MICROPLASTICS’ EFFECT ON THE MELTING BEHAVIOUR OF LAKE ICE

Abstract

Research regarding lake ice and microplastic is very limited. It is not known exactly how microplastics interact with lake ice nor how they affect it. As lake ice plays an important role both for natural ecosystems and for humans, it is of great value to understand how microplastic might affect it. This study investigated how microplastic affects the melting behaviour of lake ice by producing artificial columnar ice cores in a laboratory environment both with and without microplastic. UV-vis-NIR absorption spectroscopy was used to compare if a difference in absorbed light, and thereby energy could be detected between the two types of samples. Artificial columnar ice cores were produced in an ice laboratory at University of Gothenburg in Sweden. Three types of microplastics dyed with black, green, or red dye were added to the ice cores. Light absorption measurements were done using a spectrometer. Samples with lower concentration of microplastic showed a higher absorption than samples without microplastic. Samples with higher concentration of microplastic in the colour green showed a higher absorption of UV radiation between 188-240 nm and throughout the visible and near infrared spectrum compared to samples without microplastics. Samples with higher concentration of red plastic showed less absorption of UV radiation between 188-240 nm and higher absorption throughout the visible and near infrared spectrum compared to samples without microplastic. Samples with low concentration of one type of black microplastic and high concentration of two different types of green microplastic had higher total energy absorption than samples without microplastic. The results suggest that more light and thereby energy is absorbed by artificial columnar ice cores containing microplastic compared to columnar ice cores without microplastic. This study is a first step to investigate the effect microplastic has on the melting behaviour in lake ice and more research is needed.