At Site U1359, Hole U1359B,
Position: 64º 54.25’S, 143º 57.63’E
Water Depth: 3100 meters

ABOARD THE JOIDES RESOLUTION, OFF THE COAST OF WILKES LAND, ANTARCTICA– Hi everyone! As we approach our 2000th meter of drilling I thought I would change things up a bit with this blog and send along some photos of the birds we’ve been seeing. The Southern Ocean is the coldest and windiest on Earth, but it also one of the most bountiful. During the 3 or 4 months of long days and short nights, the “farm” operates 24/7. The plants that live in the sunlit waters here are nourished by nutrients that mix upwards from the deep sea and go into overdrive building their cells. It’s easier for nutrients to mix upwards into the sunlit upper waters here simply because the water column is “isothermal”. This means that we see very little variation in the temperature of the sea between the surface and the bottom waters over 3000 meters below us. It is all close to 0 degrees Celsius. This means that it takes very little energy to move dense cold water from the deep upwards because the surface water is also cold and is almost as dense. So the plants have everything they need. The wind and circulation drive the mixing, which brings in the nutrients, and the sun keeps the farm growing nearly 24 hours every day. Plants (mostly single-celled protists called diatoms) grow fast and the small plankton that eat the diatoms grow fast as well. Which brings us to the birds…..

Albatrosses in a storm.

Our ship is constantly surrounded by Albatrosses, Petrels, and Skuas. Sometimes we see more than 100 birds surrounding the ship. They swoop and dive, looking for food in the water, either plankton or small fish, or perhaps they think we are land. We haven’t seen one try to rest on the ship yet. In fact the Albatrosses rarely set down at any time. They fly 1000’s of miles from their breeding colonies and are at sea for months and even years at a time.

Here are some photos of the seabirds we’ve seen so far.

These first two are of Black-browed Albatrosses (Thalassarche melanophrys). They live throughout the Southern Ocean and breed in places like the Falkland Islands and South Georgia. They can live to be as old as 70 years and spend long periods of time at sea, even encircling the globe. They feed on krill and small fish – that in turn eat diatoms and smaller plankton.

Black Browed Albatross

Black Browed Albatross

The most common bird we saw at our drill sites close to the Antarctic continent were the Pintados, also known as Cape Petrels (Daption capense capense). The name Pintado comes from the Spanish word for “painted”. They live throughout the Southern Ocean, mainly eating krill, especially on and near the continental shelf of Antarctica in summer. A 2009 census estimates there are over 2 million Cape Petrels alive today.

Cape Petrel (Pintado)

Cape Petrel (Pintado)

Cape Petrel (Pintado)

We’ve also been surrounded the past few days by Southern Giant Petrels (Macronectes giganteus). These are indeed big birds….females can weigh up to 18 pounds. Sometimes they are called “stinkers” as they can spit a foul-smelling liquid at predators or when they are perturbed.

Southern Giant Petrel

Southern Giant Petrel

I hope you enjoy these photos! I’ll get back to our science and progress next time and I’ll try to knock out least one more video blog. We are VERY busy with work here now but it all very exciting.

The three types of killer whales. From R. Pitman, P. Ensor, J. Cetacean Res Manage 5(2):2003.

Ross Sea killer whales appear in the McMurdo Sound area and the southern Ross Sea, in early December and ply various fast ice edges (ice attached to the land), which as the season progresses recede further and further south toward the continent. They also apparently forage under or along the edge of the Ross Ice Shelf by Cape Crozier on the other side of Ross Island. These whales feed on fish that live under the fast ice and as the ice recedes the whales are able to exploit more and more feeding territory. Sightings of these whales, from land, helicopters and ships have been carried out through the years, most recently from the Cape Crozier and Cape Royds penguin colonies on Ross Island, where it has been noticed that the presence of whales (including minke whales) follows a shift in the diet of the penguins.

Killer whales foraging in a sea ice crack.

In 2005 the ratio of C to B killer whales was 50-1, but over the next few years it steadily dropped to 16-1 by 2008. As the observed numbers of B whales (seal eaters) did not change during this time, the altered ratio was due to the decrease in Ross Sea killer whales. During the years of these observations another important series of events was taking place.

