Penguins, ahoy!

Just to the east of the Ross Sea lies Cape Colbeck, our next destination. Here, ecologist Dr. Gitte McDonald is hoping to find some Emperor Penguins. In the past, Gitte has had some of her Emperors come to this area to molt. But, no one knows where they go or what they do after molting, until they are seen heading back across the Ross Sea for breeding. Gitte and her team are hoping to catch and tag Emperor Penguins to shed some light on this mystery.

Whereas we were mostly in open water during our Ross Bank surveys, now the N.B. Palmer is heading into the ice. At this time of year (e.g., late summer in the Southern Hemisphere), we didn’t know what the ice conditions would look like at Cape Colbeck. Luckily, the ice cover was more than we expected – and the ice was covered with penguins!

Ice flows off Cape Colbeck. On the look out for penguins!

Spotting penguins on the bridge. Colin, one of the Marine Technicians, makes a plan for how to safely reach the penguins.

Gitte and her team off to an ice flow to tag Emperor Penguins.

One tagged Emperor and others waiting to be tagged! Photo courtesy of Sarah Peterson, ACA permit #: 2023-003.

It’s important to note that not just anyone can jump into a zodiac and get onto the ice with penguins. Well before the cruise, Gitte had to secure the necessary permits and training to handle Emperor Penguins. And, there are a lot of rules to follow to ensure both the scientists and the penguins stay safe! So, that means that we couldn’t join Gitte’s team out on the ice, but we did have some important jobs onboard!

While the penguin ecologists were out, we geologists were wrapping up sample processing and moving our samples into the cargo hold for shipping. However, we did get some chances to be penguinologists!  While “penguinologist” isn’t an actual term, it’s one we’ve adopted on the Palmer. As penguinologists, we watched from the bridge to look out for groups of Emperors and to keep eyes on the zodiac in the ice. I’m definitely adding this to my CV!

After some successful penguin tagging at Cape Colbeck, we moved more east into Marie Byrd Land, towards the Saunders Coast. While at Cape Colbeck, the N.B. Palmer could either drift in open water or use dynamic positioning to stay in the same spot if there were some large icebergs nearby. Here, the ice cover was too patchy to drift so the Captain decided to “park” in the ice to save fuel.

Parked in the ice overnight.

While Gitte and her team were out with the penguins and we were not on official penguinologist duties, we had the opportunity to take out the zodiacs for a spin. Part of the adventure is actually getting INTO the zodiac (you climb into via a rope ladder hanging over the side of the ship). These trips were probably the closest we got to being “tourists” in Antarctica, but they were also training runs for some of the crew who were interested in driving the zodiac on future expeditions. While we maintained distance from the penguins, especially the ones Gitte and her group want to tag, we did get up close and personal with some cool icebergs.

 Obligatory “Hey, Mom! I’m on a zodiac in Antarctica!” picture.

Our home away from home, the Palmer, with a group of Emperor Penguins.

Gitte and her team brought 33 penguin tags with them, and used all 33 of them! Once they completed tagging, they deployed net tows (much larger than our plankton nets) to figure out what the penguins were eating. In fact, they used up all their tags ahead of schedule, so we were able to squeeze in a mini multibeam survey around the Eastern Ross Sea, which is one of the most poorly mapped regions of the Ross Sea. Unfortunately, we had to cut our bonus survey short and head north to avoid storms that were forming in our transit path across the Southern Ocean back to Lyttleton, New Zealand.

Until Next Time, Ross Bank!

After 10 days completing multibeam surveys and Super Sites along our North-South transect of Ross Bank, we switched directions to conduct our East-West transect and finish our science days.

While mapping the shallowest portion of Ross Bank, called the bank crest, we noticed a large iceberg. Normally along our transects, we notice icebergs here and there but we kept coming across the same iceberg at the same spot. As a refresher, when you see an iceberg, you are only seeing the top 10% of the actual berg that is floating above sea level. The other 90% is below the surface. When icebergs encounter a shallow region like Ross Bank, they can get stuck – or grounded. We think this berg is grounded! Since we’ve only been seeing water for a bit, it was nice to have a landmark to keep track of during our survey.

Iceberg grounded on Ross Bank. Photo courtesy of Rachel Meyne.

