The Davis Strait - DCE - Nationalt Center for Miljø og Energi

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In general, abundance of C. finmarchicus increases as you move from the Arctic
region and further south to the sub-Arctic. This is because the drift of C.
finmarchicus into the assessment area by means of the West Greenland current
has strong implications for their distribution, life cycle and production,
and for the succeeding link in higher trophic transfer, e.g. Atlantic cod (Gadus
morhua). Transportation of C. finmarchicus from the North Atlantic into
the South and West Greenland waters can, depending on food availability,
outnumber the true Arctic C. glacialis and C. hyperboreus by a factor of three
throughout the year (Pedersen et al. 2005, and references therein). C. glacialis
and C. hyperboreus have a higher fat content.
There is a lack of knowledge of zooplankton from the offshore parts. It is assumed
that the zooplankton community in the assessment area is similar to
that found in the coastal area in Southwest Greenland; however, there is expected
to be a difference in biomass with lower density offshore than inshore/coastal
areas, e.g. the Fyllas Banke area.
4.2.4 Zooplankton dynamics in the coastal areas
High occurrence of zooplankton species linked to the fishery banks, e.g.
Fyllas Banke, are controlled by the hydrographic characteristics of the area
and associated predator-prey interactions (Pedersen & Smidt 2000, Pedersen
& Rice 2002, Pedersen et al. 2002, Ribergaard et al. 2004, Buch et al. 2005,
Pedersen et al. 2005, Bergstrøm & Vilhjalmarsson 2007, Arendt et al. 2010,
Laidre et al. 2010). The frontal system occurring at the banks and the
upwelling of deeper nutrient rich waters enhances the productivity of the
plankton communities in those areas.
A model simulation by Pedersen et al. (2005) describing the linkages of hydrographical
processes and plankton distribution demonstrated across the
fishery banks (64-67º N) of the Southwest coast of Greenland that wind
fields and tidal currents were important, creating temporally retention areas
of the plankton. High copepod abundances, mainly Calanus spp. coincide
with high chl a values just east and west of the banks. This agrees with model
description of upwelling, which occurs mainly west and to a lesser extent
east of the banks, increasing the plankton productivity in the bank areas.
Munk et al. (2003) found a close link of plankton distribution with hydrographical
fronts, and apparently specific plankton communities were established
in different areas of the important fishery banks of West Greenland.
Ichthyo- (fish) and zooplankton communities differed in species composition
in the north-south distribution of polar versus temperate origin. It
seems that flow of major currents and establishment of hydrographical
fronts are of primary importance to the structure of plankton communities
in the West Greenland shelf area, influencing plankton assemblage and the
early life of fish.
4.2.5 Higher trophic levels – large zooplankton and fish larvae
Large zooplankton species such as the krill species (Meganyctiphanes norvegica)
were examined in September 2005 by the Greenland Institute of Natural
Resources (GINR) (Bergstrøm & Vilhjalmarsson 2007) as well as in association
with large baleen whales in West Greenland (Laidre et al. 2010). Krill
were found in scattered aggregations in most of the area (Fig. 4.2.2).