The polar oceans are very different from other oceanic habitats in many ways, though existence of ice in these polar oceans imposes major habitat distinction. Sea ice affects the polar microorganisms by limiting on the penetration of light into the upper ocean and by providing inimitable ocean surface environment The sea ice provides a support medium for a variety and dynamic assemblage of microorganisms like prokaryotes and phytoplankton, which are frequently referred to as sea ice microorganism community (SIMCO). The physical environmentThe brine exclusion throughout the process of sea ice formation, together with melting in the summer season, contributes to persistent and major stratification of the water column (Hodges et al., 2005). This particularly the situation with Arctic Ocean where the undying sea ice cover confined wind mixing, while the geographical nature of the basins (land locked) constrains exchange with lower latitudes waters (Hodges et al., 1996) Other features of polar oceans, such as extreme seasonal variation in primary production and carbon fluctuation and low temperature, are frequently more intense compared to other oceanic environment. The unique and major differences between the existing polar oceans are due to the fact that, Arctic Ocean has a land locked geographical basin which receives approximately 10% of the total global run off of fresh water(Junge et al.,2002). While the other polar ocean called Southern Ocean surrounds a land mass enclosed by sea ice and alienated from lower latitudes waters by a definite circumpolar frontage. The rivers supplying water to the Arctic Ocean exhaust lower latitude terrestrial habitats, including boreal forests and tundra. These rivers are therefore extensive significant sources of the Arctic Ocean organic carbon. The southern Ocean gets no such terrestrial subsidy of carbon (Massana et al., 1998). Limited areas of indefatigably open water offer environments that differ from those areas that are under sea ice cover throughout the major part of the year. These open water regions as referred to as polynyas, which occur as a result of a diversity of physical processes. A number of studies carried out have shown that microorganisms within the polynya are livelier, active, and vigorous compared to their counterparts underneath the adjacent ice cover habitat. However, there is no or little overlap existing between the phytoplankton species found in the polynyas and adjacent sea-ice and the … [Read more...]
