IMIS

Therefore, the Ecosystem Management Research Group of the University of Antwerp, is studying the potential contribution of the Scheldt river to the worldwide “Plastic Soup”. In this project the focus is on macroplastics (≥2.5cm). For this fraction it is still realistic to design removal strategies in rivers, the ultimate goal of this study. To date, samples have been taken in the river using different techniques like: fyke nets, a fishing technique called anchor netting and a specially designed “combination sampler”. The latter allows to study the vertical distribution. Additionally clean up’s have been organized to study the composition of plastic waste that ends-up on riverbanks. The data collected so far, has provided crucial insights, but many questions remain unanswered. To answer such questions as: “How long does it take for plastic to end up in the North Sea?” and “What factors determine why some types of plastic or found more on riverbanks than in the river itself?”, it was decided to follow marked items on their journey through the estuary of the Scheldt river (Belgium). On December 17th 2019, a first step was taken by the release of 972 bright yellow plastic items into the Scheldt river. These items, of various types of plastic released at 3 locations (Melle, Dendermonde and Wintam), are equipped with a unique code and are part of a citizen science project. If found on a riverbank, the item can be registered through the website www.zpr.one. Simultaneously 3 GPS trackers were launched. Yet, each of these methods has it’s own advantages and disadvantages. GPS trackers deliver very detailed information but can only be used to track floating items. On the other hand, tracking items as part of the citizen science project, allows a large variety of items to be tracked (floating and submerged items), but it is required that they end up on a riverbank first, are found and are registered correctly. On June 30th 2020, a next step was taken. Again, new batches of bright yellow plastics are released into the Scheldt river, together with 6 GPS trackers. In addition, 30 items of various composition and shape will be fitted with Vemco V7 acoustic tags. These tags will allow us to follow certain types of submerged plastics in higher detail than possible in the citizen science project. To our knowledge it is the first time ETN’s Acoustic Receiver Network is used to track plastic items