The last five days have been very frustrating on the James Cook. Due to problems associated with the winches, the Chief Engineer said the winches could not be used until checked by qualified engineers. There followed a lot of e mail traffic between the ship, NOC and the winch company in Norway and the latter agreed to send out a team to fix the winches. As a result we left our stations over the Whittard Canyon and sailed towards Cobh to pick up the winch engineers. Because the ship is limited to 54 persons maximum two people had to get off so we could accommodate the engineers at sea.
After picking them up we sailed for 20 hours out into deep water so the wires on the winches could be tested down to 4000m. As there was nothing for scientists to do we caught up on e mails and worked on papers, although Sven and Nathan continued with their experiments measuring the respiration rate of deep-sea amphipods under pressure. The work on the winches took ~36h and they seemed to be working as they should although the engineers made a number of fine adjustments.
At the end of the tests we sailed back to Cobh by which time the wind had increased to force 7 and 8 and there was a reasonably large swell running behind the ship so we ‘surfed’ on the way back to Cobh. For the first time on the cruise we also had a number of birds following us. They were mainly gannets in their first and second year with some just attaining the adult plumage. Most of the full adults were most likely breeding chicks on gannetries along the remoter parts of the UK coastline. There were few fulmars, easily recognised by their stiff-winger flight and their skimming over the waves with their fat bellies almost touching the sea surface. One had to look hard but behind the ship in its wake were the small almost black storm petrels fluttering over the sea surface picking up small morsels of plankton. To round off last night a magnificent double rainbow developed to the southwest of the most intense hues. We arrived in Cobh this morning, dropped off the engineers, picked up our two colleagues and are now steaming southwestwards back to our canyon sites. There is a gentle swell and the ship has a mesmeric rocking motion…
Big, colourful animals, such as sea cucumbers and anemones, get people excited when they watch pictures of the seafloor in the ROV van. But there are lots of smaller animals lurking in the mud, and these are rarely visible in the ROV images. The ones I’m interested are called foraminifera. Like an amoeba, they consist of a single cell, and so are not animals at all but protozoans. Despite being single-celled, foraminifera often build an elaborate shell, or ‘test’, made out of secreted calcium carbonate (calcite) or of particles that they have picked up off the sea floor. This is an amazing thing for a single cell to do. Most protozoans are microscopic in size, but foraminifera can be pretty big - some species grow to several centimetres or more in size.
Big animals can be picked up off the seafloor by the ROV, but to find the creatures living in the mud, you have to first collect some mud and then sieve it (often getting very muddy in the process). We can get mud in push cores taken by the ROV, but during this cruise we discovered a better way. When the ROV samples large animals it often dumps mud into the ‘BIOBOX’, along with the animals themselves. Rather than throw this away, we tried sieving it. This BIOBOX mud has produced some of the best and largest Foraminifera collected so far during this cruise.
Here is a selection of species from the Whittard canyon. Some have tests made of calcium carbonate, others have tests made of particles from the seafloor. See if you can spot the difference.
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