|The 'Scotia Seep' Pirates offshore on board the Marine Scotland Science |
Vessel M/V Scotia in July 2015
|Frozen core packed in dry ice |
waiting for transport to BGS
The surrounding seabed habitats include areas of burrowing animals and anemones in churned-up soft sediment, sponge aggregations on soft sediment and cold-water corals. Several chemosynthetic bivalves (those that feed on chemicals from the sea water) were also recovered and are being identified by collaborators at the National Museum of Wales.
Six megacore samples were recovered from the seep and were frozen offshore to preserve unusual layering observed within the sediment and overlying water. One of those cores was packed in dry ice and transported to BGS for analysis including scanning electron microscopy (SEM) and geochemical analyses. Some of these analyses have already yielded some interesting results including a marked increase in concentration of base and heavy metals in particular copper, nickel, cobalt, arsenic and perhaps most interestingly uranium within sediments immediately below the sediment/water interface.
These analyses thus far indicate that upwelling, sulphurous and methane-rich fluids are being expelled at seabed on the western flank of Rockall Bank which supports a chemosynthetic community. This cold-seep is the first documented within the UK deep sea and the combination of unusual geochemistry and species suggests that it is quite different from the other cold-seep ecosystems in the north-east Atlantic such as those offshore Norway and Spain.
The exciting and unique results from this cruise are currently being written up for publication.
The Offshore Science Party
Francis Neat (Marine Scotland Science (MSS)) led the offshore expedition to find the elusive seep with Alan Jamieson (Oceanlab), Heather Stewart (BGS), Jim Drewery (MSS), Neil Collie (MSS), Mike Stewart (MSS), Mike Robertson (MSS), Graham Oliver (National Museum of Wales), Dave Hughes (Scottish Association for Marine Science (SAMS)), Amy Scott-Murray (Oceanlab), Thom Linley (Oceanlab) and Chris Welch (SAMS).
Geological interpretation has been undertaken by Thomas Barlow, Aurelie Devez, Lorraine Field, Andrew Marriott, Antony Milodowski and Heather Stewart at the British Geological Survey.
Biological interpretation has been undertaken by Jim Drewery (MSS), Brodie Fischbacher (Oceanlab), Martin Foley (SAMS), Dave Hughes (SAMS), Alan Jamieson (Oceanlab), Bhavani Narayanaswamy (SAMS), Francis Neat (MSS), Graham Oliver (National Museum of Wales), and Matthew Snape (SAMS).
Thanks to the officers and crew of the MRV Scotia. Offshore data acquisition was supported by the Marine Alliance for Technology Scotland Deep-Sea Forum.