Understanding the impacts of global climate change on marine organisms is essential in a warming world in order to predict the future development and functioning of the benthic ecosystem. The Arctic is impacted by warming surface waters and a shrinking sea-ice cover, both influencing primary productivity and subsequent organic matter export to the deep ocean. Furthermore, benthic bacteria that mainly depend on organic matter supply from the surface ocean and that play a major role in carbon cycling at the seafloor, will be affected by these changes. However, only little is known about spatial and temporal variations of microbial benthic communities in relation to climate change impacts on pelago-benthic coupling, due to the lack of benthic time-series studies in the Arctic. Therefore, the investigation of Arctic benthic microbial diversity patterns along spatial and water depth gradients and with interannual changes in surface ocean productivity were the major objectives of this thesis.