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

Today started out well.  After a mad dash run in the lab to see the effectiveness of some antibiotics on the bacteria in the Antarctic we went to our local dive site to search for more high density worm beds. 

We found a good set of worm tubes and began to core (see core sample image from Sep 5 below).  They are not the best cores (a little shallow on the sediment side due to the brick wall of volcanic rubble that sits underneath the mud at this site).  Another slightly more amusing challenge was that apparently I have one core that is slightly too small for the caps, and while I knew that this core tube existed I didn’t tell Rory and accidentally took it diving. He spent a good few minutes on the bottom trying to put a cap on a core that was too small.  When I saw what was happening I realized he must have smaller core tube and pulled the core out of the sediment and handed him a new core tube.  He was so confused… not that you can tell through a mask.

After the dive we worked in the lab trying to make more progress on the lab set up, and the day disappeared with odds and ends and errands.  Some of these task were science related such as, building a core resperometer (so we can see how much the sediment “breathes”) and others were safety related like, loading up our vehicle with our survival gear bags meaning that if a storm comes in we can be quite ‘comfy’ in nothing more than our vehicle for up to three days.  I also started to look at some of the animals under the scope.  It always amazes me how things that I have looked at for years preserved look totally different in real life.

The day ended in a first for me – we saw Aurora Australis, or the southern lights.  After sitting in the -43°F wind chill air for around an hour taking photos my camera decided to call it quits and froze, we called it a day too. Electronics do not “like” the extreme cold, LCD screens freeze, batteries have a fraction of their original life, etc. which is just one of the many challenges for science in this harsh continent of Antarctica. We gladly endure these challenges for good scientific results and the added perks of new experiences, such as the Aurora Australis, always help.

We had a visitor to our dive hut just before hitting the water today. A Weddell Seal!!!

Weddell Seal (Leptonychotes weddellii) Not the one we actually saw.

As soon as we  stepped into the hut and closed the door a Weddell Seal pup popped up in our dive hole for a breather. The little guy splashed around for a bit and seemed to be just as interested in us as we all were in him, peering up at us with his big doe eyes. I should clarify the Weddell Seals can easily weigh over 200lbs just 6 months after birth (and this guys was over 200lbs). He didn’t linger much longer than 30-45 seconds before disappearing back down the dive hole.

We could hear him calling out to his buddies through the ice as soon as he passed out of sight. A great start to the dive trip.

We followed shortly after down the same hole and collected all 9 of the samples we needed to start testing our experimental design. Fingers crossed that all goes well and we can start gearing up for the big experiment without delay.

Today wasn’t a bad day by any stretch of the imagination.  We got in the water to do our first science dive, got trained on our vehicle and issued it, and obtained our first samples.  However even though we got all that done, few things went as planned.

Our vehicle is a Piston Bully.  Normally found on ski slopes grooming the steep hills, this tracked vehicle can cross ice, snow, rock, and just about anything else that one throws at it.  However it is also delicate and doesn’t like the cold (?) so must be babied.  The lesson on how to baby it took 2.5 hours this morning.  I’m not bitter about this long lesson as it is a very different vehicle than most and I learned a lot.  For instance, I learned that the heater in this particular one was broken.  A broken heater in the Antarctic?  Not going to work.  Thankfully there is a great group of mechanics here that got to fixing it and fixed it right away.  

We had planned on a post lunch dive at the Jetty (the only dive sight that is open.)  1:30 seemed pretty civilized however at 1 the wind kicked up to 50 knots, the visibility went to <10ft, and walking became difficult.  Although the weather underwater would have been nice it meant we had to postpone our dive.  While that would normally be a bad thing it meant that we discovered a large leak in the aquarium and helped another science team catch the water overflowing from their aquarium onto the floor (someone else accidentally turned up their water pressure and knocked a hose spraying seawater onto the floor without noticing – flooding entailed from both).

This was the wind – the building in video is ~25 ft away.

Then the weather cleared and off we went.  This dive went OK.  I forgot a key piece of equipment in the vehicle and had to stop mid dive to get it and continue the dive.  Both Rory and Rob stayed down and then I went looking for the community that we planned on studying with little luck.  All in all we got three samples.  They are the first three samples of the season but a few less than the 9 planned. So tomorrow we go back in search of more.
 

An Anemone and Soft Coral on the sea bed.  You can also see the siphons of clams right next to the base of the anemone and little tubes.  In those little tubes are the worms that we are after, but this community is no where near as dense as the community that we are down here to study.