Input of Anthropogenic Debris Across a Rural to Urban Gradient in the Lake Ontario Watershed

Anthropogenic debris (AD) is now ubiquitous across terrestrial, marine, and freshwater environments. While plastic is typically the dominant material in AD, non-plastic materials, including metal, glass, processed wood, and concrete, are a large part of the diverse debris entering and moving through the environment and may have similar environmental impacts. Current estimates of plastic entering the Great Lakes are coarse and none exist for other AD. This gap precludes development of source-based mitigation plans. This study evaluated debris quantity and composition in tributaries and storm sewers entering the Rochester Embayment of Lake Ontario. Using LittaTraps™ installed in storm drains, we evaluated the quantity and composition of debris entering the stormwater system in the City of Rochester and Town of Brighton, New York. The mass and composition of debris in LittaTrap™ samples were highly spatially variable, even among nearby sites. Patterns of input generally followed land use and land development, with high organic debris in residential areas, and high quantities of plastic and cigarette butts at some urban sites. In addition to tobacco-related debris, the most common products were associated with snack wrappers and other miscellaneous plastic debris. Macrodebris (>5 mm) transport in tributaries was very low, but higher during storms. Microdebris particles (< 5 mm) were not identified to polymer type, but showed some relationship with land use: suburban sites were generally higher than rural sites. Fibers were the most dominant microdebris by morphology. Our results illustrate the complexity of AD composition and highlight specific sources, especially in urban areas, where mitigation measures may be effective in reducing input and potential downstream harm.