Scotland's native salmon could be under threat from an invasive species.

Rivers which should be home to Atlantic salmon are being increasingly populated with the Pacific breed, leading to concerns over the species' future.

Pacific, or pink salmon, have been caught in unprecedented numbers in rivers across the north of Scotland.

It is not yet known how big an impact on local stocks the Pacific salmon could have.

Anglers are being told by Fisheries Management Scotland to report and record any sightings of the fish to monitor their impact on the environment.

A representative from the Ness District Salmon Fishery board, Chris Conroy, said: "We're asking any anglers to look out for them, if they catch them, to retain them so we can take some samples, genetic samples and also scale samples from these fish.

"At the moment that's all we can really ask people to do. They are being caught on numerous rivers across Scotland.

"They've been caught in the river Helmsdale, the River Esk and the River Dee and even some of the rivers in northern England."