Anglers on the River Tweed have been warned that they should kill any pink salmon they catch, given the threat they pose to native species.
Recent reports from the Environment Agency have noted that a number of pink salmon have been spotted recently in nets along the east coast of England.
One of the alien species was caught by an angler fishing near Wylam on the Northumberland Tyne a couple of weeks ago.
Dr Ronald Campbell of the Tweed Foundation said this week: “It is currently the spawning season of the pink salmon.
“They will have come from north Norway where rivers have been colonised from nearby Russian rivers to which pink salmon have been introduced.”
In recent years, four pink salmon have been reported on the Tweed.
Two were caught in 2011. One fish was caught at the nets at Paxton,while the other was seen for sale in a Kelso fish shop having been caught at Amble on the Northumberland cost a few days previously.
Back in 2007 another two were spotted. One was seen at Boleside, and the other near Norham.
Adult pink salmon are actually steel blue fading to blue green alon the back, silver along the sides and white on the belly.
They have large black spots above the lateral line and on the dorsal, adipose and tail fins.
As the males grow they develop a ‘kype’, the large, hooked lower jaw, and the typical hooked snout. They also grow a large hunched back.
Much of the body takes on an overall pink hue, except the head and anterior ventral surface, which become a grey-green.
The shape of the growing female does not change too much, but she also becomes very pink with a grey head.
If Tweed anglers have any difficulty identifying your catch, then they are urged to contact the Tweed Foundation.
They can either phone on 01896 848271 or email: firstname.lastname@example.org