Science Recap: More than halfway through our sampling!

Our sampling and deployments have been moving along rapidly! Suddenly we are over halfway through the science operations for our cruise. Here are some highlights from recent operations!

We’ve seen some amazing weather in Andvord Bay with clear blue sky, warm shining sun, and glassy calm water.

Of course most of the days have had temps hovering around or below freezing, snow or rain, and overcast skies proving to us that the weather of the West Antarctic Peninsula is highly variable. Sea ice and icebergs move quickly and conditions can change quite rapidly. We’ve seen katabatic winds suddenly intensify to over 70 knots (hurricane force)! This means that we must constantly be aware of ice conditions and change our sampling plan if there is too much ice to safely conduct an operation. The West Antarctic Peninsula is known for having variable weather as westerly winds bring warm, moist air from the Pacific Ocean to meet dry, cold air masses moving over the continent. This is also what causes major differences in climate between the West Antarctic Peninsula and other portions of the Antarctic continent, further emphasizing the interest in this region in the face of global climate change.

The ice cooperated with us long enough to deploy all of the physical oceanography moorings, weather stations and glacier cameras. The last camera was installed recently in the inner basin of Andvord Bay. The physical oceanography/glaciology team donned climbing gear and zipped away in the Zodiac to assemble this camera on a rocky outcrop facing the termini of a two massive glaciers at one head of Andvord Bay.

AWS

The physical oceanography/glaciology team makes their way to the site of an automated weather station and glacier camera. Can you spot them?! Photo Credit: Eric Vetter.

This camera will take photographs of the glaciers to assess calving rates, snow cover and melting rates. These parameters will help constrain the ice flux into the fjord and the overall movements of the glaciers. This affects the amount of freshwater and sediment entering the fjord, which in turn influences the productivity (bringing the micronutrient iron) and animals on the seafloor. The ice hasn’t always been on our side, however. We discovered a shallow mooring that we deployed 2 weeks five kilometers down fjord – the entire mooring (including 1200 lbs of railroad wheels) had been dragged >5 km by an iceberg and released in shallower water!

The benthic ecology team assembled a time-lapse camera mooring which will be located in the middle basin of the fjord. This camera is designed to take images of the seafloor four times daily for the next four months; we will then recover the camera, swap batteries and redeploy it for the remainder of the project.

The images will reveal rates of animal activities (e.g. moving, feeding) and responses to seasonal food inputs such as sinking krill carcasses. The camera mooring was deployed smoothly and safely. 15 minutes later voices came over the radio saying there was a mooring mast that just rose to the surface nearby unexpectedly. The radio beacon identified it as the camera mooring which had just been deployed.

mooring

The camera tripod mooring at the surface. Photo credit: Amanda Ziegler.

The team and ship’s crew quickly put a recovery plan together. The ship positioned alongside the mooring which was grappled and carried down to the stern to be lifted onto the ship. Once onboard it was clear that one of the acoustic releases had failed, but how it had failed was less clear. The weight which had been attached to the releases was obviously gone but the release which dropped the weight was still in the locked position. How could this be?! The team removed the release, opened it up and discovered that it had leaked. The pressure experienced by the release during its descent had forced water into the housing and shorted the electronics, causing it to release the weight without receiving the acoustic signal. Not what we expected! It was a great lesson in working with moorings and a reminder of the risk we take with our equipment to get the data we need. The team later mounted a new release and redeployed the mooring; it is now remains on the seafloor happily collecting data!

Written by Amanda Ziegler.

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Sampling Excursions to Neko Harbor and Installing a Weather Station

The FjordEco project is more than an interdisciplinary oceanographic survey. The field plan also incorporates glaciology and meteorology into a comprehensive biological and physical oceanographic program. Key components of this complementary science are the installation of weather stations and glacier cameras (later detailed by Martin Truffer) on the shores surrounding Andvord Bay. We have also used these opportunities to expand the biological sampling to include sea ice algae and benthic food sources. Shore excursions are special treats because they allow us to step onto the Antarctic continent, unlike Palmer Station that is located on Anvers Island. Not only is Neko Harbor a site of our first weather station and samples of opportunity it is also a popular destination for the cruise ships as it is home to a nesting population of Gentoo penguins.

Installation of the weather station as well as sample collecting required several trips to Neko Harbor. To avoid introducing invasive organisms, we are required to scrub and wash our boots prior to boarding the Zodiac as a preventative measure. A dedicated team for the weather station unloaded roughly a thousand pounds of gear to shore. The majority of this was battery packs for the weather station that we hope will provide temperature, wind speed and direction, snow depth and barometric pressure using a satellite link over the next 2 years. Additional science crews went to collect algae and penguin feces for stable isotope analysis. Conditions are always changing here and some groups had light snow one day followed by freezing winds and ice, while my group had sun and scattered clouds.

The three scientific teams had very different goals to accomplish. The weather station team cleared snow and ice to affix the platform, lugged equipment up the hill, assembled the station and ensured the gear was sampling properly and transmitting the data to a lab in Wisconsin. The biological team combed the shoreline for macroalgae, kelp and intertidal invertebrates that might be a source of food for the benthic communities, and also collected the green and red hued penguin feces. The final team of marine technicians from the Gould watched for a change in weather and the ice. Regardless of your assigned duty, it was all too easy to become enthralled with the comings and goings of the Gentoo penguins that inhabited the rocky outcrops that would soon become a nursery.

