrically measured at 750 nm, with pH and turbidity also assessed to evaluate changes in water quality. The results indicated that increasing nutrient concentrations resulted in enhanced phytoplankton growth, as evidenced by reduced light transmittance and increased turbidity. Higher fertilizer levels also raised pH values, suggesting greater photosynthetic activity and more alkaline conditions. These findings support the hypothesis that nutrient enrichment stimulates primary production, although it may also contribute to eutrophication processes. Overall, the experiment provides valuable insights into how localized nutrient inputs influence aquatic ecosystems and highlights the relationship between nutrient availability, algal biomass, and water chemistry.