Top marine predators, such as seabirds are a important component of the Southern Ocean ecosystem.
A black-browed Albatross observed during our at-sea surveys along the LTER sampling grid. (Photo by K.B. Gorman)
This includes species with extremely high biomass or critical conservation interest such as the Adelie penguin or the southern giant petrel. These animals occupy specific ecological niches and depend on ocean productivity for their own survival as well as for raising their young. Hi, I’m Bill Fraser and my team and I conduct at-sea observations of seabirds during the cruise to identify the importance of foraging locations.
One of the highlights of our work on the LTER cruise is the 5-day field camp at Avian Island, just off the southern tip of Adelaide Island in Marguerite Bay. Here, we are interested in aspects of the breeding and foraging ecology of these species in comparison with lower latitude nesting areas around the Palmer Station. We try to assess the variation between populations that are subject to different environmental conditions from
Sunset over Avian Island showing the large numbers of nesting Adelie penguins. (Photo by K.B. Gorman)
climate warming. We typically census nesting Adelie penguins, southern giant petrels and blue-eyed shags, as well as deploy satellite Platform Terminal Transmitters (PTT). These PTT’s are instruments we attach to adult Adelie penguins to track foraging areas used by the adults to obtain what nutrients they use to feed chicks.
A PTT transmitter attached to an adult Adelie penguin with chicks at Avian Island. (Photo by K.B. Gorman)
This year was exceptional in that we explored the presence of nesting Adelie penguins at Charcot Island, an area even farther south than Avian Island that is still subject to the presence of summer sea-ice. We were able to confirm the presence of Adelies in the area, and despite the moderate sea-ice able to access the colony to attach PTT’s to nesting adults. This is the most southern population of Adelie
Charcot Island in sea-ice where we searched for nesting Adelie penguins. (Photo by K.B. Gorman)
penguins our group has worked with to date. The data obtained from Charcot Island will lend an unprecedented perspective on the foraging ecology of this sea-ice dependent species.
This is a view of Charcot Island from about 4 miles away through the sea ice, with tabular bergs in front of the island. (Photo by Alex Kahl)
We are at Charcot Island, 69 deg 48 min South, 75 deg 30 min West. This Island is 30 miles long and 25 miles wide. It is the farthest south the LM Gould has ever been! As you know we have come this far south in search of a place that is cold enough for sea ice to be present during this summer season. But also, because we are searching for a poorly-documented Adelie penguin colony here. Yesterday we entered sea ice around noon and then we were able to get close enough to the island by Zodiac to visually and photographically verify the presence of penguins.
Tabular Iceberg near Charcot Island (Photo by: Alex Kahl)
These first two pictures are calved off ice shelves – hence their very regular shapes and height. Subsequently, the larger part of the berg that is underwater, gets melted and eroded by wave action and the bergs overturn and assume fantastic shapes. The many tabular bergs near Charcot Island may be remnants of the Wilkins Ice Shelf, parts of which disintegrated in early 2008.
Tabular Iceberg and the LMG taken from our zodiac (photo by Alex Kahl
Take a closer look at the tabular ice berg and see if you notice the coloration. The sea ice is colored this way from specially -adapted organisms like sea ice diatoms – a phytoplankton that live in brine channels in the ice. Growth of these algae in the spring colors the ice tan or brown. The color is not dirt but rather a rich biological community.
Diatoms in the Ice (Photo by Maggie Waldron)
One of our gliders deployed from our zodiacs on January 19th and is now swimming toward Adelaide Island. The data from the glider will survey the area where penguins like to feed and then provide us information on the biological and physical conditions of the water there. You can follow the gliders progress on the web (RUCool). You will see the Palmer LTER glider called RU05 at this link and find out more about the information it is collecting.
Gliders combined with feedback from the moorings will provide us a foundation for an ocean observing network that gives scientists, like me, a view of the Southern Ocean near the Western Antarctic Peninsula 365 days a year. This will be critical to understanding how changes in climate will influence the biology of the water surrounding Western Antarctic Peninsula.
