Contamination of aquatic ecosystems with plastic debris: global and local monitoring using remote sensing methods
One of the most omnipresent and long-lasting human induced changes of the earth is the accumulation and fragmentation of plastic debris in the aquatic
environment. Due to the high spatio-temporal variability of floating plastic debris, there is still little information about sources, sinks, and transportation pathways. Earth observing remote sensing is a key technology within the field of environmental monitoring. Therefore, this project aims to assess the potential of remote sensing technologies as a monitoring tool for plastic debris in aquatic environments. With a combination of field, laboratory and remote sensing methods the following aspects will be examined:
1) input and transport of plastic debris by selected rivers,
2) distribution patterns in estuaries and adjacent coasts,
3) as well as distribution within the ocean gyres.
Due to the characteristic absorption features of polymers within the SWIR (short-wave infrared spectral region of the electromagnetic radiation), a direct identification and quantification of floating plastic debris through hyperspectral images will be investigated. Furthermore an indirect approach will be tested, as it is assumed that smaller plastic particles (microplastic <5mm) likely will not have a significant influence on the reflected spectrum. Thereby, correlations between plastic particles and water parameters (i.e. sediment load, sea surface temperature, chlorophyll-a) will be analyzed for their suitability as indicators for microplastic abundance. Monitoring through remote sensing could be an innovative method to collect more comprehensive spatial and temporal data. This would contribute to a better knowledge about sources, sinks, and distribution patterns of floating plastic debris in aquatic environments.
A further outcome of this project is a method for fast and automated identification of microplastics in the lab using a short-wave infrared imaging spectrometer: