One of the nice things about McMurdo is if you wake up too late for a shower, simply walking between the buildings en route to work does a good job of waking one up.  Today was no exception.  Here are some grabs from the weather station that lives on the building next to the lab:

Always a nice way to start a monday…

Talking to a friend down here, he said “days and months can drag by like they are never going to end but weeks always fly by.”  That was sure this week.  We collected a few samples on Monday but the most memorable part of the dive was that we were mirrored by a seal the whole time.  He didn’t feel like getting his photo taken as is clear from this grainy shot below:

This seal was constant company but would not hold still for a good photo.

Rory labeling away. This week we sliced our cores into a total of 288 different containers to undergo a variety of processing later.

But the main task for the week was breaking down one of the big time points of our experiment. The cores have started to take on their mind of their own and integrate the food we have given them.

Here is one of our cores mid processing. Each one of the syringes go to a different analysis and the rest of the mud that is not in those cores gets sieved and the species separated out from it.

The processing involves getting a bunch of sample vials and bags labeled and then sub coring the mud with a series of syringes that we have cut the tops off. On Tuesday and Thursday we processed a total of 24 cores, which made up four replicates and each of our six treatments. One of those subcores gets sorted live under a scope and that is how I have spent my waking hours since Tuesday. Here are some of the things I have been looking at:

Spiophanes:

Today we headed out to the more beutiful of our two main dive spots in search of an old cage put on the seafloor many years ago and for me to continue my search of worms. As part of the dive we also got to release an octopus that had been collected as bycatch by one of the fish physiology groups working down here. Their research team collects fish from shallow to ~600m using a variety of methods including using fish traps. In addition to the fish species he collects he also occasionally gets octopods. This creates a bit of a conundrum. While he could release the octopods right back into the wild – the octopods have a very poor chance of survival. Seals will hang out around his team while they fish and an octopus can use its many forms of camouflage on the seafloor, in the water column it can be more aptly described as bait. The only other option is to take them back to the station until some divers can escort the octopus down to the seafloor where it can return home under the cover of benthos. As part of our dive today, we performed that service (it took very little arm twisting to get us to do this).
Here is our friendly octopus trying to escape from his enclosure in the water tables next to our lab. He was moments from freedom (in this case death, rather than actual freedom as he would not do well on the floor ) when I stumbled upon him, snapped this photo, and the gently pushed him back into the water. You can see his arms here floating above the rim of the mesh cage that we had him temporarily housed in.

At the beginning of our dive, Rory put the octpus on his hand and it stuck. Actually it stuck both of his hands together but since that meant Rory couldn’t adjust his buoyancy, he had to coax the octopus onto only one hand. The octopus stayed on that hand the entire way to the seafloor.  After it they reached to bottom Rory had a bit of difficulty getting the octopus off as it seemed pretty content to be on him rather than free. As soon as he got the octopus to let go it took off and stuck to my hand for a while. Apparently this individual likes dry gloves as much as we do.Then the octopus settled down and relaxed on the seafloor as we went looking for the old cages and I continued to look for dense worm communities.

We ended up finding the cage and taking some photos. These cages have been in place for more than 30 years. Everything that is on them that cannot move (what we call sessile) gives us information as to how fast things grow here. For example sponges. The cage was about 3ft high – the same size as these sponge below. How old do you think they are?

Today was a good one.  We started out in the lab processing samples from an experiment that we broke down on Saturday.  Like all weekends we spent the last one working and putting samples into the freezer and preservatives. It feels great to be making progress towards the end of our project, even though that is still a month and a half away.  As we were typing away Rory noticed a lot of people on the ice and pointed them out.  Well it turned out to not only be a lot of people but a quite a few people and a group of very lost emperor penguins.

Its rare to see Emperors here as they normally roost during the winter on the far (far!) side of the island at Cape Crozier. Cape Crozier is 55 miles as the penguin waddles from here adding around 100 miles to these penguins journey. There appeared to be quite a bit of dissent among the ranks as they often stopped and grrrred at each other while walking by the station. This group was likely females on their way back to feed the chicks that they hatched over winter.

