The sighting is particularly significant, experts say, because the water trout is highly sensitive and demanding about the quality of water in which it swims. The fact that it is now able to live in the Seine is proof of the river's constant improvement in quality, they said.
The trout, which is thought to have swum upstream all the way from the Seine estuary on the English Channel coast, was fished last weekend by a couple in the western outskirts of Paris. Amazed at their unusual catch, the anglers contacted the SIAAP to find out if it was a first for the river.