Source Identification of Nutrient Impairment in North Biscayne Bay, Florida, USA

Abstract

The limiting nutrient in North Biscayne Bay identified using the Redfield ratio does not correspond to a significant quantitative relation between measured concentrations of the identified nutrient and chlorophyll a. Strategies for reducing chlorophyll a could focus on the nutrients that are significantly correlated with chlorophyll a. To identify the terrestrial sources of nutrient loads, a novel application of the load-duration curve (LDC) is shown to effectively differentiate between surface runoff and groundwater sources of nutrients in urban drainage canals. It is shown that septic tanks and stormwater-management exfiltration trenches can yield comparable nutrient loadings to groundwater, which might subsequently impact nutrient concentrations in the adjacent bay.