One of our courses here at the Highlands Field Site is our Capstone course, Analysis and Solution of Environmental Problems. This course centers around working together as a class to conduct research and then present our findings at the end of the semester. This course revolves around studying microplastic concentrations in the rivers and streams of the Chattooga watershed and how they change during storm events. The data we gather will allow us to understand the levels of microplastic pollution in the Highlands area and also will be the first research of its kind done in the Southeastern United States!
Our research involves taking samples of the river water during storm events and then analyzing the samples at a Western Carolina University lab to determine the concentration of microplastics in the river water and how those levels change throughout a storm event. In order to collect these samples, we will be using ISCO water samplers, which are devices that collect data on the river water and can be programmed to take water samples at random time increments. We set these machines up at two different sites during the second week of classes, the first site being at Sliding Rock and the second located just downstream from the Cashier’s wastewater treatment plant.
The actual process of setting up the ISCO devices was time consuming but still very enjoyable. We first had to scout out the locations to find a site where we could leave the ISCO devices without having them stolen or damaged. At both sites, we were able to hide the ISCO devices within some rhododendron thickets. Then we programmed the machines, which included telling the device to collect the right sample volume and how often to collect samples. We also staked the sample collection tube and sensor into the river bed in order to keep them in place and under the water. While some of us were setting up the ISCO samplers, others used surveying equipment to take a river bed profile and find the slope of the water. We can now use the data that we collected to determine the discharge of the rivers.
Another part of the research project is tracking the deposition of microplastics from the atmosphere by atmospheric deposition collectors, or metal buckets. We installed two buckets, a sealed control bucket and an open collector bucket, at each of the ISCO sites, plus one at a fellow student’s property located in Cashier’s. We will leave the collectors at each site for one week. After a week has passed, we will come and collect them, while sealing them to make sure that no excess microplastics from our clothes fall into the buckets. We will then count how many microplastics have entered the collector buckets over that time period and compare that microplastic concentration to the control bucket in order to determine a rate of atmospheric deposition of microplastics. We can then determine how many of the microplastics that we find in the water samples from the river came from the atmosphere and how many came from runoff.
We have yet to collect any samples during a storm event, but we have still collected one set of buckets and some water samples. In fact, we will be analyzing at WCU next week! This research will provide some insight on a pollution source that often goes unrecognized and under-studied in our region. We should hopefully be able to make some powerful conclusions of how and when microplastics are entering river systems. We will make sure to update you on our progress throughout the semester!