The rest of the day we spent jumping in the water to finish an experiment.  We had noticed that as the light become more abundant during the rapidly approaching summer, diatoms appeared on the sediment surface. Diatoms are plankton (i.e. microscopic plants of the sea) and are a potential food source for animals. We decided to measure how much energy these emerging diatoms were producing by doing an in situ (i.e. underwater) experiment.  To measure this we took cores and blacked them out (using some handy electrical tape) and left others clear (replicated at all of our sites, of course). The black cores would let no light in so we knew there was no photosynthesis going on and the clear cores did let light in allowing any plants present to act normally. One black and one clear core were used to collect sediment without disturbing it, and then placed upright overnight on the seafloor. We let them sit there for 24 hours and then measured the amount of oxygen in the cores (we had also measured the oxygen concentration in the water when we set out the experiment yesterday). The difference between the starting oxygen and the ending oxygen of these cores told us how much oxygen was used by the community that we trapped in our cores. Since we know that photosynthesis produces oxygen, the difference between the clear cores and the dark cores tells us how much photosynthetic production is occurring. In other words: Photosynthetic production (measured by O2) = Oxygen produced by photosynthesis – oxygen consumed by the community. The clear cores integrate both the oxygen produced by photosynthesis the amount consumed by the community and the dark cores only measure the amount consumed. Simply by subtracting the amount of oxygen in the dark cores from that in the clear cores to get how much net photosynthetic energy is being produced. The answer? At this time of year the seafloor photosynthetic community is producing ~ 19 mg O2 per square meter. We can use this number (after repeating the experiment a few more times throughout the year) to come up with an estimate of the amount of food benthic (seafloor) production provides for the animals that live in and on the sediment. To put that in perspective, that is about 25% of the daily food used by this community today.

Not everything works as planned though. For example we had issues with sea urchins deciding that they wanted to climb on top of our treatments, knocking them over (this treatment was to measure what was going on in the water – hence no sediment). Not to mention another one deciding that my station marker would make a nice addition to this particular individuals camouflage.

At the end of the dive we took our samples back to the lab to measure the oxygen and saw a nice fish along the way. This is Trematomus bernacchii, one of the fish we often see here, hiding underneath Alcyonium antarcticum, a soft coral.

Now that we are finished with all the sea floor sediment sampling for the big experiment we can to go back and dive our Cape Armitage dive hole, which I’ve been looking forward to revisiting for quite some time.

Sampling sea-ice interface at our Cape Armitage dive hole.

I’m not saying that our normal dive site at the Jetty isn’t cool, but for a majority of the dive we’re focused on 5 X 5 foot section of mud. Well… I think Andrew’s focused for the majority of the time, but I’m still in awe and easily distracted. We have had SEALS swimming around us and calling back and forth to each other while we’re working on our past three dives! How cool is that? I mean you’re not going to NOT try and swim off and play with them…

Today was zero sediment collection and the only goal for the dive was for me to collect three syringe samples in order to determine if there are any of the bacterial predators I’m studying for my PhD research in the Antarctic. While I sampled Andrew photo documented the dive site. My sampling is super quick, just a syringe from the sea-ice interface, another at 15 feet and one just off the sea floor, which leaves a lot of time to explore. Cape Armitage is such an amazing dive site. I can’t write the exact words to tell you how incredible this site is, but I can show you what it looks like through the lens of Andrew’s underwater camera.

Giant vase sponge on Dayton’s Wall.

The sea floor at the Armitage dive site is very steep almost like a wall or a cliff with all sorts of life clinging to it. Above is the shot Andrew got looking almost straight up, and you can see our dive hole and down line off to the right.

While one of the few sites in the Antarctic that includes a view of a man-made structure, the Jetty is still quite beautiful. Seals often hide in the shadows seen to the right to keep a watchful eye on the intruders into their blue realm.

Cores for one of our replicates.

Today we did yet another dive at the jetty. The great part about it was that we collected the last of our samples for what will be the largest experiment of this expedition, harvesting mud from the site we spent the first 6 dives identifying and the next 8 days sampling. This was also important as we needed to get these samples before the sun was always on the seafloor.

Beroe just after gulping some water or food – its food is too small for me to see. The iridescent combs paddle along its so it can move.

Upon entering the water we were met by many large ctenophores (Comb Jellies – this one is a Beroe) that were around 6-8 inches long. I had never seen them feed before and this species gulps water with its mouth, very reminiscent of how a whale shark feeds, only smaller.

