Moreover, to get a better estimate of the occurrence of microplastics in the environment, the extracts from river and sea were investigated by Raman microscopy (see details in the experimental section). SEM images of extracts from Baltic Sea and Warnow River are shown in Figure and Figure , respectively. According to the Raman spectra, microplastics are present in the extracts. For instance, for the extract from Warnow River, there are 8 microplastics out of 1542 particles, including polypropylene (PP), polyethylene (PE), polystyrene copolymer, polytetraflouroethylene (PTFE), polyethylene terephthalate (PET) and pigments (more details in table ).