Norway reveals plans for river trap system to protect wild salmon

Announcement comes as Scottish report says open-pen salmon farms pose substantial risk to wild population

Norway is to introduce new traps to protect wild salmon after experts warned they could become endangered as a result of contact with their farmed counterparts.

Farmed fish and non-native pink salmon carry various diseases and lice, and in recent years have spread from Russia across the Norwegian coastline, reaching Britain and mainland Europe.