After finishing our initial multibeam and subottom survey, we chose coring sites. Because the Jumbo Piston Core (JPC) was still configured from our last transect, we cored all the sites where we wanted JPCs first, before conducting the remaining super site coring (e.g., multi and kasten coring). However, before we core, we conduct water sampling to ensure we aren’t sampling mud from our coring operations. The shipboard chemists had quite a sampling marathon.

Chemical Oceanographer: Samantha Schwippert

Sam is a first year Masters Student in Dr. Kanchan Maiti’s lab at Louisiana State University. Dr. Maiti is also sailing with us! As chemical oceanographers, they are interested in understanding carbon flux in the Ross Sea, especially in the coastal regions and at the ice-shelf edge. In the Ross Sea, the formation of cold bottom waters and phytoplankton blooms act together to move inorganic and organic carbon from the atmosphere and surface ocean into the deep ocean, where it is removed from exchange with the atmosphere. Together, these processes make the Southern Ocean, and especially the coastal regions of Antarctica, an important global carbon sink (30-40% of the global CO₂ uptake occurs in the Southern Ocean). Why is this important? Well, studies indicate that, within the Southern Ocean, the Ross Sea region is an important sink for anthropogenic (human derived) CO₂. This means that, presently and in the past, the Southern Ocean plays an important role in regulating atmospheric CO₂ concentrations and Earth’s climate system.

On the Palmer, Sam samples water from Niskin bottles on the CTD rosette, McLane Pumps, and underway sampling – plus sediment from the multicores. During CTD casts, Sam tells each bottle on the rosette to close at a different depth in the water column, resulting in a suite of samples from the water column. When the rosette is recovered, she samples the water from the bottles for nutrient content, oxygen isotopes, and natural uranium series isotopes that can track sinking particles; she also filters samples for particulate organic carbon. Sam’s favorite part about life on the Palmer is meeting everyone, the penguins, being able to experience Antarctica, midrats (a term for the midnight meal on our 24 hour ship) -really everything!

Sam sampling from the CTD rosette.

Back to Ross Bank. Once water sampling was finished at a site, we deployed the JPC! Since the JPC core barrel is typically longer than the Kasten core barrels, we can collect longer sedimentary records that extend. However, we have to wait to open these cores until they’re back at the repository. We do get a look at the sediments as we cut the core into sections onboard, but we’ll have to be patient to see the rest of it!

Cutting the Jumbo Piston Core liner as it’s pushed out of the core barrel. That’s me using the pipe cutter to cut the core linter into 1.5m sections – thankfully, I didn’t drop anything in the drink!

While JPCs are usually lined with white high density PVC pipe, we got the chance to try out clear PVC tubes similar to those used in the International Ocean Discovery Program (IODP)! Here we are (above) showing Phil, the Principal Investigator on our cruise, one of the JPCs we recovered. It is not a full barrel, as you can see from the muddy water visible at the top of the tube.

After finishing all of our JPC stations, the marine technicians reconfigured the winch for our other coring objectives. While the JPCs were a nice break from sampling, we were ready to get muddy again and jumped right into multi- and Kasten coring.

Opening the last Kasten core of our cruise! We had a lot of work ahead of us. Because the previous core was still on the table, we had to finish that sampling before we could start sampling the new core.

And with that, we finished up our science days onboard the RVIB Nathaniel B. Palmer. Over our 30 science days spread across NBP23-01 and NBP23-02, we:

• acquired 7,740 square kilometers of new multibeam bathymetry data
• collected >30 meters of sediment core – over 1,000 lbs of sediment,
• sampled >3.5 TONS of seawater,
• cleaned out the Palmer’s ice cream freezer.

But, it’s not goodbye to Ross Bank for Phil and his team – they’ll be back next year to expand our initial multibeam survey and obtain more sediment cores. For now, we will head west across the Ross Sea towards Cape Colbeck, where the penguin ecologists hope to find some Emperor Penguins to tag.

