Each day we throw away our trash, but once it leaves our hands, where does it go?

Last semester, Rob Dunn’s Community Ecology of Humans class tackled this question and a number of other questions about the waste generated by humans and the process by which it breaks down (called decomposition). Graduate students Ryann Rossi and Shannon Brown were particularly interested in the transport of waste to the final location where it decomposes. They led the in-class research team that generated the figure above. Here’s what they had to say about the figure:

We know trash is moved around, and yet we do not fully understand how and where our trash moves, and what organisms move with it. Oceanic trash is transported through currents; while in transit, organisms hitchhike rides to new shores, with the potential to invade. Unlike oceanic transport, terrestrial transport of waste, and waste-associated organisms, remains largely understudied.

Movement of trash on land is intentional; it is collected from our homes and transported to a dump or sorting facility. Though the general process is known, we know little about the destination and hitchhikers associated with trash, not to mention the potential for biological invasions.

Above is a map we produced of US states that ship their trash to other states, based on data from the Congressional Research Service Report on Interstate Shipment of Municipal Solid Waste (2007). We focus particularly on Georgia, a state that receives the trash from 13 other states.

The map is eye-opening — trash is moved substantial distances. When we consider that organisms hitchhiking on the trash are also moving these distances, we must recognize the potential for these hitchhikers to invade places we never thought possible. Knowledge of what organisms are surviving these interstate journeys is critical to thinking about future invasions, and what it might mean for habitats surrounding the dump.

Thanks to Neil Mccoy for assisting with this data visualization.

Ryann Rossi is a PhD student in Dr. Craig Layman’s lab in the department of Applied Ecology at NCSU. She studies mangroves and the processes that drive them. Specifically, she is interested in the interacting effects of top-down and bottom-up processes controlling mangrove function in addition to how humans alter these systems, particularly by using them as dumps.

Shannon Brown is a Master’s student in Dr. David Eggleston’s lab in the department of Marine, Earth, and Atmospheric Science. She studies estuarine soundscape ecology, specifically spatiotemporal patterns of biological and anthropogenic sounds of intertidal habitats in a coastal reserve. In addition to soundscape characterization, she is also investigating the role of habitat-associated sounds as a settlement cue for oyster larvae.