An investigation of cyanobacterial microflora in the northern, deglaciated part of James Ross Island in the NW part of the Weddell Sea, Antarctica , was conducted during the Antarctic summer season 2005-2006. Five main types of habitats with dominant cyanobacterial assemblages were analyzed (soils, seepages, streams, wetted rocky walls and lakes), and main ecological variables were measured (pH, temperature, intensity of global radiation, conductivity and nutrients), as a background for further ecological and ecophysiological studies. The definable traditional cyanobacterial morphospecies were identified.
The relationships between epiphytic fauna and habitat conditions were studied in three oxbow lakes of Wieprz River (eastern Poland). Fauna associated with macrophytes showed low species richness (range 8–11 taxa dependently on site and season) usually observed in lakes of high water trophy. Densities of fauna were high (mean 71–5250 ind. 100 g DW-1), typical for shallow lakes with well developed submerged vegetation. In the domination structure prevailed Gastropoda (relative abundance 23–100%) and Chironomidae (relative abundance 8–87%). Re-dundancy analysis showed the significance of four environmental variables – temperature, dis-solved oxygen, Ptot and P-PO4 as determinants of abundance of epiphytic fauna.
Hornsund and Kongsfjorden are two similar-sized Arctic fjords on the West coast of Spitsbergen. They are influenced by cold coastal Arctic water (Hornsund) and warmer Atlantic water (Kongsfjorden). Environmental conditions affect the timing, quantity, spatial distribution (horizontal and vertical) of spring and summer blooms of protists as well as the taxonomic composition of those assemblages. Here, we compile published data and unpublished own measurement from the past two decades to compare the environmental factors and primary production in two fjord systems. Kongsfjorden is characterized by a deeper euphotic zone, higher biomass and greater proportion of autotrophic species. Hornsund seems to obtain more nutrients due to the extensive seabird colonies and exhibits higher turbidity compared to Kongsfjorden. The annual primary production in the analysed fjords ranges from 48 g C m-2 y-1 in Kongsfjorden to 216 g C m-2 y-1 in Hornsund, with a dominant component of microplankton (90%) followed by macrophytes and microphytobenthos.