Thousands of salmon escaped an Icelandic fish farm. The impact could be deadly

Aquaculture is bringing jobs and money to rural regions, but a huge escape of farmed fish in August could devastate local salmon populations

Clad in black waders, Gumundur Hauker Jakobsson jumps into the River Blanda, whose freezing waters run down from the Hofsjokull glacier. Armed with a net, he casts around the ascending pools of the river's fish ladder", built to aid wild salmon migrating up this powerful waterway from the sea.

Within minutes, he pulls out a 15lb silver fish, which thrashes and writhes against the net, then another, then another - five in all. The wild salmon of the Blanda here in north-west Iceland are some of the largest and most athletic in a country where the rivers are considered among the world's best. King Charles has fished for salmon here, as have David Beckham and Guy Ritchie; Eric Clapton is a regular.

Gumundur Hauker Jakobsson draws a salmon from the river