Samenvatting

Today the awareness about anthropogenic waste and litter in the marine environment is rising. There is evidence on the threat to marine ecosystems through plastic litter, all over the world. To understand this issue better citizen science projects, help to gather data about the distribution and origins of marine plastic litter. One goal of this study was to monitor macro plastic litter study on the coasts of Zeeland. Citizen scientists were recruited who used the OSPRA and the Litterati app methods for categorisation of macro plastic litter on 3 beach locations at the Western Scheldt and 2 beach spots at the Eastern Scheldt. During this study 278 plastic items were found on the 100m stretches on average. 99% of the categorised litter was made from plastics and 60% originated from the fishing industry or offshore activities.
The majority have been blue strings and chords (VisPLuis) originating from fishing nets. The two monitoring methods yielded comparable results regarding the litter composition. The Litterati app method was received slightly more convenient by the citizen scientists and more items were picked up on average than with the OSPAR method. Weather conditions and the motivation of the citizen scientists were driving the quantity and the quality of the monitoring. A comparison of our monitoring results with a previous 5 years study at other beaches was difficult because of too many distinct factors that may have influenced the results.
Complementary to the method comparison, the participants filled in a survey regarding their motivation, experience and assessment of both methods. Most participants were motivated to join the project for environmental interest and the opportunity to contribute to a good cause. Offering incentives like study credits motivated the students as well. Using universities or schools as a source for recruiting citizen scientists is a promising approach to organise future monitoring projects. The results of this study suggest extending the knowledge base on the plastic litter pollution in Zeeland by a long-term study including more beach locations along the Western Scheldt and the Eastern Scheldt over a period of 5 years.