Uncovering regional differences in plastic pollution distribution along the Norwegian coast

Abstract Understanding the mechanisms behind coastal plastic accumulation is crucial for more targeted clean-up actions and policy-making. We used a systematically collected dataset for plastic pollution along the Norwegian coast, added physical and socio-environmental response variables to it, and used linear regression to identify the most important factors that influence plastic accumulation. We used 446 sampling transects on 170 beaches from Norway’s south-eastern, southern, western and northern coasts. Plastic weight and count were chosen as response variables in several linear models, with different explanatory variables included. Although the explained variance in plastic pollution did not lead to any meaningful insights regarding plastic distribution, other insights were gained. Measuring plastic pollution by weight or item count led to different correlations of predictor variables. There were significant regional differences in models, and some predictor variables clearly show different values depending on the region. Furthermore, geographical beaching patterns of different types of plastic debris along the Norwegian coast found in the literature were confirmed. The southern coast had the largest number of plastic items per sampling area, whilst the north displayed fewer but heavier items. Dividing the data by region seems to be desirable, but more samples per region are needed.