ANGLERS and fishermen on the River Tweed and its tributaries are being urged to be vigilent after a pink salmon was netted at Paxton earlier this month.
It is believed to be the third time that a pink salmon has been caught on the Tweed, and the River Tweed Commission has expressed concern at the recent capture, stating it would be ‘highly undesirable’ if the pink salmon bred with Tweed fish.
The male salmon was netted at Paxton on August 2 and is believed to have come from a northern Norwegian 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.
Nick Yonge, clerk to the River Tweed Commission and director of the Tweed Foundation, told the Advertiser: “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 on Friday, which had been caught at Amble.
“It looks like there a quite a few knocking around, but their natural distribution is in the north Paciifc, but they were brought into Russia for aquaculture and there is now an established population in parts of Norway, I’m led to believe.”
Mr Yonge said that it was likely that the fish caught at Paxton and at Amble had made their way from Norway thanks to the current.
Mr Yonge 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.”
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 their heavily spotted tail, characteristic of Pacific salmonids, should immediately show them to be something very different from native fish.
Females will also be pinkish-brown on the flanks, compared to the silver-flanked males.
The fish 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.
They are very uniform in size, reaching only 40 to 60cms in length.
Pink salmon were introduced to some Russian rivers around the White Sea in the 1960s and have since spread westwards and have now colonised some northern Norwegian rivers.
There is also an introduced population in Newfoundland, Canada, from which some rivers in Nova Scotia and Quebec have been colonised.
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.”
If anyone sees what looks like spawning activity by pink salmon in the Tweed they 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.