A Day in the Life: Station 1

As we arrived at our first study site, there was excitement in the air. We were surveying a site in the Pennell Trough, Ross Sea that may provide clues to how the Ross Ice Shelf retreated in the past (Fun fact: My lab mate, Imogen Browne, is studying the paleoenvironment of the Pennell Trough in the Miocene, ~14-16 million years ago). While we chose this site based on geophysical data, this was also a great water chemistry sampling site. As such, we called this first site “Super Station 1” and deployed three types of instruments/samplers:

CTDs are one of the most common instruments used in oceanography. The name stands for conductivity (salinity), temperature/transmissivity, and depth. While the CTD is a series of sensors that measures basic physical parameters, we also deploy a rosette of Niskin bottles to sample water at different depths through the water column to analyze water for biological (e.g., phytoplankton assemblages) and chemical (e.g., nutrients) parameters. We may not be GEOTRACES trace element rosette experts on this Palmer expedition, but we can hold our own.

      The rosette, post deployment in the Baltic Room of the NB Palmer. The Baltic room is enclosed and lets us deploy the CTD in rough weather, and sample the Niskins away from the elements.

On our expedition, we are collecting sediment cores to assess the response of the Ross Ice Shelf to past climate changes. To collect sediments from at and below the seafloor, we deployed a multicorer and a Kasten corer. The multicorer looks similar to the rosette, but with ~8 clear plastic tubes about 1 meter long that, when triggered, collect multiple the upper 1 meter of sediment. The multicore is useful because it enables us to sample the sediment-water interface with little or no disturbance. This is really important for Paleoceanographers trying to reconstruct the last ~1000 years of climate or for regional proxy calibration and 14C reservoir corrections (more on this later). Kasten cores are special gravity cores designed to recover larger volumes of sediment and to be sampled shipboard. The Palmer has Kasten Core barrels between 3 and 9 meters long. The real trick with the kasten core is to determine how much weight to put on so that you collect a long enough sequence, but don’t over penetrate and blow out the sediment-water interface. We use the multicore and the kasten core together to get a complete sediment sequence of the upper 3 to 9 meters of sediment.

A kasten core coming up on the back deck. That red box is what the Marine Technicians (MTs) use to rest the core barrel on while they secure the weight stand.

My onboard research

On this cruise, I am wearing a few title hats: sedimentologist, micropaleontologist, and organic geochemist. My main job is to search the sediments for tiny microfossils called foraminifera – a single cell zooplankton that secretes calcium carbonate shells, called tests; in Antarctica, a lot of the benthic foraminifers (that live on or in the sediments) make their tests out of grains of sand and anything else they can find. We’re really hoping that the sediments we collect contain foraminifers made out of calcium carbonate because their tests record past ocean physical and chemical parameters. For my research, I am sampling the multicores and the kasten cores.

When I sample the multicores, my main focus is to differentiate between living and fossil organisms in the sediments. To do this, I add a protoplasm stain to the samples called Rose Bengal. This bright pink stain enables us to separate the living and recently dead organisms from fossilized organisms (with no remaining protoplasm). This process takes a few days, and I monitor the pH so that I don’t inadvertently dissolve any calcium carbonate. I then wash the fine sediments from the sample, dry the residuals in an oven for 24 hours, and then put the samples into well-labeled vials for future study! Over the years, my advisor has learned that it is best to wash for forams on the ship because Antarctic sediments and their overlying ocean waters can be corrosive to calcium carbonate. You can return home to find sediments with little or no remaining calcium carbonate.

Washing the multicore samples: You can see the stained living to recently dead organisms in this sample! Two organisms from this sample included a bivalve (top) and a benthic foraminifer (Globocassidulina spp.)!

When we sample the kasten cores, my first objective is to collect samples for radiocarbon dating. These samples will be analyzed in Dr. Brad Rosenheim’s USF lab. Radiocarbon dating is extremely important because it enables us to determine when the sediments were deposited. After we sample for radiocarbon, we sample for organic and inorganic geochemistry and micropaleontology, which will help us understand past ocean temperatures and paleoenvironments.

Also on the boat…

One thing that is great about this research expedition is that there are a lot of students from different PI groups at different universities. Let’s hear from some other students about their first day of sampling!

Environmental Scientist: Alyssa Cotten

Alyssa is an undergraduate student in Dr. Wade Jeffrey’s lab at the University of West Florida. Her research focuses on quantifying bacteria and phytoplankton production (a fancy word for growth) using radioisotope tracers. She sampled water from the top few niskin bottles. She also sampled one of the multicores to test her method in the sediments. Her favorite thing about life on the Palmer is her roommates (author’s note: she didn’t feel pressured into saying this because I am one of her roommates) and seeing snow for the first time!

