Publication Date:
2017-01-27
Description:
Euphausiid (krill) and amphipod dynamics were
studied during 2006–2011 by use of plankton nets in
Kongsfjorden (79�N) and adjacent waters, also including
limited sampling in Isfjorden (78�N) and Rijpfjorden
(80�N). The objectives of the study were to assess how
variations in physical characteristics across fjord systems
affect the distribution and abundance of euphausiids and
amphipods and the potential for these macrozooplankton
species to reproduce in these waters. The abundances of
euphausiids and amphipods were higher in Kongsfjorden
than in Rijpfjorden and Isfjorden, and the highest abundances
were observed at the innermost stations of Kongsfjorden,
where Thysanoessa inermis and Themisto libellula
dominated. The Atlantic species Thysanoessa longicaudata,
Meganyctiphanes norvegica and Themisto abyssorum
dominated at the outside Kongsfjorden. Inter-annual and
seasonal variability in abundances of euphausiids and
amphipods were evident. The presence of ripe euphausiids
outside Kongsfjorden indicates that they may reproduce in
these areas. Mature individuals of T. abyssorum were
recorded mainly outside Kongsfjorden, whereas no mature
or ripe T. libellula were present in both the inner and outer
parts of this fjord. If the warming trend persists, as seen
during the last decade, this would favour the Atlantic/boreal
euphausiid species, while Arctic species, such as the
amphipod T. libellula, may decline. Euphausiids and
amphipods are major food of capelin (Mallotus villosus) and
polar cod (Boreogadus saida), respectively, in this region,
and changes in prey abundance will likely have an impact on
the feeding dynamics of these important fish species.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
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