The Tweed Pacific Salmon - a new run possible?
Although it belongs to a Pacific Salmon species, this fish did not swim to Tweed from the other side of the world! In the 1960's this species was introduced to rivers flowing into the White Sea, in North-west Russia, and is now well established there – and may well have established some other populations in northern Norway. It was also introduced to Newfoundland in the 1950’s and has established there as well and strays are known from Labrador, Nova Scotia and Quebec. The Boleside fish will have come from one or other of these introduced populations.
The first Pink Salmon to be taken in Scottish waters was in July 1960, when one was netted off Aberdeen and there have been nine known captures since then, but only one on rod and line (caught on the Dumbartonshsire Leven in 2003). All the others were taken in nets other than one found moribund in the Naver in 1973. The Leven fish was the first known since 1973 so the Boleside fish is the second after this long gap.
They have also turned up elsewhere in the UK. One was caught on rod and line in the Derwent in 1960 and there may have been as many as three taken in the North East of England Drift nets in 2001. It may be that the reduction in drift netting will mean more might turn up in Tweed in future, an unexpected result of the buy-out!
Pink Salmon are the smallest of the Pacific species, usually 3 to 5lbs in weight. They differ from other salmonids in generally spawning close to tidal water and emigrating to the sea as Fry rather than living in freshwater for a year or more and then emigrating as smolts. Their spawning season is from mid-July to late October (the Boleside fish ran milt when captured). Almost all live for two years, leading to very distinct runs in alternate years in some places as the year-groups do not overlap and interbreed.