The Nature of Scotland – Autumn 2011 – Issue 13

Alien salmon species found in Tweed
Fishermen in the Borders have been urged to kill and report any pink salmon
found in the River Tweed or its tributaries.
Two males of the non-native species have been caught in the river recently.
This has prompted the Tweed Foundation to issue a plea to anglers to help stop
the spread of the pink salmon.
The fish – which is also known as the humpback salmon – is the smallest and
most abundant of the Pacific salmon family. There are fears that the alien species
could colonise the river and affect stocks of the Atlantic salmon for which the
River Tweed is world famous.
Nick Yonge, director of the Tweed Foundation, advised anyone landing a pink
salmon to kill it and report the sighting immediately. “They’re not a native species
and we simply don’t know what effect they could have. We don’t think they are
breeding, and indeed we don’t know if they could breed with Tweed fish, but
clearly we wouldn’t want them to.”
Pink salmon are a fish of the north Pacific, but were introduced to some
Russian rivers in the 1960s. They’ve since spread westwards and have now
colonised some northern Norwegian rivers.
There is also an introduced population in Newfoundland from which some
rivers in Nova Scotia and Quebec have been colonised. However, the most likely
source of the fish in the Tweed is northern Norway.
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.
Any angler who catches a pink salmon in the river is asked to kill it and report
the incident to the River Tweed Commission on 01896 848 294.
NEWS
www.snh.gov.uk 23