ALBERT

Description: At opposite ends of our world lie the poles. In the North, the Arctic, an ocean surrounded by coasts; in the South, the Antarctic continent surrounded by an ocean that separates it from the nearest landmasses. At first glance, the poles could not be more dissimilar owing to their contrasting location, geography, and tectonic and evolutionary history. The amplitude and types of ice cover, though differing between the poles, are influenced by the same climatic, atmospheric, and hydrodynamic processes that affect the entire Earth. Freshwater influx into their coastal areas too—beyond the effects of glaciological changes and dynamics such as glacier melt and increasing meltwater discharges—is different: in contrast to the Arctic, the Antarctic continent and sub-Antarctic islands lack major rivers. However, their latitudinal range and low temperatures, ice shelves, icebergs, sea ice, impacts from tidewater and land-based glaciers, significant seasonal variation in light intensity and, hence, primary productivity, offer parallel environments for organisms that have adapted to such conditions. Although we know much about the similarities and differences from an environmental perspective, there are still many unknowns about how benthic communities, especially the meiobenthos, from both regions compare. In this chapter, we provide an overview of the contrasts and parallels between Arctic and Antarctic meiobenthos and place it into context of their extreme habitats. Following a brief account of Arctic and Antarctic evolution and the historical study of their faunas, we (i) compare how extreme polar conditions affect meiofauna across four main habitats: polar coastal areas and fjords, continental shelves and ice shelves, the deep sea, and sea ice, and we (ii) discuss the implications of climate change on meiofauna in these habitats. Reflecting on (i) and (ii) allowed us to identify frontiers for future research of polar meiofauna, which we put forward in the concluding sections of this chapter.