Although commercial fishing of the Antarctic toothfish (sold as “Chilean sea bass”) in the Ross Sea began in 1996, it was expanded in 2004 from 9 to 22 fishing vessels; not surprisingly that same year the catch reached its allowed limit of 3500 tones. These boats target the largest adult toothfish, which is the same size those taken by the whales. Toothfish are a slow growing species which do not reach maturity until 16 years old. Many of these fish taken in the fishery were over 25 years old, some older.

Antarctic toothfish.

Since 2004, the commercial catch has remained steady year by year. Catch and release efforts of toothfish by scientists in McMurdo Sound remained steady from the years 1974 to 2000, but dropped 50% in 2001 a few years after the commercial fishing began and then to 4% in 2007, only 3 years after the peak commercial catches began. It would appear that the drop in Ross Sea killer whale numbers is related to the increase in the commercial fishing of the toothfish.

Are there any other animals that would be affected by the reduction in toothfish numbers?

Weddell seals also take toothfish as a primary food source and their numbers have not decreased in McMurdo Sound, though trends elsewhere along Victoria Land are unknown. Seals are able to dive deeper and stay under longer than the whales and therefore able to catch the fish which are safe from the whales. Seals therefore not only forage where the whales forage, but also in areas the whales can not reach, places covered with extensive fast ice where small cracks provide breathing holes. Seals also eat silverfish. It is thought that whales also eat silverfish but there are no confirmed sightings for this. The whales therefore may be more sensitive to changes in toothfish availability. If the toothfish industry continues to extract the current yearly numbers, it is predicted these creatures will decline more rapidly.

For more information about the Ross Sea, the toothfish industry and how it is affecting penguins, whales and seals go to The Last Ocean.

For some time it was thought that Weddell seals did not eat the toothfish and therefore would not be affected by the reduction of these fish in the ocean. The fishing industry has pushed to increase catch limits based on this assumption. We’re learning, though, that this is not true by indirect means.

One way researchers determine what an animal eats is by sorting through their scats (body waste). Indigestible parts pass through the body of seals and whales and can be identified. In the case of fish, the ear bones, or otoliths, are used to determine not only what species of fish are eaten, but how old and large they are. Toothfish otoliths have not been found in seal waste. But recently we’ve learned why.

Antarctic Toothfish ear bone (otolith).

As is the case with many discoveries chance plays a large part. While out on a diving expedition one researcher discovered the heads of many toothfish near a crack in the ice. The only predators in the area are seals, so these heads must be the remains of their meal. No wonder there are no otoliths in the seal waste, they don’t eat the heads! By observing seals in holes drilled through the ice for scuba access, it has been observed that seals remove the heads so this information was already known. But many people still doubt the implications of this or contend that it is a ‘local’ phenomenon. Finding these heads, in the company of seal holes, was another clear indication that this belief is wrong. Retrieving these heads would also mean that scientists could remove the ear bones (otoliths) and determine the age of the fish as well as where the fish grew up (one of the many mysteries about toothfish that remains unsolved).

The crack, where seals come to find toothfish hiding under the ice.

The helicopter landed us in this remote place on the McMurdo ice shelf.

So off we go. First a helicopter ride to the place where the fish heads were first found, and then a 10 km walk over and around the rough terrain along the crack in search of other evidence. All in all the remains of 30 fish were found, and 20 heads were brought back to the lab to extract the otoliths.

Antarctic toothfish heads, the remains of a Weddell seal feast.

Searching for Antarctic Toothfish heads on the McMurdo Ice Shelf crack.

Bagging Antarctic Toothfish heads.

As it turned out, most of the heads had become mummified, i.e. freeze-dried, and acidic action in the flesh during the process of decomposition in many cases dissolved the otoliths. There were just little ‘puffs’ of white stuff where the otoliths should have been. Skuas had eaten the otoliths in other of the heads. But, we did find otoliths in 6 heads, and these will be tested and analyzed in a lab in the US. Providing evidence to fishery biologists that toothfish are an important food source for seals will help the argument to limit the commercial catch.

Learn more about Antarctica toothfish and conserving the Ross Sea for all marine organisms by visiting The Last Ocean.

ABOARD THE RVIB N. B. PALMER, ON THE SOUTHERN OCEAN– After a four day trek looking for other icebergs we might want to study, we came back to continue studying iceberg C18A. Iceberg diversity and how it affects surrounding ecosystem is one of our goals. If the icebergs are delivering nutrients, one of our main hypotheses, we expect to see big changes when the iceberg is traveling in nutrient poor waters. The trick turned out to be how to find these nutrient-poor waters in the Weddell Sea. Looking at published nutrient values it seemed that the central Weddell Sea, far from the coast, could be a good possibility. From satellite pictures we speculated that B15L, an iceberg from the Ross Ice Shelf, could be in such waters.

As we arrived at 65º 28.362’ S, 40º 56.856’ W, B15L was surrounded by the biggest phytoplankton bloom we have seen on this cruise. Instead of half a milligram of chlorophyll a per liter we encountered ten! These waters did not seem poor in nutrients at all. The iceberg was large, tabular and somewhat more square than C18A but of similar size and characteristics. It would have been perfect for our studies. After taking a first look at the iceberg, many pictures, samples for phytoplankton and nutrients, we decided these conditions were not conducive to answering our questions. The ice edge was less than 100 nautical miles to the south; B15L was trapped in what is known an ice-edge bloom, one of the best studied high productive areas in high latitude oceans.

B15L as seen close to the ice edge in the central Weddell Sea. This iceberg has traveled from the Ross Ice Shelf half a continent away.

The ice edge bloom was dominated by diatoms. A high diversity showed many new species not sampled so far. Several Chaetoceros spp. were very characteristic: chain-forming species with interlocking spines.

Dominant diatoms at the ice-edge bloom close to B15L: Chaetoceros spp.

How best to continue our studies? Keep looking for a new iceberg in the middle of the Weddell Sea or go back to where satellite images show icebergs abound, the Iceberg Alley? We decided for the latter. In another 24 hours we were back to the western Weddell Sea. We decided to study C18A for a few more days; there were many unanswered questions still. So we are glad to have a second opportunity. A few things are different this time around. C18A had kept moving towards the NE and its position is now more along an East-West axis than a North-South one. We will be here for the next 3 days and sampling has already started.

Hassan is part of the glaciology team for the McMurdo Dry Valleys Long Term Ecological Research site (LTER for short), which is led by Andrew Fountain of Portland State. The LTER Network includes 26 sites mostly in the US, and includes ecosystems from the poles to the tropics. Scientists study the areas from many angles, combining their research to give a broad view of how ecosystems work. (Video by Lisa Strong-Aufhauser)

Canada Glacier with frozen Lake Hoare in the background.

Summer melting from the Canada Glacier feeds a stream that flows into Lake Hoare.

The Dry Valleys are dry because very little snow falls here, the average water content is less than a centimeter. Yet a fully functioning ecosystem exists here, in the ice-covered lakes and the soils of the valley floor. Even though the ecosystem is all but invisible to the naked eye, it still has a basic food web: primary producers (mats of moss and algae in the lakes, bacteria, yeast, fungi and other microbial life in the soils ), grazers (microscopic invertebrates called rotifers and tardigrades), with the top of the food chain consisting of tiny nematode worms. Curiously, there are no known predators in the Dry Valleys soils. These valleys constitute a Long-Range Ecological Research (LTER) study site and represent what scientists believe might be a model for life on Mars if it exists.

Lisa Strong on a hike with Canada Glacier behind her.

The origins of Seuss Glacier pouring through a mountain pass in the Dry Valleys.

Lisa and I went for a walk up the Taylor Valley to see whether we could uncover any evidence of life and saw little, except for a couple of long-dead seal mummies (why they traveled so far from the sea ice is anyone’s guess) and some algae-covered rocks and brown floating scum, looking for all the world like whipped chocolate mousse. We did see plenty of wind-scoured rocks and glaciers pouring through gaps in the surrounding mountains.

Bones and skin of a seal mummy that perished hundreds or thousands of years ago.

Biological scum on Lake Chad.

For easier walking, I tried to cross the moat between land and solid (white) lake ice. What I thought was thick ice wasn’t and I broke through up to my knees for my own version of the polar plunge. After changing into dry pants and socks, we continued on our walk but the only macroscopic life we saw was a lone skua winging up the valley.

