Abstract: Biodiversity is crucial factor in determining the stability of the environment. We wish to determine the differing fish biodiversity contributions of three separate feeder streams emptying into Patchogue Bay. We will examine water samples from feeder streams proceeding from three adjacent locations on Long Island: Great Patchogue Lake, Little Creek, and Swan Lake. Each of these locations differs in human population density and will consequently differ in pollution levels. The feeder stream from Great Patchogue Lake is has a plethora of seafood restaurants, yacht clubs, and marinas, which we perceive will bring the highest amounts of nitrogen levels and other harmful pollutants to Patchogue Bay. Thus, if one specie(s) of fish is prominent within a particular location, a lurking factor such as pollution may be affecting that area’s biodiversity. The feeder stream from Little Creek runs through a public park, which is state supervised, thus expected to be lower in overall pollut