Rory collecting samples for microbiological analysis.

Rory decided to do some collections for a pilot project that may tie his coral reef work directly into the habitats here, in this case using a syringe to collect water from a variety of locations.

Rory taking the samples back to the dive hole. Above you can see a tidal crack which is the reason that we have to take sea ice safety classes. A hazard from above and beautiful from beneath.

Rory was nice enough to take the core rack (as we call our much-loved milk crate) back to the dive hole while I trailed along taking a few photos for the day.

A blue safety stop.

We end every dive with a safety stop right below the hole. This is the coldest part of the dive as we have been slowly chilling throughout the dive and now have to sit close to the warmth of the dive hut but still in the freezing water.

Here is our dive tender for the day, Chuck, waiting to help pull our gear out of the water.

This is the view that ends every dive – a dive tender waiting to collect our equipment and help us get out of the water. We can’t dive without them and it also allows us to meet more of the wonderful people on the station that make our science possible.

It was spectacularly beautiful outside when we headed out with the instructors of the Field Safety Training Program (FSTP) to wrap up our final in field sea ice training. The class was small, about 10 people including Andrew and I, and included a diverse group of skilled workers from all over station. We all piled in the FSTP hagglund and headed out of McMurdo Station for the sea ice.

Hagglund

We started out practicing how to make ice anchors (V-shaped holes in the ice that we pass rope through) to make sure ourselves and our gear doesn’t get blown away in rough weather. Then we all profiled a small crack together with the instructors and popped in our dive hut so everyone could visualize just how thick the sea ice is right in front of station. Next we traveled to Hut Point to profile our first major pressure ridge crack. We cleared layers and layers of snow (shoveling and more shoveling) to get down to the sea ice before we drilled a series of holes perpendicular to the crack taking measurements as we went along to map out the profile of the crack.

Pressure ridge profile

These measurements allow us to determine which types of vehicles are safe to cross. One of the major cracks that form every year around hut point is named Big John after the big john tractor which fell through years ago.

Pressure ridge near Hut Point

The course ended with a trip out to the ice runway road where we got to take a look at some very unusual cracks around the permanent ice shelf and the multiyear ice intersection. We were basically about a half mile out to sea with impressive views all around, which was easily my favorite part of the day, because we got to see a different perspective of Ross Island and the surrounding areas.

View of Mount Erebus from the sea ice

The past few days have been a blur.  The weather turned south on us (or I guess that saying should be ‘from the south’ as that is where the big storms come from here) o 50 n Tuesday night. Guests were overknots and the visibility dropped to <25ft.  We were shooed out of the lab since it was likely to set in for the night and reach ‘ condition one’ which means we cannot leave the building we are in.  There are not great places to sleep in the lab so an early night to bed sounded like the way to go.

This is the solder that had been plaguing our oxygen instrument since we arrived.

During the day however, I was able to find a solder that had come loose and had been plaguing some of the sensors that I use to measure oxygen.  After taking apart the wire, discovering the broken connection and asking the instrument technician here to solder it for me (being far better at soldering than I), we all of a sudden have three backups for our very delicate oxygen sensor.  Life is better.

It was a cold day. This is me after warming up for a few minutes. I would have pulled my neck warmer down but it was frozen in place. But we got our new dive hole in and have an excuse for more hot chocolate now.

We then snuck out in, what can only be called, bad weather to put in our new dive hole.  The wind was blowing strong and while it was ‘warm’ at -16 C the wind chill was down to around -51 C.  Rory and I were doing much better than the drill operator who had no choice but to sit face into the wind for around an hour.  We dove the site the following day and while an amazing location the worms that we were after were not there either (the photo at the beginning and end of this post are from that dive).  We have decided to spend our time from here on out looking at the community that we know where it is (the jetty) and abundant while the others remain… somewhere.

At the top of this sponge you can see a little blurry bit which is Anchor ice. This sponge is not long for this world.

Anchor ice is a prevalent occurrence in McMurdo Sound.  Anchor ice forms on pretty much anything in shallower water and as soon as one piece forms it acts as a nucleus for more ice to form.  As this continues it is the equivalent of someone blowing up a balloon very slowly (as ice is less dense than seawater) and it floats up to the surface, killing the animal that it attached to.  That’s one reason we don’t work shallow here – the ice constantly disturbs shallow communities but occasionally it extends deeper down.  This particular example of anchor ice is growing on a sponge (Homaxinella balfourensis) at 70ft deep.  The deepest I have ever seen it.  Normally it peters out around 40-50ft and very rarely goes as far down as 100ft.

