|Water Temperature:||0° to -2° C|
|Dates:||Pre-drilling visit 4 – 13 April 2007
Post-drilling visit 7 – 13 June 2007
|Gas & Oil Company||Total|
|SERPENT Representatives:||Dr Daniel Jones|
The Jack Bates was involved in its first of many SERPENT missions on the TOTAL E&P UK PLC Laggan drilling project, West of Shetland. This new development is very interesting to the SERPENT team as it expanded the West of Shetland work that we have already carried out into deeper waters (600m) in the Faroe-Shetland Channel.
SERPENT researcher Dan Jones took up residence on the Jack Bates in collaboration with TOTAL E&P UK PLC and in a two week mission studied the exciting marine life of this cold water area. A diverse seabed with many interesting animals was revealed by the high specification ROV on board the Jack Bates.
The Laggan field is situated on the southern bank of the Faroe-Shetland Channel. It is in a very interesting area where the warm Atlantic surface waters meet Arctic temperature (0 to -2 degrees C) deep waters from the Norwegian Sea. The depth of this boundary changes rapidly with time subjecting the animals of this area to large changes in temperature over very short time scales.
The seabed in this area has a diverse community of animals, there are completely different characteristic megafauna when compared to the shallower west of Shetland fields (Foinaven and Schiehallion visited in missions 1,2,3 and 4) but as a result of limited sampling in this area many of the species seen are very poorly known. The high quality photographs and samples collected greatly add to our understanding of the ecology of this area.
During several ROV dives we carried out detailed transect surveys to provide high resolution, quantitative information on faunal distribution, adundance and the biodiversity of the area. These video data will be extremely valuable in quantifying the communities of the west of Shetland slope, adding information to previous work that we have carried out. In these surveys we got an appreciation of the high biodiversity that exists in this environment of high pressure and rapidly changing temperature. We saw numbers of stripey Lycodes fish hiding behind large sponges and soft corals, hagfish buring their heads in the sediment, large (10cm diameter) pycnogonid sea spiders along with their much smaller relatives; there were huge numbers of small prawns and brittle stars, starfish and feather stars were frequently seen and occasional sightings were made of other rarer species including cuttlefish and rays.
With the suction sampler we were able to capture a selection of representative species from the area. The amphipods collected were immediately put to good use by our resident expert Tammy Horton , who quickly identified these specimens ( click here for more information on the amphipods ). The other specimens will be identified to species level which is not usually possible from a photograph alone and as coupled with good photographs, a more accurate idea of what these animals look like in situ can be obtained. Often the fauna of this area is only known from trawled samples and have never been seen in their natural environment before.
Launching the ROV
All the underwater images and sampling were carried out using the Clansman ROV operated by Subsea 7 . The ROV system on board the Jack Bates is one of the most advanced rig ROV systems in the world, an important requirement as the Jack Bates is one of Transoceans flagship deep water harsh environment rigs. The ROV is launched through a moonpool in the rig which allows direct access to the water below under often testing conditions.
Seabed sampling of a whelk
The ROV was equipped with a number of camera systems including a high quality zoom video, low light SIT cameras and a Kongsberg OE14-208 digital stills camera. These are all mounted on a pan and tilt unit on the front of the ROV, allowing them to be directed by the pilot. As well as this there were two dextrous manipulator arms, which were used in conjunction with a suction sampler to take specimens of the marine life around the rig. This proved very sucessful with a number of very good specimens being obtained and preserved for identification and future scientific use.
Many thanks to all on the Jack Bates and particularly to the ROV team (pictured below) whose skill and enthusiasm made everything possible. Thanks especially to TOTAL E&P UK PLC for making this visit possible, Transocean for hosting me on board the Jack Bates and Subsea 7 for providing the ROV support.