Over centuries the deep sea was considered as a vast, desert-like environment with low number of species. However, in recent years knowledge about biodiversity in the deep sea has started to increase and today we know that the deep ocean on planet Earth hosts an enormous diverse deep-seabed life. Biodiversity in the deep sea depends among other parameters on water depth, which in turn is linked to food availability. In contrast to the past assumption that deep-sea organisms live in very stable conditions, relying completely on primary production which takes place in the euphotic zone, it is nowadays clear that various biogeochemical and physical conditions and parameters that govern deep-water ecosystems are highly dynamic and variable both, in spatial and temporal scales. The diversity of the benthos is very likely linked to the complexity of the seafloor.

 

Since polar organisms are strongly adapted to extreme environmental conditions with strong seasonal forcing, the accelerating rate of recent climate change challenges the resilience of Arctic life. The entire system is likely to be severely affected by changing ice and water conditions, varying primary production and food availability to faunal communities, an increase in contaminants, and possibly increased UV irradiance. The stability of a number of arctic populations and ecosystems is probably not strong enough to withstand the sum of these factors which might lead to a collapse of subsystems.

 

To detect and track the impact of large-scale environmental changes in a the transition zone between the northern North Atlantic and the central Arctic Ocean, and to determine the factors controlling deep-sea biodiversity, the Alfred Wegener Institute established the LTER (Long-Term Ecological Research) site HAUSGARTEN, representing the first, and by now only open-ocean observatory in a polar region.