The other neat thing about the site was that there was an incredible abundance of octocorals blanketing the seafloor making it look like snow everywhere.  This dive really reminded me why I love diving in the Antarctic.  Even in this time of year when there is so little light, the diving is much better than the training dives we did in Oregon to get ready for this trip.
Today’s dive:

The white along the seafloor is the octocoral Clavularia
frankliniana

This is our last training dive off of Newport, Oregon. It is quite hard to put on all the gear that we are now using in the Antarctic on a warm summer day in the states, only to get in the water to visibility of a few feet.

Today was our day off for the week. So what did we do.. worked. After a leisurely morning of too much food and great company we headed down to the dive locker. The people that we talked with at breakfast are getting ready for the south pole traverse.  This traverse is   how all of the supplies, scientific and otherwise, are taken to the south pole. Driving across an always changing, crevasse filled continent is no rapid matter. It takes them the better part of two months living on the ice and driving at… get this… an average speed of 7 mph to make it to Pole. The main discussion today by the Traverse Crew was the best way to broadcast music between the different tractors to make the drive more tolerable.  Supposedly the scenery is epic.

Our dive site was the good old Jetty. We collected the last of our cores from this site until the end of the season at which point we will take another set. Rory’s glove leaked and so we did only what we had to do and then headed back to the warmth above. It is hard to get frost bite underwater but it is easy to have a very cold painful hand. Rory toughed it out so we got our dive tasks done but if you want to know what he went through, make a bath of salt water, fill it with ice and hold your hand in it for 30 minutes. It is that much fun.

However the best news of the day came when we got the results of one of our ongoing experiments. In this experiment we are trying to identify which antibiotic is most effective against marine sediment Microbiota in the Antarctic. As one of the linchpins of our project revolves around removing microbial activity and antibiotic effectiveness is different wherever one goes, this is a important aspect to our study. To test this we added yeast extract (i.e. bacteria food) and five antibiotics into filtered seawater with 1 ml of sediment. We measured oxygen uptake as active bacteria will use the oxygen much like we do and we can easily identify those antibiotics that cause the greatest change in oxygen uptake. The more oxygen used, the less effective the antibiotic tested. We also had two controls – one with no yeast extract and one with yeast extract and no antibiotics. Clearly ever antibiotic tested worked well in the Antarctic habitat (see the figure to the left).  This is likely because, unlike most places on the planet where antibiotics from human and agriculture run off expose even marine bacteria to a suite of antibiotics allowing their populations to adapt to many different antibiotic forms.

Today we awoke with a message from our Sea Ice Training staff notifying us that there will be an outdoor component to the course and we are to pack and wear our extreme cold weather (ECW) gear. In order to know what items from my ECW gear to pack I did a quick check of the weather:  -40°F with 20 knot winds…so…EVERYTHING. I wore every layer that they gave us and although I looked like the marshmallow man I felt great out on the ice. They cancelled the outdoor portion of the class for the rest of group, but Andrew and I went out with the instructor after the classroom portion to profile a safe route to the site of our next ice hole. A BIG thank you to Jennifer Erxleben and the Field Safety Training Program’s crew for allowing us to get on the ice and survey our next dive site so we can get our samples as soon as possible.

Before we headed out to the ice Andrew and I climbed to the top of the radar platform above Crary to have a better look at the area where we planned to explore today. The morning light made the surround areas look amazing. We used some of the techniques from this morning’s class to assess sea ice conditions and travel safely on the sea ice to the GPS coordinates for where we wanted our next ice hole to be. We used the longest handheld drill and drill bit I’d ever seen to profile the cracks in the ice around our next dive site. After a series of measurements we determined the location was safe and the ice was nice and think, 1.5 meters, along all the sea ice cracks near our site. We’re scheduled to drill the dive hole tomorrow morning with the help of the drill team and dive our new site in the afternoon.

Assembling the Echo drill and kovacs ice drilling equipment

Sea Ice Training

Sea Ice Training