Data Provided by John Kerfoot
included an example of some data collected during this January 19th deployment. The colors show the magnitude of what variables we are measuring. In this case I’ve shared temperature data and phytoplankton data collected by the glider. The bottom panel shows the ocean temperature recorded by the glider as it travels (distance) at different depths (meters). How cold is the water at depth? The top panel shows a map of phytoplankton, which if you notice is growing well in the upper ocean layers. Why do you think so? Well, this is where sunlight is capable of driving photosysnthesis (the food making process for plants). The white gaps in the data is where the glider has gone to the surface and is making a cell phone call to New jersey. (Data graphic provided by John Kerfoot)
Hi, my name is Oscar Schofield. I am using undersea gliders (remote control robots) to measure basic physical and biological properties in the ocean during this cruise. The ‘ Slocum Webb glider is the one we are using today. It was names after Joshua Slocum who was the first person to sail around the world’s oceans alone.
The Webb glider being deployed from a zodiac on January 19th, 2009 (Photo courtesy Elizabeth Leonardis)
We have added these robots to Palmer’s oceanographic field studies because they have many advantages over working from a ship. They can be deployed in the water for several months at a time depending on the type of batteries we use. They are mobile and we can change their sampling patterns as the ocean changes. But better yet, they do not get sea sick which allows us to collect data during harsh conditions that often are unsuitable for us working from a back of a ship. The glider does not have a propeller. Instead, it moves by changing its buoyancy. The robot is carefully balanced so that it maintains a neutral buoyancy, changing its weight by sucking in a small amount of sea water to make it float or sink. It is equipped with wings, which make it move forward as it sinks. When it reaches its desired depth, it pushes the sea water out of its ballast, making the glider lighter than water which forces it to float upwards in a forward direction. This is very efficient and allows the glider to “fly” around for months at a time.
A Webb glider resurfacing. In the background is the Lawrence M. Gould. (Photo courtesy of Elizabeth Leonardis)
Every so often, the glider stops at the surface and makes a global cell phone call back to my lab at Rutgers University. During this time scientists in New Jersey download data and adjust where the glider is moving. The glider carries with it several sensors. One is the Conductivity-Temperature-Depth (CTD) sensor. Another is a sensor which measures the optical properties in the ocean water, which scientists can relate to the amount of phytoplankton and particles present.
Palmer LTER Annual Cruise 17:LMG 901 18 January 2009
Oceanographic stations that are sampled annually as part of the Palmer LTER research set out to document geographic distribution and changes in environmental variables like physical structure of the ocean water column, nutrients, dissolved CO2, plant photosynthesis, krill abundance, and penguin breeding success. Individual locations where samples are collected are referred to as oceanographic stations. Oceanographers name such station to facilitate future identification. Our second major station (~ 67 degree 46S, 68 degree 51W) commenced January 20th. Sticking with tradition, we have decided to dedicate this station to President Obama and his administration in celebration of the Inauguration. It is this administration who are dedicated to bringing ocean sciences and climate change research to the public’s attention. Over the course of three days, intensive sampling will occur, uncovering the linkages among ocean mixing and currents, biological processes and carbon cycling. We will be investigating the processes that result in the storage of atmospheric CO2 in the water column produced through marine biological activity (The Biological Pump). Meanwhile, some of the researchers will be camped on nearby Avian Island, conducting census of penguins and other seabirds that forage in the Obama region.
In this blog entry we would like to show how the moorings are deployed in the water. In the first photo one of the Raytheon technicians (Dan Powers; black hard hat) is about to put the surface-most float in the water (the white ball).
Beginning deployment of mooring.
There is a temperature sensor attached to the string immediately below it (the white cylinder hanging just above his foot). At the bottom of the mooring lies the anchor which is connected to the crane hook next to Jamee Johnson in the red hat. Once the anchors are put in and the entire mooring line fed into the ocean, the anchors will sink to the bottom of the sea-floor. That’s me, Doug, watching the deployment (in the white hat).
If you’re wondering just how large these moorings are, how about this?
