|Location:||Rosebank-Lochnagar, North East Atlantic, UK|
|Water Temperature:||No data|
|Dates:||Pre-drilling visit 4 – 13 April 2007
Post-drilling visit 7 – 13 June 2007
|Gas & Oil Company||Chevron|
|SERPENT Representatives:||Dr Andrew Gates|
SERPENT carried out a mission in collaboration with Chevron UK to study the ecology of the deepwater Faroe-Shetland Channel; in particular the effects of drilling disturbance. The mission took place on the semi-submersible drilling rig Transocean Rather in two parts; one pre-drilling and one post-drilling visit.
The pre-drilling visit was used to observe the environment prior to disturbance and to set up some experiments on the seabed. The follow-up visit was used to repeat the pre-drilling surveys and to recover the experiments.
During the pre-drilling visit the Subsea 7 Centurion 05 HD work class ROV was used to collect video transects centred on the proposed location of the BOP prior to drilling disturbance. These were repeated during the post-drilling visit in order to assess the disturbance caused by the drilling operations.
A number of experiments were also deployed during the first visit and recovered in the second. These included a protocol new to SERPENT to collect deep water biofilms to study the micro-organisms that grow on surfaces in the deep sea and bioturbation experiments to monitor the reworking of the disturbed sediment by the organisms living in the mud on the seabed.
Rays were the most common fish observed at Rosebank.
Nymponid pycnogonids (Sea spiders) were common at Rosebank. A number of different species were observed including the two above. The pycnogonid on the right is carrying juveniles.
Cephalopods: Two different species of octopus were present at Rosebank. Left: A benthic octopus resting on the seabed. Right: a pelagic cirrate octopus observed swimming during ROV transit.
A number of different Alcyonaceans (soft corals) were present attached to rocks on the seabed.
Porifera (Sponges): There were a number of different sponge species observed during the SERPENT visit. The unidentified sponge on the left was commonly attached to larger rocks while the giant clubsponge (Chondrocladia gigantea) (right) was the only specimen of an uncommon species observed during the visit