The effect of a sharp pycnocline on plankton dynamics in a freshwater influenced Norwegian fjord

Temporal variability in abundance and biomass of ciliates and copepods in the eutrophicated part of Kaštela Bay (Middle Adriatic Sea)

“…As to the impact of abiotic factors on the temporal variability of the investigated zooplankton groups, our results suggest that salinity may be more important than temperature (Tables 2, 3); this is also supported by Andersen and Nielsen (2002). However, a correlation does not automatically implicate a direct causal relationship, and the trophic relationships between microzooplankton groups and biotic parameters are rather complex (Fig.…”

Feeding opportunities of larval and juvenile cod (Gadus morhua) in a Greenlandic fjord: temporal and spatial linkages between cod and their preferred prey

“…Cladocerans which at times accounted for most of the available prey were not found in the outer fjord before the ice break-up of Kapisigdlit River around June 20. An aggregation near the surface layer (Onbe and Ikeda 1995;Andersen and Nielsen 2002) and an ability to cross a strong halocline (Pagano et al 1993) might have positioned them in the top layer where there was an outward moving current (Swalethorp unpubl.). Despite being advected, fast reproduction allowed them to maintain a high biomass at St. 6, as observed in a Norwegian fjord .…”

“…Marine cladocerans tend to aggregate close to the surface (Onbe and Ikeda 1995;Saito and Hattori 2000;Andersen and Nielsen 2002) or in association with subsurface blooms (Nielsen 1991). They rely on early maturation and parthenogenesis, producing large offspring to overcome predation, instead of good escape capabilities (Lynch 1980;Verity and Smetacek 1996).…”

Turbulence and feeding behaviour affect the vertical distributions of Oithona similis and Microsetella norwegica

“…Indeed, O. similis copepodites seem to prefer the low salinity surface layer and we can conclude that salinity was not a barrier. Further, the salinity of this surface layer (29 to 32 psu) is well within the range of tolerance for these species (Andersen & Nielsen 2002). …”

“…The aim of the present study is to analyze the vertical distribution of copepods, in particular the small cyclopoid Oithona similis and the small harpacticoid Microsetella norwegica, observed in the Skagerrak during 2 periods (spring 1999 and summer 2000) (Maar et al 2002(Maar et al , 2004 and in the North Sea (autumn 1998) ) in relation to different physiochemical factors. Very few studies have addressed the vertical distribution of these small non-calanoid copepod species (Lagadeuc et al 1997, Andersen & Nielsen 2002 and their role in the pelagic food web (Nielsen & Sabatini 1996, Green & Dagg 1997) even though they are highly abundant in most areas (Turner 2004). We hypothesize that the influence of turbulence on their vertical distribution in the water column should vary according to their feeding strategies.…”