The strings from each mooring are longer than the Empire State Building is high. We’ve included an illustration so it’s easier for you to visualize. In this second photograph below, the string is being fed into the water, and eventually the crane will release the anchors. The floats will keep the string stretched to the surface. If you look at the illustration you will notice that
Crew feeding the line into the ocean. The crane operator waiting to release anchor.
there are several temperature sensors (17 on this mooring) placed at different depth intervals. These record temperature in the water. The temperature is measured every 20 minutes until we come back next year , pull the moorings up , pull all of the stored temperature measurements off onto a computer, put new batteries in and send the mooring back in for another year. The temperature is represented by colors. The warmest temperature is red, the coldest is blue. We want to measure the red water to establish the amount of heat the ocean provides, and then see how it changes as the heat is lost to the air and how much is lost due to glaciers melting.
Researchers believe that water exchange in the Southern Ocean is one of the primary physical processes influencing the Western
Map of the Antarctic Peninsula showing the core study region (inner box), the entire PAL survey region (larger box) and the extended regional grid based on satellite studies. Lines are space 100 km apart and station spacing is 20km. POOZ: Permanent Open Ocean Zone (no sea ice). SACCF: Southern Antarctic Circumpolar Front (dashed line) Ducklow et al (2007) and Smith et al (2008).
Antarctic Peninsula’s marine ecosystem. The abundance and distribution of plants and animals are affected by the surrounding water conditions. For instance, situating these moorings near penguin colonies can help us monitor food web patterns. Studying these water patterns can help us understand the magnitude of water exchange with the atmosphere and then we are able to identify its driving forces.
In the polar regions the ocean is warmer than the air, and the water below the surface is warmer than freezing. This warm water serves as a source of heat and it passes from the water into the air (warming the Antarctic air) influencing the climate but more importantly melting glacial ice. When the glaciers melt the water runs into the ocean and can raise sea level around the world. My job as a physical oceanographer is to determine how much heat from the ocean passes into the air and melts glacial ice. One way I do this is by placing moorings in the ocean. These long moorings (ropes) stretch from the sea floor to the sea surface by using floats and anchors. On this particular cruise project, I have five (5) such moorings. The mooring strings are longer than the Empire Stat Building is high. When the anchors finally go in, the entire moorings sinks, but the floats keep the string stretched to the surface.
Seaman and Winch operaor Guillermo Cifuentes delivers the CTD through the Baltic Room door.
Marine Tech Chance Miller views the rosette at the surface and prepares to retrieve the CTD package.
A large part of our sampling is accomplished by using a CTD-Rosette water sampler. It consists of an electronic sensor package and 24 sampling bottles. The sensors report on the salinity, temperature, and other variables at 1-meter depth intervals in the water column. The bottles can be tripped to take water at any depth. The scientists collect the water for analysis in the shipboard labs or sometimes bring the water back to their labs at home for further analysis. The CTD is deployed through a large enclosed space on the ship named the Baltic Room.
Microbe team members (from top) Lara Gates, Mags Waldron, Zena Cardman and Mark Rasmussen collect water from the rosette bottles.
Ship electronics Technicians (ET) Mike Coons (left) and Chief Scientist Doug Martinson discuss the CTD output on the monitor in the upper Baltic Room.
Marine Technician Chance Miller (right) and zooplankton team member Kate Ruck (left) deploy the zooplankton net. (photo by D. Steinberg)
Zooplankton are small animals that drift with the ocean currents. We catch zooplankton by towing large nets behind the ship. In the Southern Ocean where we are working, small, shrimp-like zooplankton called krill are extremely abundant and very important food for penguins, whales, and seals.
Close-up of Antarctic krill from catch showing green gut filled with phytoplankton (microscopic plants) that it has recently eaten. (photo by Andrew McDonnell)
Krill themselves feed on microscopic plants called phytoplankton (studied by other members of our group). The catch is brought on board and sorted in the laboratory. We catch many other different kinds of zooplankton too, including gelatinous salps which like krill can also occur in large numbers.
Zooplankton team members (Kate Ruck, Lori Price, and Glaucia Fragoso) sort the catch in the ship laboratory. (photo by D. Steinberg)
Zooplankton team members in the aquarium room with catch of krill and other zooplankton (left to right - Kate Ruck, Joe ope, Glaucia Fragoso, Lori Price, Miram Gleiber; back - Dr. Debbie Steinberg) Photo by Rick Smaniotto