23 September – 9 October 2008
14 – 19 October 2008
|Gas & Oil Company||Statoil|
|SERPENT Representative:||Dr. Andrew Gates|
This mission was the latest SERPENT visit to the Transocean Leader. Since the project’s inception in 2002 we have made 5 visits to the rig. The Transocean Leader is a semi submersible drilling rig capable of operating in harsh environments.
Graph showing the cumulative frequency of the sea-urchin Echinus acutus observations with increasing distance along a post-drilling video transect at a previous North Sea study site. The graph also shows the concentration of Barium in the sediment (g per kg) at four locations along the transect. This works shows low animal abundance where barium concentration is high.
The core samples and video transects taken at Haklang are represented in the diagram below. Sediment samples were collected from 6 sites at increasing distance from the BOP with replication at each site. The video transects were taken at nine headings radiating from the BOP.
Diagram showing the location of video transects and push core samples taken during the Haklang mission. The central black dot is the main drilling site.
The push cores were collected using the precise manipulation capabilities of the mechanical manipulator arms.
The fauna at Haklang was very similar to that at Midnattsol and some of the other Norwegian deep water sites SERPENT has worked at. For this reason more time was spent on sample collection than image and video collection. For a comprehensive gallery of images of animals from the Norwegian deep-sea have a look at the Norway Gallery
The most abundant species to be observed at Haklang was a type of cerianthid anemone. These are burrowing organisms so they were able to move up through the sediment, even in areas which had been heavily impacted by drill cuttings.
A cerianthid anemone and a pycnogonid, or sea spider, on the drill cuttings close to the well at Haklang
Other notable observations were the cirrate octopus that are often seen on SERPENT visits to this area and the rays which seem ubiquitous in the deep waters off Norway.
Rays are one of the most common fish found in the deep waters off Norway.