No study to date has catalogued NYC’s algal species across a nutrient pollution gradient using DNA barcoding. The purpose of this project is to employ DNA barcoding to compare algal communities between nutrient-rich and nutrient-poor waters in NYC. We will test whether high nutrient levels correspond to lower algal diversity and the presence of specific indicator species, relative to low-nutrient (oligotrophic) conditions. The findings will demonstrate the utility of DNA barcoding in urban water quality assessment and address how nutrient pollution influences not just algal biomass, but the composition of algal species.