Annual Moorings and Sediment Traps

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Fresh from our return to the UK we have been very busy cataloguing all of our samples and downloading all of our data from our probes, ready for data interpretation. While we are busy in the lab, analysing the many samples we collected, we would like to keep you all up to date with the other work that our colleagues were also up to on Lake Baikal.

Our EAWAG colleagues have been deploying moorings close to the Neutrino Base Camp for the past 10 years, working in close collaboration with Dr. Elena Vologina at the Institute of the Earth’s Crust, Russian Academy of Science. These moorings have numerous data loggers that continuously record the temperature and depth of the lake water at multiple depths down the water column. These data are of great interest to physicists who have been looking in detail at internal waves within the water column and the complex mixing of different water masses in the lake.

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Along the same moorings, Dr. Mike Sturm and Dr. Elena Vologina have been deploying sediment traps. These are both open (collecting sedimenting particles throughout the year) and sequencing (12 traps each opening on rotation, for 1 month).

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These are of great interest in order to understand any resuspension of sediments (in bottom waters) as well as aquatic productivity changes throughout the year and indeed between multiple years. This year, we have been lucky enough to share some of the trap material! 

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Sarah will be able to identify the different diatom species that are present, giving detailed ecological interpretations of water column conditions (e.g. nutrient availability, light etc). If we have enough material we may even be able to analyse the δ30Si composition of diatoms collected from the different months of the year and understand silicon utilisation changes by this algae, as the year progresses. This is essential in order to understand modern day dynamics of silicon utilisation and therefore permit down core reconstructions of productivity changes. More to come on our success later this year…

However, for now, the three moorings are back in place for the following sampling year. So a successful trip for our colleagues and here’s to many more such years of data and sampling on Lake Baikal.

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Farewell Lake Baikal…

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Yesterday Ginnie and I spent our last morning on Lake Baikal. We successfully completed all the laboratory work, spending hours in the lab kunk filtering in total a combined amount of 90 L over the last few days. The morning was spent finishing off all the packing, and thoroughly tidying both the lab kunk and our cabin for the next occupants. Once the van had been strategically loaded with all our equipment and samples we took part in our last Pososhok with our Russian and Swiss colleagues. This is a traditional Russian farewell which entails a shot of vodka (or two) with a serving of cheese and salami with bread. We had the opportunity to give a toast to our colleagues who had accompanied us on our two week stay. Without their hospitality and assistance our fieldwork would not have been as successful. Thank you one and all!

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DSC02797As we were ready to leave, we watched the lab kunk being towed away by a tank to be relocated to the Neutrino site, 4.5 km away. This was our first water sampling & coring site, and where we set-up our nutrient enrichment experiment.

The journey across the lake ice back to the mainland was just as spectacular as the initial journey out there, and along the way our driver stopped to help a stranded van DSC02801on the ice. On the way to Irkutsk hotel we stopped to taste Omul (which is a distant relative of Salmon), which is endemic to Lake Baikal.

As soon as we arrived at the Irkutsk hotel, we were delighted with the prospect of indulging in some basic luxuries (i.e. warm showers…and no longer having to make the treacherous walk to the dreaded long-drop!!). We scrubbed up out of our fieldwork clothes and went bowling for the evening. All in all, it was a jam-packed day of packing and travelling, and we were looking forward to a well deserved night’s rest in a comfy bed. Needless to say though, we were sad to say goodbye to the incredible views of Lake Baikal.

Ice Skating on Lake Baikal

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Walking the 1 km home over the ice, after dinner, to our kunks we bumped into Rashid. He was just loading his ice skates into the back of one of the vans and wanted to know if anyone wanted to join him for a sunset ice skate on the lake. This was naturally a tough call to make as we had at least another 10 L of lake water back in the lab kunk that needed filtering that night.

DSC02781However, when he mentioned it would only be for 30 minutes or so, until the sun had set, we could not refuse! In we jumped and drove up the coastline for 10 minutes until we reached a patch of ice where the wind had blown away all of the snow. Clear ice was all that could be seen. We parked up, argued over the pair of ice skates that would fit our feet best and hit the ice. It was breathtaking! It was fascinating to see all of the ice fractures under our feet in the sunset and feel the undulations of it as we glided over. Even the ice cracking sounds, that we are now quite accustomed to, did not impede our enjoyment.

Thanks Rashid. An amazing 30 minutes, never to be forgotten.

Experiment – Day 7

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The time has come to collect our mesocoms which have been left suspended under the ice, in a water depth of 3 m in Lake Baikal. After a bout of continuous heavy snowfall on Saturday we decided to make our way to Neutrino to clear some of the snow cover, and ensure the diatoms would have enough light inorder to make the experiment a success. This turned out to be fortuitous as the snow cover was very deep, and therefore took us some time to clear the area.

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Our Russian colleagues even suggested that we break up the ice as this would make it easier in 3 days time to collect the bags again. After an hour of hard work, we had a clear ice hole to check that all our bags were still suspended from the ice and with a few tweaks (hanging the rope over a wooden frame) we were all set to leave them again, knowing that we would (hopefully) have an easier job to remove them on Wednesday.

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Wednesday soon came around. Luckily the weather today was much warmer than the day before, which had reached c. -30oC overnight. This was good news as we would be collecting the bags and we did not want them to freeze before we were able to transport them back to the lab kunk at Base Camp.

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After succesfully retrieving all 15 sample bags, we headed back to camp to begin our filtering procedures. This entailed a very long evening, operating the filtration units. Through our observations, the nutrient enriched mesocosm water samples took considerably longer to filter. This is as expected, and should imply the experiments have worked. We’ll know more once we start analysing our samples back in the UK. Anyway, back to filtering….

UK-Russia collaboration agreement

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We have just met with the director of the Institute of the Earth’s Crust, Russian Academy of Science, Irkutsk, Russia to discuss a collaboration agreement with the University of Nottingham.  Our collaborative partner is Elena G. Vologina, a sedimentologist who has worked extensively on Lake Baikal.

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Thanks for looking after us in the field Elena and looking forward to working with you.

Experiments under the ice

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P1020135 As well as sampling the lake, we have set up some experiments to simulate how nutrient enrichment might affect Lake Baikal phytoplankton.

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We have enclosed algae in two-litre mesocosm bags and spiked them with different combinations of nitrogen, phosphorus and silicon.

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We will leave the algae to grow for one week before harvesting and testing to see whether nutrient enrichment has changed the types of species that grow.  We will also analyse the algal material from the experiment to see whether silicon enrichment or depletion influences the silicon isotope ratios; this should help us to interpret what the changes in the sediment core material are telling us.