Identification of marine microplastics collected in the Canary Islands: coastal and oceanic samples

Abstract

The existence of microplastic in the water column between 50 and 300 meters depth in the Atlantic Ocean is reported for first time. To carry on this study, some cruises near Canary Islands were done. Microplastic concentrations could be related with the density profiles. The samples are taken at different depths in a range of between 0 to 300 meters deep. A rosette with a CTD and 23 Niskin bottles were used to take these samples. Between 100 and 280 meters deep, the highest concentrations of microplastics were found. On the other hand, we have used samples of coastal microplastic, to study the colour variation of the material due to degradation process. With PANTONE® Studio app it was determined and compared with the plastic composition (determined using FTIR) and its colorimetry (through a colorimeter). With all this data we have calculated the yellowness index value of each sample and compared with Pantone code colour. The values of yellowness index are in a range between the values 17,722 and 127,874%. The optimization of this methodology lets the determination of yellowness index in a simpler way using just a mobile app.