North-East Arctic Haddock Melanogrammus aeglefinus (Linne)

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North-East Arctic Haddock Melanogrammus
aeglefinus (Linne)
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Year-class abundance of haddock aged 3 (1) and
haddock annual catch (2) in 1947-1995
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Long-term fluctuations of the mean annual
temperature in the main stream of the Murman
Current along the Kola Section (St.3-7) in 0-200
m layer and the abundance of the Northeast Arctic
haddock aged 3 in 1950-1995
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Year-class distribution of the Northeast Arctic
haddock with different strength depending on sea
temperature in 1950-1995
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Abundance of year-classes aged 3(1) and haddock
spawning biomass (2) in 1950-1995
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Long-term variations of year-class abundance of
haddock aged 3 (1) and the spawning stock
(individuals aged 6-8) (2) in 1950-1995
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Strength of the year-classes aged 3 (1), as well
as the portion of individuals aged 3-5 (2) and
6-8 (3) in the spawning stock of haddock in
1963-1995
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Distribution of haddock year-classes with
different strength depending on the size of the
spawning stock of individuals aged 6-8 (thou.t)
in 1950-1995
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Year-class abundance of haddock aged 3 (1) and
total abundance of immature individuals aged 3
and older in the year of the appearance of
year-classes (2) in 1950-1995
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Distribution of haddock year-classes with
different strength depending on the density of
population in 1950-1995, in normal and warm years
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1.     Haddock is characterized by a very great
difference in abundance of some year-classes and,
as a result, by very abrupt year-to-year
variations of commercial and spawning stock
size.2.     In the most of cases, during the
first years of haddock year-class life, water
temperature was a reliable indicator of strength
at age 3. In anomalous cold years, all the
generations of haddock were very poor despite the
level of spawning stock, density of population
and other factors. In the normal and warm years,
the effect of water temperature on haddock
juvenile survival and year-class abundance
becomes weaker.3.     Haddock year-class
abundance, to a great extent, depends on the
spawning stock size and structure. The
individuals aged 6-8 spawning two and more times
have the maximal influence on strength of haddock
year-classes.4.     The immature stock
abundance of haddock distributed in the Barents
Sea also has an impact on the strength of the
year-classes. The relationship of the year-class
strength and the density of population is
especially noticeable in the warm years, when the
role of abiotic conditions was high.
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Haddock spawning stock dynamics and deviations in
the stock size as compared to the previous year
level
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Haddock commercial stock dynamics and deviations
in the stock size as compared to the previous
year level