Saturday 26th June 2010

Midsummers Day back home in Sweden. Here onboard the James Cook it is Curry Day (we get curry for dinner on Saturdays), and one week to go before we land in Vigo and have to go home and cook meals for ourselves once again.

Saturday's menu = curry night

After almost two days of no work due to the bad weather, everybody was eager to collect more samples and data. Luckily, the Atlantic Ocean calmed down sooner than expected, and we could retrieve the PAL lander and the Amphipod trap before lunch. Despite the sun shining outside, most people were working in the main lab until the next Isis dive began.

Debbie, Grant, Thom and Ben

After lunch the ROV was deployed for a 30 hour dive with eight benthic survey transects and one bioluminiscence transect on the schedule. Our photographer David Shale climbed up to a higher vantage point to film the launch of Isis on a sunny day.

David Shale with a birds eye view of the Isis launch

David Shale with a birds eye view of the Isis launch

During the benthic video transects we observe the larger animals living on the sea floor, for example sea stars, sea cucumbers, corals, anemones, and fish. However, on flat areas of  sea floor these animals can often be found living far apart from each other and it could lead you to believe that there is only very few inhabitants. What we cannot see on the video transect is all the smaller animals that live on the seafloor or in the soft mud. To study those we need different sampling equipment, and on this trip we use a megacorer. With a megacorer it is possible to do quantitative studies of the fauna. A core has a diameter of 10 cm so the volume of sediment can be measured, and the animals in there are identified and counted. Many of the smaller animals living on and in the sediment are worms, and I work on polychaetes, also called bristle worms. I examined a sediment sample from the upper 5 cm of a core and found, some small crustaceans, nematodes and 14 bristle worms belonging to 13 different species. Unfortunately these beautiful animals are very delicate and do not at all like the sampling-and-sieving procedure, so it’s rare to find a complete specimen.

Polychaete

Helena Wiklund

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