Pollution of the Seine hit salmon numbers after World War I

Wild salmon are returning to the French capital for the first time in almost a century, scientists say.

Historically, Salmo salar - or Atlantic salmon - used to migrate up the Seine river for part of the year to spawn.

But increased pollution of the water and the building of dams after World War I saw their number dwindle.

By 1995, the salmon were gone, and only four species of fish braved the Seine's dirty waters, which washed up hundreds of tonnes of dead fish a year.

But a major clean-up project in the past 15 years - including the building of a water purification plant - has turned the tide for the river's marine life.

Now the Atlantic salmon - listed as an endangered species throughout Europe - is back, as attested by anglers who have netted sizeable specimens from the river in recent months.

And the salmon are not alone. Hundreds of sea trout, shad and lamprey eel have been spotted glinting in the Parisian sunlight this year, with the number of fish species in the river ballooning to 32, officials say.

"This year the numbers have exceeded anything we could have imagined," said Bernard Breton, secretary-general of France's National Federation for Fishing.

"I would not be surprised if we had passed the 1,000 mark [for salmon]," he told AFP news agency.

Scientists at the French National Institute for Agricultural Research say the return of the salmon is significant - it is a "bellwether species" giving signals about its habitat's state of health.