The Arctic Ocean is a semi-enclosed basin that extends over 13.1 million km2. It is shallow relative to other oceans (average depth of 1296 m and maximum depth of 5220 m) with extensive areas of continental shelf that contribute 20% of the world’s total shelf area. It is strongly influenced by the huge quantities of freshwater and associated materials discharged by large arctic rivers, and has the lowest salinity of all oceans.
Bathymetry of the Arctic Ocean showing the large proportion (86%) of area that is composed of shelf and slope environments (red, yellow and green). (From this
website).
Sampling sea ice in the Arctic Ocean. (From this website).
Arctic seas contain diverse habitats for microbial growth including different types of sea ice, different water masses and sediments. Certain parts of the Arctic remain free of ice through much of the year, for example flaw lead polynyas and the North Water polynya. Certain parts of the shelf during winter accumulate barriers of ice called stamukhi, and these can retain the inflowing freshwater from large arctic rivers to form “stamukhi lakes”. Our understanding of the microbial diversity of this region is developing rapidly with the application of molecular techniques.
