Seasonal Variations of Dissolved Organic Matter Bioreactivity in New Jersey Coastal Waters
McKenna Fernandini
Co-Presenters: Individual Presentation
College: The Dorothy and George Hennings College of Science, Mathematics and Technology
Major: Biology/Enviornmental Option
Faculty Research Mentor: Shuting Liu
Abstract:
Located near urbanized areas, New Jersey coastal waters connect human and natural biological activities which impact the level of dissolved organic matter (DOM) and its bioreactivity in the water. New Jersey Barnegat Bay is a brackish water body that receives runoff of both inorganic and organic matter from surrounding towns. The increasing amount of human-induced inorganic nutrients found in coastal waters trigger algal blooms, which affect DOM dynamics and bioreactivity at vary times during the year. Amino acids can be used as an indicator for DOM bioreactivity in water. This research was conducted to determine the levels and composition of amino acids in the Barnegat Bay over two seasons (spring-summer versus winter). Samples were taken at various times throughout the year from surface water at two locations along the bay. Hydrochloric acid was used to perform hydrolysis of water and thereafter the hydrolysate samples were run through high performance liquid chromatography (HPLC). The concentrations of amino acids and amino acid % in bulk dissolved organic carbon were higher during the spring-summer months versus the winter months, corresponding to algal blooms occurring during the spring-summer and suggesting that there are more sources of bioreactive DOM in the warmer months. Amino acid compositions also revealed less degraded DOM in the spring-summer time, indicating different sources of DOM between seasons. Understanding DOM sources and bioreactivity is crucial to decipher the carbon cycle and its relationship to anthropogenic and in situ microbial activities.