The Waddenzee should be closed to commercial shipping during storms to protect the ecosystem off the Dutch coast, MPs have been told.

Fred Soons, professor of international law at the university of Utrecht, said laws could be passed allowing emergency measures to prevent container ships running aground in the shallow water.

In January last year the MSC Zoe shed 345 containers loaded with equipment and toys in plastic packaging that washed up on the Wadden Islands, causing a natural disaster. A month ago a Dutch vessel, OOCL Rauna, lost seven containers, though they mainly contained paper and non-toxic materials.

Infrastructure minister Cora van Nieuwenhuizen said ordering container vessels to stay out of the Waddenzee was complicated because the area crosses an international boundary with Germany.

Soons said: ‘When it comes to international law you can’t impose permanent measures unilaterally. But there are temporary solutions for specific cases.’