'Europe's first dead river' Ukraine blames Russia as toxic slick causes disaster

Serhiy Kraskov picked up a twig and poked a small fish floating in the Desna River.

- Luke Harding ,Artem Mazhulin

"It's a roach. It died recently. You can tell because its eyes are clear and not blurry," he said. Hundreds of other fish had washed up nearby on the river's banks. A large pike lay in the mud. Nearby, in a patch of yellow lilies, was a motionless carp. "Everything is dead, starting from the tiniest minnow to the biggest catfish," he added mournfully.

Kraskov is the mayor in the village of Slabyn, in Ukraine's northern Chernihiv region. The rustic settlement, which has a population of 520, has so far escaped the worst of Russia's fullscale invasion. But the war arrived last week in a new and horrible form. The Russians, Ukrainian officials say, deliberately poisoned the Seym River. It flows into the Desna, which connects with a reservoir in the Kyiv region and a water supply used by millions.

A toxic slick was detected on 17 August coming from the Russian border village of Tyotkino. According to Kyiv, chemical waste was dumped into the Seym from a sugar factory in vast quantities. It included ammonia, magnesium and other poisonous nitrates. At the time, fierce fighting was going on in the surrounding area. Ukraine's armed forces had launched a surprise incursion into Russia and had seized territory in Kursk oblast.

The pollution crossed the international border 1.2 miles away and made its way into Ukraine's Sumy region. The Seym's ecosystem crashed. Fish, molluscs and crayfish were asphyxiated, together with river weeds, as oxygen levels fell to near zero. Settlements along the river reported mass die-offs. Kraskov got a call from the authorities warning him a disaster was coming his way. He spotted the first dead fish on 11 September.