Deep-sea biodiversity with the example of the Kurilian-Kamchatka moat:
The deep-sea is the largest habitat on earth, yet it is one of the least known regions. Despite the seemingly inhospitable conditions of temperatures of 1-2 °C, darkness, food poverty and high pressure, we often find rich communities in the deep-sea. Down to abyssal depths of approximately 3,500-4,000 m species numbers usually rise, however in deep-sea trenches they decrease.
It is assumed that the deep-sea trenches isolate species and prevent their biogeographic distribution (disperal) in surrounding abyssal regions. In order to study a hadal trench system, an expedition was performed to the Kuril Trench in the summer of this year (2016).
Initial results from on board the RV Sonne include, among others that at hadal stations down to a depth of 9,683 m very high abundances of various taxa can be found, such as in bivalves or echinoderms (sea cucumbers) and that many species show world records in their depth distributions such as, copepods, peracarids, ostracods, worms or molluscs.