Expedition discovered more plastics in the Scheldt than in the North Sea (Antwerp)
The Scheldt contains considerably more micro and macro plastics than the North Sea. This is the conclusion of a study by the Flanders Marine Institute (VLIZ). The conclusion conflicts with international studies that state that 80 percent of the plastics in the seas come from the rivers.
Last week, VLIZ organized its first expedition to investigate the impact of litter, climate change and the loss of biodiversity. That in salt, brake and fresh water. Research vessel Simon Stevin sailed from Ostend, via the Western Scheldt to Antwerp and the Sea Scheldt to Sint-Niklaas.
Four to eight times higher
During the expedition, the concentration of macro- and microplastics varied between salt, brake and fresh. In the freshwater part of the Scheldt (the Zeeschelde), the plastic part is four to eight times higher in the surface water than in the brackish part, the Western Scheldt and the saline North Sea. The differences are smaller in the soil, but here too the proportion of plastics is higher in the river than in the sea.
Accumulations
This is important because international studies show that seas are polluted by the waste that flows into the sea via rivers. “These are Asian Asian studies,” says Jan Seys statement. With us, the plastics do not seem to flow through, but it lingers. The Scheldt is a lowland river with little gradient. The plastics do not end up in the sea, but are accumulated in the river by tidal action. “That is our suspicion. More research and more attention are needed to clean plastics in the river.”
For the plastics that were found in the sea, the rivers were not found to be the main source. “We also learned that from this expedition. For plastics at sea, we have to look at other sources such as shipping, beach tourism and aquaculture. They may be more burdensome than expected.” (again)