Dec 05 - South Georgia to Stanley
Starting with Science
The Continuous Plankton Recorder
with Sophie Fielding
On the trip back from King Edward Point the swath was turned back on for continued surveying of the seabed as described in a recent website, but also, soon after leaving Cumberland Bay, a new piece of kit for this cruise was deployed. This was the continuous plankton recorder (CPR), a device designed to collect near-surface plankton. In all, the CPR was towed behind the stern of the ship for a total of 800 miles of the trip back to Stanley.
The prototype of the CPR was first used for sampling krill in 1925 in Antarctica, and was then modified in the following years to be used to sample plankton. This modified version has been used as a permanent monitoring tool for plankton in the North Sea since 1946. Towed at a depth of about 10 metres it is robust enough to be used off the back of almost any vessel, at any speed and in any sea conditions. Water passes through the recorder depositing plankton onto a moving band of silk. The silk, once unwound in the laboratory, provides a picture of any changes in plankton in the water along the 800 miles we have travelled from South Georgia to Stanley – much like a roll of film.
The silk sample blocks are stored in formaldehyde, to be later analysed back in the UK. Initially, the “green-ness” of each block is assessed visually, giving an initial indication of any phytoplankton (microscopic plants) blooms along the transit period. A very small sub-sample (0.1%) of the block is then analysed under high-power microscopy, counting all phytoplankton present (phytoplankton field analysis) and a further, larger sub-sample (2%) of the block analysed under low power microscopy counting all the microscopic animals - zooplankton (zooplankton traverse analysis). Finally, all zooplankton present on the whole sample block bigger than about 2mm are counted and identified (zooplankton eye count analysis).
And on to Stanley
And with the CPR being towed off the stern of the James Clark Ross and the Swath still going we headed in a straight line back to the Falklands. The rough oceans and bad weather of the Western Core Box now behind us, we headed towards the end of a very pleasant, if hectic first trip into Antarctic waters for the season. Despite running slightly behind schedule due to a combination of weather and cargo work the mood was calm and relaxed for the end of cruise dinner on 29th November. After a wonderful meal of Uraguayan Steak, and speeches from the Captain, banning the use of the term 'Last' over the coming couple of months, (sorry!) and from Alex Tate, along with Sophie Fielding, part of the Pricipal Science Officer Double Act, we all retired to the Officers Bar.
All the journey back to the Falklands, one of the main questions had been as to whether we would cross paths with the sister ship of the James Clark Ross, the RRS Ernest Shackleton. Right down to the last minute, we were all unsure whether or not we would have the chance to catch up with old friends and also fly the Jolly Roger in recognition of the seniority of Captain Elliott. All was prepared for the meeting, with our scheduled arrival to refuel at Mare Harbour on 30th November at nigh on exactly the same time as the Shackleton was due to leave.
Flag preparations were put into disarray though when another of the James Clark Ross's counterparts came into view, slowly getting closer and closer. The HMS Endurance was still a distance away when we were subject to a fly-by by two of the Linx Helicopters they have on deck, so crucial to certain aspects of BAS operations. The flags out and prepared would obviously be slightly inappropriate for this encounter. The HMS Endurance was also due for Mare Harbour, making our courses almost identical and leading to a fairly close and, all in all, a pretty exciting encounter between the two ships.
The Ernest Shackleton though, was unfortunately slightly too late for the party. About an hour after the Endurance had started for our position, and once it had already dropped back from our stern, the 'Shack' came steaming past us on our port side. After passing us, and then the Endurance, by that time several miles away, she headed off into the distance in exactly the same direction as we had just come from.
The reason the the JCR and the Ernest Shackleton had headed to Mare Harbour rather than to FIPASS at Stanley was for fuel. This was to be taken from the large-bore hose attatched to a floating buoy outside Mare Harbour, as opposed to actually going into berth ourselves. It was to be done with the assistance of the tug The Indomitable. After the floating hose was connected to one of our cranes it was lifted on to the aft deck under the control of the the Bosun's Mate, Marc 'BINS' Blaby. This then allowed members of the Engineering team to connect the hoses and fill her up.
After 4 hours of filling up with fuel, the James Clark Ross headed away from Mare Harbour and on to Stanley, where she arrived in the very late hours of 1st December. Having patiently waited overnight she then headed in to berth after first light, ready for another heavy four days of cargo work, a major change over in the ship's compliment, a visit by local school children and an evening as hostess to the local community.