The characteristic waddle of the penguin made for slow but steady travel over the snow, but if that became too tiresome they would flop down on their bellies and propel themselves with a push of the feet. Throaty calls reverberated off the glaciers as penguins announced important news intelligible only to the other rookery inhabitants. Sometimes they were seen marching with military precision while others wandered aimless and alone. As charming as the land movements were, it was the transition between land and sea that was most entertaining. Penguins coming ashore would surface amid the small chunks of ice that lined the shore’s edge, and for a half meter and 3 seconds, perform the oddest of stumbling movements to make the transition to land. From land to sea, however, all it took was a brief step and a short hop and the Gentoo glided away underwater sleeker than any human could ever hope to be.

All too soon our alert marine techs warned us about a change in the wind and with haste we made for the Zodiac so that our day trip did not become an overnight campout. Ice was quickly moving in our direction down the fjord and all other projects had to be curtailed so that we could make our way through the narrowing passage into open water. We took up positions ready to fend off chunks of ice that threatened to impede our progress and our pilot deftly moved us through the ice floes into the bay and back towards our floating home. There may be more opportunities to go ashore as the science continues but the welcome opportunity to stretch our legs came at a perfect time. Appropriately, our wonderful excursion climaxed as we were halfway to the ship. A single humpback whale blew twice and dove beneath the waves with a flip of its fluke casually entering the indigo depths; easily penetrating the productive ecosystem of Andvord Bay that for us is still a mystery to solve.

Written by Clifton Nunnally.

Neko Harbor

It’s no secret that Andvord Bay is one of the most spectacular places on the planet. Sun glittering over the ice and snow, massive icebergs drifting just offshore, the sound of penguins calling to their mates. Since our arrival in the fjord, we have seen tourist cruise ships almost every day! One of the most heavily visited locations is a penguin rookery in Andvord Bay called Neko Harbor. This site must see thousands of visitors every year and is the nesting ground for hundreds of Gentoo penguins. But we weren’t here to see penguins, we were here to do science and Neko Harbor is an ideal location for collecting long-term weather data and images of nearby glaciers.

The physical oceanography team were the first of the science party to set foot on the Antarctic continent at Neko Harbor. There they scouted a suitable location for an Automated Weather Station (AWS) which relays wind, temperature, atmospheric pressure data and more for the duration of our study as well as a camera, which will take photographs of the nearby glaciers. These data will help inform other aspects of our project such as the glacial movement and melting rates, and the physical oceanography moorings. In addition to the AWS and glacier camera at Neko Harbor, there is also an AWS to be set up in the Gerlache Strait between Anvers Island and Andvord Bay and another glacier camera within the innermost portion of the fjord. As these instruments must be working for several months, part of the team returned to the AWS again to ensure that it is working properly relaying data to shore.

While ashore at Neko Harbor, members of the benthic ecology team made several collections. They were targeting mainly macroalgae and penguin poop….yes, penguin poop. Oh the glamorous lives we lead as scientists! These samples will determine the contributions of various food sources to the animals living on the seafloor in the fjord through stable isotope and biomarker analyses. By collecting samples of as many food sources as possible we will be able to better constrain animal diets and see how nutrients flow through the food web. Of particular interest is the role of Antarctic krill, a keystone species in this ecosystem.

Neko Harbor has been a great sampling location and site for our long-term weather stations and glacier camera, but we don’t need much more of a reason to want to stop here than the hundreds of charismatic Gentoos running about the shore. Hey, maybe we were here for the penguins after all!

Written by Amanda Ziegler.

Science operations in Andvord Bay

We slowly made our way into the narrow mouth of Andvord Bay, guarded by steep mountains on either side that are covered in thick snow and glacial ice. There are a huge number of massive glaciers along the sides and at the head of the fjord. Each of these sheds large chunks of ice into the ocean which then slowly drift about the fjord. We make our way around the ice while Humpback whales spout in the distance. The sight is breathtaking; certainly rivaling some of the most beautiful places on earth. Though the ship is loud, there is a peaceful quiet outside as one looks around surrounded by towering peaks and blankets of soft snow. Working hard for the next few weeks will not be half bad with this amazing sight right outside!

Sampling in the fjord has been productive so far! One of the first operations was towing the Acrobat system; an instrument which measures water properties such as temperature, salinity and fluorescence. Right away there were interesting results that were investigated further with targeted CTD (conductivity, temperature depth) surveys across the fjord sill. We will continue targeted sampling to further resolve some of the possible patterns we are seeing in our data.

We also conducted the first two Blake trawls in the middle basin of Andvord Bay. These trawls allow us to collect animals living on the surface of the seafloor and identify the animals we are seeing in our images of the bottom. The first was small as the net fouled on its floats during the descent, but it still provided us with interesting animals. Of note were two stalked sea pens, numerous polychaete worms, ice fish and sea stars. Our second trawl, however, was quite the sight. As it was hauled up on deck, the benthic ecology team realized we were in for a treat. The net came up full of animals and soupy mud. It was quickly oozing all over the deck much to the disgust of the physical oceanography team who would be working there after us. When the net was opened a flood of mud came gushing onto the deck; our playground for the next 8 hours! We even caught one big boulder! There were sea stars, sponges, jellies, octopuses, fish and worms of all kinds! We sorted the bounty of animals for several hours painstakingly photographing each one and deciding what animals were destined for what analyses. At the end of the mayhem we had samples for stable isotopes, fatty acids, genetics, morphology and much more. It will be exciting to see what we catch in the next trawl!

Written by Amanda Ziegler.