Research summary 2007-2010
Research in this area has had the best possible start with the discovery of deep-sea hydrothermal vents in the Arctic; a vent system hosting a unique and basically unexplored fauna. The discovery and sampling of these new arctic vent fields provide unique data to further understand the migration of vent organisms and interactions between different deep-sea chemosynthetic environments.
Main content
Research in this theme involves the exploration of fauna associated with reduced habitats in the deep sea in the Arctic and NE Atlantic and aims to:
- determine the macrofaunal community diversity associated with hydrothermal vents and seeps including symbiotic microbe-metazoan relationships;
- compare the macrofauna with the fauna of other vent areas with a phylogeographic approach using molecular markers;
- map recruitment and dynamics of the biotas;
- determine the community ecological structure of the vent regions;
- find links to, and interactions with the neighbouring deep biosphere (e.g the microbial vent fauna), the secondarily sun-driven ecosystem (e.g. the deep sea) and the primarily sun-driven ecosystem (e.g. the photic zone);
- study the physiological adaptations of selected organisms.
We began by focusing on exploring the newly discovered vent systems on the Arctic Mid-Ocean ridges as well as exploring some cold seeps areas at the continental margins.
There has been international interest about the nature of an Arctic vent fauna. Our studies of the Jan Mayen vent fields in relatively shallow waters have shown that the fauna there is mainly composed of shallow- and bathyal species from the surrounding waters with only a few examples of species adapted to reduced habitats.
The discovery and exploration of the Arctic deep-water black smoker vent field in 2008 draws a completely different picture of an Arctic vent fauna. Our data show that the fauna composition is a result of high degree of local specialization and endemism. There are some similarities to the fauna of cold seeps along the Norwegian margin and to wood-falls in the abyssal Norwegian Sea. In addition, there are very clear indications that there has been a migration of vent fauna into the Arctic Ocean from the Pacific Ocean rather than from the known vent sites further south in the Atlantic Ocean.
All major fauna elements (including polychaetes, gastropods, amphipods and fish) seem to be specially adapted to these extreme conditions and most of them harbour symbiotic microorganisms.
Natural laboratories have been established to investigate the possible role of whale- and wood falls in the migration and distribution of fauna adapted to reduced habitats. In addition, settling plates and wood-falls have been placed within the vent systems to investigate recruitment in these systems.
Our team, together with our national and international cooperation partners, has a thorough knowledge of the deep-sea fauna of the Nordic Seas and the Arctic. This enables us to distinguish between specialized and background fauna and to provide information that can help track specialization and local speciation pathways. We thus have been able to propose that the AMOR is a new zoogeographical province for vent fauna. In addition, our data suggest that the Arctic vent fauna is more closely related to Pacific vent fauna than to its Atlantic counterparts.
We have successfully adapted and applied molecular methods (DHPLC) to the sample material. The results are providing new insights into the trophic interactions in a vent system. We are also combining these data with more classical analyses of stable isotopes. EST libraries for some reduced habitat fauna are currently being produced in collaboration with Auburn University, US.
