Bachelor Thesis

Can micro-plastics provide information on hyporheic zone characteristics?

Laura Wilhelm (07/2016-09/2016)

Support: Sven Frei, Ben Gilfedder

Micro plastics are currently at the frontier of contaminant research and ecosystem response to human practices. They are increasingly being incorporated into consumer projects such as sunscreen, toothpaste and body creams. They are also formed as plastic degrades in the environment. While they are potentially detrimental or even toxic to organisms in natural ecosystems, they have the potential to be used as an anthropogenic tracer for interactions between groundwater and surface water. In particular, they may be able to show how far surface water penetrates into the hyporheic zone, a parameter that is otherwise very difficult to measure using standard techniques. But what is the hyporheic zone? The hyporheic zone is the interface between groundwater and surface water systems. It is a ‘hot-spot’ for biogeochemical reactions such as nutrient processing, and an important niche for aquatic organisms, particularly invertebrates. It can provide refuge for aquatic organisms during high or low water, and is also home to endemic species that inhabit this interface. This project aims to determine if micro plastics are present in the sediments in streams near Bayreuth (e.g. Rote main and Mistelbach) and if micro plastics can be used to trace water flow paths and depths in the hyporheic zone. This project has implications for our understanding of the distribution of micro plastics in the environment and how they may be able to be used to characterise water flow paths in the hyporheic zone. This information will be incorporated into an ongoing project masters on nutrient processing and water residence times in the hyporheic zone along the Rote Main. The project will be run in cooperation with Prof. Laforsch (Tierökologie)