The Marine Biodiversity in the Polar Regions:
The present day biodiversity of the Southern Ocean marine faunas is the result of the geologic evolution of the continents, the subsequent change of the hydrography and paleoseaways, the global climate change, faunal extinctions, dispersal capabilities, physiological adaptations, and the zoogeography and evolution of the taxa which result from this geological framework.
In very general terms, the biodiversity is slightly lower in the younger Arctic compared to the more ancient Antarctic, however, not as low as it had been postulated earlier. Due to the isolation of the Antarctic shelf fauna, the endemism of many taxa are very high in the Antarctic, more than 90% for example for fish, Amphipoda and Cumacea. In the Arctic Ocean, the shelves are not isolated, but the deep-sea basins are.
However, until now there were only very few biological investigations done in the Arctic, therefore it is not possible to present percentages of Arctic deep-sea endemism until now.