The World Wide Fund for Nature says stocks of Atlantic salmon have reached their lowest-ever levels.

In the last 25 years, WWF says, salmon numbers have fallen from 800,000 to 80,000.

It says urgent action is needed to save the species from extinction, and wants science-based catch limits.

WWF says it is commercial fisheries in the United Kingdom and Ireland that are catching most of the salmon today.

Representatives of member governments of the North Atlantic Salmon Conservation Organisation (NASCO) are gathering in Canada for the group's next meeting.

Its members are Canada, Denmark, the European Union, Iceland, Norway, Russia and the US.

NASCO assesses the status of wild salmon populations and develops policies to protect them.

WWF "strongly urges NASCO members to follow the advice of scientists and adopt all necessary measures to restore runs of wild Atlantic salmon".

Humans responsible

Over the last century, it says, salmon have disappeared from more than 75% of Baltic rivers, and catches in Scotland and Ireland today are roughly 25% of what they were in 1970.

WWF says human activities are to blame for all the problems besetting the species.

It singles out:

• dams and other river engineering works which block the fish from passage to suitable spawning grounds
• industrial, domestic and agricultural pollution
• salmon farming, which WWF says spreads diseases and parasites to wild populations. It says almost a million farmed salmon escape annually in Norway alone. Interbreeding between farmed and wild stocks is also a problem, and WWF says the possible introduction of genetically-modified salmon "could eventually wipe out wild stocks".