The salmon hatchery which acts as a
maternity ward for one of England’s best fishing
rivers is readying itself for the busiest time of
the year.
In the coming weeks the next generation of
salmon to populate the River Tyne will be born
and nurtured at Kielder Salmon Centre before
being released into the waters which were home
to their ancestors.
Environment Agency
fisheries officers have spent recent weeks
gathering the prospective parents from three
main tributaries of the Tyne – the North Tyne,
South Tyne and the Rede.
By the end of November, about 125 adult
females and 130 males had been collected and
have been cared for in separate tanks at the
hatchery until the females became ready to spawn
this December.
Each mature female can produce between 6,000
and 14,000 eggs and the fish are checked weekly.
Once ready to release their eggs, the females
are anaesthetised and their eggs stripped
(harvested), ready to be artificially
fertilised.
The males’ milt (sperm) is then collected and
added to the eggs, which are fertilised within
30 seconds.
The fertilised eggs are incubated until
March, when 97 per cent will start to hatch.
At this stage in their lives, the fish would
be in the gravel of the river bed so Kielder has
an artificial river bed, using plastic instead
of gravel, to recreate a realistic habitat for
the alevins (baby fish).
Five or six weeks later, the young fish
absorb the yolk sac attached to them and a
fortnight later emerge from the artificial river
bed as fry.
Environment Agency fisheries staff will have
been keeping a watchful eye on the young fish
and at this stage have to start feeding them
throughout daylight hours, from about 4am until
10pm, with an organic dry fish food high in
protein and essential oils, vitamins and
minerals.
“This process happens every year and plays a
vital role in replacing salmon that have been
lost as a result of Kielder Reservoir blocking
access to breeding grounds,” said hatchery
manager Richard Bond.
“As the young fish mature the work becomes
very labour-intensive but the outcome is very
satisfying.”
By mid-summer, the salmon are classed as parr,
at which stage they can start to be returned to
the tributaries from where their parents
originated.
The following spring about a third of the
young salmon, now called smolts, will embark on
a marathon journey into the North Atlantic, with
the remainder setting out 12 months later.
The 5in-long fish set out for the feeding
grounds off the Faroes, Iceland and Greenland
and in a year will have increased their weight a
hundredfold, from 20 grams to two kilograms.
