Map showing the locations that have been video recorded and sampled (green dots) and the locations that have only bee video recorded (orange dots).
Photo: MAREANO
The area on the shelf is characterized by sand and mud in different mixtures, with small areas of stone and gravel accumulations. The seabed is relatively flat, except from ploughmarks after icebergs (made when the ice retreated around 15 000 years ago). ”Pockmarks” (marks after seepage of gas or pore water from further down in the sea bottom) and coral reefs are local structures that also can be seen on the multibeam maps.
We investigated both coral reefs and pockmarks with the video rig Chimaera at depths around 350 m. At one location we were lucky and landed right in a pockmark with thick carbonate crust. Here we also observed dense stands with siboglinid polychaets, a group of animals where several species are known to have symbiosis with bacteria feeding on methane and other chemical components leaking from the seabed.
A pockmark with thick carbonate crust.
Photo: MAREANO/IMRMore than five new coral reefs have been detected during the cruise so far. These are elatively small (< 50 m in diameter) but seem to be in relatively good shape, not impacted by bottom trawling or other human impacts, such as those related to the petroleum industry.
The ivory-white Lophelia-coral and Sebastes. The red variety of Lophelia is hardly visible in the lower picture together with brown dead skeletons of Lophelia.
Photo: MAREANO/IMR
