weeks 14-16: Rothera enters winter mode....

Two weekends ago Rothera hosted its annual Folk night. This is an event where anyone on base can perform on ‘stage’ in front of the entire base. This can be anything and this year included stand up comedy, singing, music (guitar solos, full bands, electronic dance), tapdancing and more.

The Dutch contribution consisted of a series of science related sketches behind a sheet using shadow play to depict Rothera 10 years in the future after the Dutch have taken over.  Everyone had a good laugh watching the Dutch stereotypes adapted into our four lab containers using scientific equipment.

Zoi preparing for her part in the shadow play sketch as a virus on a bicycle, pretending to be a dutch virus found in the Antarctic waters

We also took part in a play done by the Bonner Lab based on ‘the Bonner joke of the day’ where many jokes were made at the bar; with all sorts of actors: an English-man, Irish-man and a Scots-man, an octopus, a panda, a penguin, a bacteria, a monkey, a woman with a duck, a pirate, and other random creatures. We all had an excellent evening playing, listening and watching the plays from this exceptionally talented base!

So the season is coming to an end, the Twin Otters have all flown North back to Canada as well as the DASH 7, taking with it the last passengers to fly out. There are only 48 people left on base now, which can at times give you the feeling that the place has been deserted and quiet. From now on the only way out of Adelaide Island is by ship in late March, leaving behind the 18 brave winterers.

A Twin Otter leaving base. The last flight out of Rothera.....

The packing deadline of March 14^th is approaching fast (when everything returning to the UK by ship has to be packed and paperwork handed to the base commander) and it is surprising how long it takes to pack up the samples from the season with all samples separated by type of preservative.

The weather has been quite variable over the past three weeks with strong winds, snowstorms and low visibility affecting sampling frequency. Two weeks ago we were on our way to RaTS site 1 only to be called back due to a snowstorm reducing visibility. On the plus side I got to see my first Fur seal and boating around icebergs in the snow is a very surreal experience.

Fur seals are seen at Rothera late on in the season compared to other seals (Crabeaters, Southern Elephant seals, Leopard seals) that are now being seen less and less. Fur seals are easily overlooked as they camouflage so well with the ground, looking exactly like big fat rocks. One only realises its presence when very close to it by its ferocious roar trying to protect themselves and their own space from strangers. We have to keep an eye out while walking around the base as they can be aggressive towards people, chasing and sometimes biting.

On the other hand, very friendly and harmless Adelie penguins have increased and large groups can be seen all around Rothera point.

Going out sampling surrounded by wildlife is always a joy and there is always someone keeping a close eye on you.

Last week we wanted to compare copepod net hauls from our usual sampling time (in the morning) to net hauls taken just after sunset. Now it is actually dark at night we wanted to see if there was a difference between the stages of C. acutus (females and juveniles) found in the top 200 m of the water column compared to below 200 m at the two different times of the day. The weather prediction was good with 0 – 5 knots wind speed predicted all day, perfect netting weather. So we went out in the morning, collected the samples (3 hours work), processed the samples (another 2 – 3 hours work) and the weather was still perfect. Then 45 minutes before the sun was due to set at 21:38, the wind suddenly went from less than 5 knots to 15 knots and increasing, in only 30 minutes. This meant the evening boat trip was cancelled, because over 15 knots wind speed no boating is allowed and the drifting of the boat would be too large for accurate sampling. It was a pity as there was a brilliant moon ready to illuminate our predicted late journey. We will have to repeat the work another day.

Last week we ended a light manipulation experiment of nine 20 L samples after ten days of incubation. We saw different gradients of brown colour on the filters between the different light incubations and also the photosynthetic efficiency (PAM) measurements indicated differences. So interesting stuff is going on there that we will look into closer when back home.

Pulse Amplitude Modulation (PAM) fluorometry is a method to assess the physiological status of phytoplankton whereby water samples are subjected to a pulse of light, and the fluorescence produced by the chlorophyll (inside chloroplasts, the reaction centers of phytoplankton cells) provides an indication of the photosynthetic capabilities of the sample i.e. the capability of the phytoplankton in the water to turn light energy into glucose. Changes in PAM is often one of the earliest and most sensitive indicators of physiological stress.     

The bad weather breaks have however enabled us to optimise the protocol for setting algal pellets into resin for analysis via Transmission Electron Microscopy (TEM). As briefly discussed in the last blog, very little is known about diatom succession and dynamics along the Western Antarctic Peninsula, and even less is known about the role of viral infection. One method we are using to assess the frequency of viral infection is to use a continuous centrifuge to concentrate algal cells from large volumes of seawater (10 – 20 litres) into a small pellet which is then set into a hard resin block to be sliced very finely and observed under a transmission electron microscope (TEM) back home. A TEM uses a beam of electrons transmitted through the specimen to form an image of particles thousands of times smaller than can be observed under a light microscope. Using this technique we hope to visually inspect the inside of algal cells for the presence of virus particles which will provide an infection rate.

Thinsection images using TEM: unicellular algal hosts infected with viruses. Photos provided by Corina Brussaard.

Saturday was a base wide day off as a nice way to reward the entire base for its hard work over the busy summer season. The four field assistants organised outdoor activities that varied from abseiling and exploring a newly formed crevasse, to climbing ice walls and trekking along Reptile Ridge. We joined the mountaineering course that consisted of learning how to use different knots, how to use the ‘jingly janglys’ in a standard crevasse rescue kit, how to abseil and climb up a rope using a climbing ascender and so on. After few hours of theory and indoor practice we finally went out on this great sunny day, up the glacier (known as The Ramp) to practise a crevasse rescue. We grouped into couples and while one was pretending to fall into a crevasse (sliding over the edge of a small ice cliff) their partner had to throw themselves onto the ice using your ice axe to make sure you were not dragged down as well, and then secure the rope to the ice with snow stakes and various other bits of kit you have on you. The next step is to transfer the load from yourself onto the snow stakes which releases the load from the person who is currently stopping their partner from falling to their doom! Next you set up a rescue pulley system and pull your partner out of the ‘crevasse’. We are now ready for some good old adventures outside of the immediate local travel area.

Tristan learning how to use ice screws	Zoi hanging off a small ice cliff during crevasse rescue training

Left: Tristan learning how to use ice screws; Right: Zoi hanging off a small ice cliff during crevasse rescue training.

Over the past few months Tristan has been getting into the Antarctic spirit by growing his beard. Although not even close to some of the outstanding beards grown by the overwinterers, it has definitely reached that next level of beard appreciation by the number of comments it has received over the past couple of weeks…….

A British Navy ship (The Protector) is due to pay a visit on Monday where there will be the annual Rothera Olympics (rope-climbing up an ice wall and run to the top of Rothera point, crossing a section of the water on a piece of rope and a football match) followed by a curry lunch on board the Protector. Snow and wind of 35 knots is predicted so we will get back to you on that one!

We leave you with some sounds from the Rothera Folk night. The first is Dale the plumber and Chris the new wintering electronics engineer singing Rotterdam, and the second is some electronic music by Antrancica (Adam the comms manager and Tom the old electronics engineer) called No Known Traffic. Enjoy!