Plastic litter in Norwegian lakes, rivers and coastal areas. Evaluation of monitoring methods

Summary

The report gives a review over possible environmental problems associated with plastic in the environment, with focus on Norway. Knowledge based management of this global problem will depend on data on sources, pathways, sinks and the wider fate of plastic in the environment, both locally and regionally. A main challenge is that impact of plastic on the environment is assumed to comprise of fairly different modes also biochemically because plastic litter includes a wide range of different chemical substances and additives. All these factors affect the environmental behavior and distribution of plastics. Macro plastics behave differently than for example micro- and nano plastics depending on different environmental factors. The report gives an updated state of the art based on Norwegian and international research including sources, transport mechanisms in both the fresh water and the marine environment and points out several knowledge gaps on different levels which makes it difficult to conclude and implement measures. Several environmental impacts are discussed with particular focus on the freshwater catchment areas and their role in the transportation of plastic litter to the marine environment. Furthermore, an overview is given of the methods that have so far have been tested for mapping and monitoring of plastic waste. Future monitoring of the plastic litter will partially require new technology, and several examples are discussed. Recommendations are given for prioritization and appropriate monitoring methods.