FISHERMEN in the Borders have been urged to kill and report any pink salmon found in the River Tweed or its tributaries, writes Adam Drummond.
It follows a pink male of the salmon family being netted at Paxton earlier this month – the first time for four years that the species has been spotted in the region’s waters.
The River Tweed Commission have since expressed concern at the find, stating it would be “highly undesirable” if pink salmon bred with Tweed fish.
Nick Yonge, clerk to the River Tweed Commission and director of the Tweed Foundation, said: “I don’t think they are breeding, and we don’t know if they could indeed breed, but clearly we wouldn’t want them to.
“If someone comes across one they should take it and not put it back in the river.”
Mr Yonge added that another pink salmon had been found at a local fishmongers in Kelso, which had been caught at Amble in Northumberland.
“It looks like there a quite a few knocking around.
“Their natural distribution is in the north Pacific, but they were brought into Russia for aquaculture and there is now an established population in parts of Norway, I’m led to believe,” he said.
Mr Yonge believes that it is likely that the fish caught at Paxton and at Amble had made their way from Norway thanks to the current.
And he urged anyone landing a pink salmon to kill it and report the capture to the River Tweed Commission.
He added: “It is a curiosity and it is not unprecedented, but it would be much better if they were taken out the river.”
In July 2007 another male was caught and killed by an angler at Boleside, near Galashiels and in the August of that year there was a report of another fish being caught and released at Norham, which was suspected to be a pink salmon.
Male pink salmon are particularly distinctive, as they develop a prominent hump in front of their dorsal fin, as well as pronounced curve of their jaw when sexually mature.
Breeding males are immediately identifiable because of their humps and will almost certainly be running ready to spawn at this time of year. Their black tongues and heavily spotted tails are also very obvious.
Females are less obviously distinctive, but have a heavily spotted tail.
Females will also be pinkish-brown on the flanks, compared to the silver-flanked males.
The fish, usually 40 to 60 cms long, are steel blue to blue-green on their backs with white on their bellies. The large black spots on their backs, upper flanks, fins and tail can be as large as the fish’s eyes.
A statement on the River Tweed News website, run by the commission and foundation, states: “Both the Boleside and Paxton males were running milt and there is the possibility of breeding occurring in the Tweed, which would be highly undesirable.
“The species does not seem to have any great difficulty in spreading its range as shown by the way it has colonised rivers in northern Norway and eastern Canada from the original, man-made, introductions made to those areas.
“Their spawning zones are in the lower part of main channels, even in tidal reaches or, occasionally, in tributaries well upstream.”
Anyone who sees what looks like spawning activity by pink salmon in the Tweed should inform the River Tweed Commission immediately.
Any angler who catches one should kill it and should also report it to the commission on 01896 848294.