Flanders prevents ecological disaster in Scheldt river

Flanders has been saved from an ecological disaster on the river Scheldt. A co-ordinated effort has prevented pollution from a sugar refinery in France from flowing down the river.

The collective effort involved government agencies, the civil security and fire services, and companies such as Air Liquide, Aquafin, Ghent Dredging and De Brandt. “We successfully rolled out the largest ecological rescue action ever seen on our waterways,” said Lydia Peeters, Flemish minister for public works.

The material released from the refinery at Cambrai on 9 April is not toxic, but results in bacteria sucking all of the oxygen out of the water. In these conditions, fish and other aquatic life simply suffocate.

“Almost the entire stock of fish in the Scheldt on French and Walloon territory has died,” said a joint statement released on Monday by the Flanders Environment Agency, De Vlaamse Waterweg and the Agency for Nature and Forests.

In order to avoid the same thing happening in Flanders, steps were taken to track the pollution as it flowed down stream. This allowed targeted action to be carried out, such as pumping additional oxygen into affected water.

When too late for the water to be treated, fish were pulled out of the water and moved to safety. It was easy to capture the fish, as they were gulping for air at the surface of the river.

Side channels unaffected by the pollution were shut off from the main river where possible, both for their own protection and to create reserves of oxygenated water that could later be used to dilute the pollution. Extra water was also pumped into the Bossuit-Kortrijk canal and returned to the polluted Upper Scheldt by means of sluices.

Meanwhile, barrages and locks on the Ringvaart around Ghent protected the city centre, the Upper Zeeschelde and the Leie tourist area from the pollution. “The comprehensive approach has ensured that Flanders only had to clear a limited number of fish from our waterways,” the agencies said.

“However, the fish that died in the French and Walloon part of the Scheldt are carried along with the current into Flanders, and it may take several days to clear these up.”

One odd side-effect of the incident is that we now know that shad, a migratory fish from the herring family, have returned to the Scheldt after some 100 years of absence. Staff from the Institute for Nature and Forest Research found one among the dead fish over the weekend, 200 kilometres from the sea.

“Never before have shad been caught so far inland,” the agency said. “This confirms that Scheldt waters are improving and once again form a route for migratory fish species.”

Photos, from top: Courtesy Jan Beeldens/Twitter, courtesy Azul Brazo/Twitter