Alyssa in the “Rad Van”, a shipping container on the Helo Deck where all radiotracer work is done. It is really important to avoid tracer contamination onboard because some scientists (like me) are looking at natural levels of the same elements.

Marine (Geomicro)Biologist: Caleb Boyd

Caleb is a first year Ph.D. student studying geomicrobiology with Dr. Brandi Kiel Reese’ at the University of South Alabama and Dauphin Island Sea Lab. What a way to start out a Ph.D.! For his project, he is sampling the CTD, multicore, and Kasten core – the whole suite of tools we deployed. When he samples, Caleb “protects the samples from himself” – making sure that his microbiome does not contaminate the samples. In their lab onboard the Palmer, Dr. Kiel Reese’s team set up a “clean bubble” by hanging plastic sheets around their equipment to prevent contamination. Caleb will determine the metatranscriptomics (broad scale view of the active microbial community), cell counts (in a known sample volume), and will even grow (called culture) some of the microbes to determine what lives in the water/sediment. This type of research is important to understand the outsized role that tiny microbes play in nutrient cycling and larger biogeochemical cycles. Besides meeting new people and learning about different research fields , Caleb’s favorite part of life on the Palmer is rocking and rolling in the Southern Ocean’s huge ocean swells.  

Caleb with his multicore sediments.

Over the last few days, we have sampled another superstation and took an add Kasten core! For now, I’m staying busy washing sediments in my search for living benthic organisms and microfossils. Next stop: McMurdo, Station!

Transit and Arrival in the Ross Sea!

Hello from Emily in the Antarctic! We’ve had quite the journey south onboard the RVIB Nathaniel B. Palmer. We left Lyttleton, New Zealand and transited to the Ross Sea, Antarctica over ~10 days. Leaving port we had beautiful weather and were escorted by the pilot and a few local Hector’s dolphins.

Lyttleton Harbor, New Zealand

As we transited south, the sun stayed up longer and longer. During our last few dark nights, we stargazed from the Palmer’s helo deck. Back in the day, explorers would follow the Southern Cross towards the pole. Now, we have GPS, but the Southern Cross is really cool (just ask Matt Hommeyer, Amelia’s husband and CMS’s multibeam wizard. Rumor has it he got a tattoo of the Southern Cross onboard the Palmer in 2001). Also, now that we’re closer to the South Pole, it is light almost 24/7.

Stars from the Palmer’s Helo deck

As we transited farther south, the seas began to get rocky. We left New Zealand coastal waters and had to quickly adjust to 15-20 foot waves. One day the swells even got to be 30+ feet, with wind gusts of 50 knots! While the Southern Ocean is notorious for being rough, we were sailing into a large low-pressure system.

After crossing the Antarctic Circle (66.3° S), we not only woke up to calm seas – but also giant icebergs the size of skyscrapers!

Our first iceberg

Once we saw the first signs of ice, we began to adjust to our work shifts. To fit in as much science as possible, we operate 24 hours a day. In the science party, we work 12 hours on and 12 hours off. I am part of the night shift and on the clock from midnight to noon. At first, the adjustment was hard, but it got easier after the sun started staying up almost 24/7. We stayed awake by watching movies in the lounge, trying new card games, playing ping pong in the helicopter hanger, and exploring the Palmer. After a night or two, we started transitioning into “work” mode, with lots of coffee!

Moving closer to our destination, the icebergs faded away as we reached patches of floating sea ice. Since it’s summer in the Southern Hemisphere, the ice has been melting and we haven’t had to do any “hardcore” ice breaking yet.

Moving through sea ice and into the Ross Sea

We did see a few whales and dolphins during our transit across the Southern Ocean, but nothing compared to the wildlife we saw once we reached the pack ice! Our group was most excited to see some penguins and, luckily, they stand out from the white backdrop of the ice. So far, we have seen Adelie and Emperor Penguins off in the distance. We have also seen many crabeater seals lounging on sea ice.

Soon, we’ll reach our first study site and start science operations!

-Emily Kaiser

Some critters from my iphone camera