Mary after breaking through lake ice.

I knew I needed to dig deeper, so I’ll turn to the LTER scientists studying the different parts of this ecosystem from the glaciers that feed life-giving water to the lakes and soils, to the ice-covered lake waters that support microbial life, to the soils that provide habitat to bacteria, yeast and fungi, and invertebrate creatures that make up “charasmatic megafauna” of the Dry Valleys. Look for upcoming video interviews with these LTER scientists.

Glaciologist Hassan Basagic of Portland State University explaining the dynamic of Canada Glacier to Lisa.

Buckled ice: Sea ice meets ice shelf off McMurdo Station.

The vastness of this place is shocking. It continues like a sparkling white desert. Yet, it is different from the deserts of the world in one profound way; the horizon is lifeless. Unlike a desert, there is no lone dry bush or defiant cactus. There are no crickets, no beetles, and no fluttering butterflies.

As a scientist it gives me pause. Our web of life has existed for billions of generations, yielding billions of mutations. At least hundreds of millions of chances for one mutation to get it right and one defiant plant or insect to stake claim to the ice of this vast continent. But, nothing thrives here in this ecosystem seemingly without competition or predators. Life as we know it cringes from this cold. Scientists know the waters below the ice are rich with bio-diversity because temperatures are less extreme. Still, I am struck by the profound lack of life atop the ice. Is the window for existence so minute? Is our biosphere confined even within the pristine conditions of our miraculous planet?

Ice road leaving McMurdo.

Then it strikes me, as I struggle for a photo of a mammoth yellow tractor cutting an ice road, “I am here. I live atop the ice.” We are here, humans. We are the result of millions of mutations comprising a complex balance allowing for our survival in such a place. We construct buildings, cut roads, and engineer machinery fit for this environment. As I approach the small scientific town of McMurdo perched on the permafrost below a cross-bearing hill, I realize the magnitude of this accomplishment. Like the Pyramids of Egypt, Sistine Chapel, Golden Gate Bridge, and the Empire State Building, McMurdo Station exists as a monument to the human spirit. It illustrates that in all efforts to explore and learn, the human race is at its best.

View of McMurdo Station from Observation Hill.

Antarctic krill, Euphausia superba, is the largest krill species.

Adélie penguin nesting areas on Avian Island, stained red due to the penguins’ highly krill-based diet.

Dip a net into coastal Antarctic waters and you’re likely to pull up more than a few pinky-sized shrimplike crustaceans. These are krill, and if they look like small-time players in the game of life, it only goes to show exactly how deceiving looks can be.

The Antarctic food web is the simplest on the planet, and krill are at its hub. An estimated 500 million tons of krill live in the Southern Ocean, making this the most abundant animal in the entire world. Krill are such a universal food in Antarctica that for almost every animal that lives here, a “three degrees of krill” rule applies: You are krill, or you eat krill, or your food eats krill.

Whales, seals, penguins, albatross, petrels, fish, squid—every animal species living in Antarctica depends directly or indirectly on krill for survival. This heavy reliance on a single species makes the Antarctic ecosystem an unusually fragile one, particularly since many animals—including baleen whales such as the humpback, fin, minke, and blue whales—eat krill almost exclusively.

Krill, in turn, filter-feed on the abundant phytoplankton in the open ocean. In winter, they also gorge themselves on the ice algae that grow on the underside of the pack ice. A single krill can scrape clear the algae from a square-foot (.09 m²) patch of ice in ten minutes, zigging and zagging back and forth lawn mower–style.

Corethron, a type of phytoplankton, highly magnified under the microscope.

This image, taken by a remote operated underwater vehicle (or ROV), shows how most krill feed by swimming upside-down directly under the ice, grazing as they go.

Extra cold winters are a boon to most animals living in Antarctica. Colder winters mean more pack ice, and more ice algae to feed more krill, which means more food for all. In warmer years, when the pack ice is reduced, there’s a measurable decline in the krill population, sending shock waves of scarcity through the shallow Antarctic food web.

Even in good years, competition for krill can get fierce. Biologist David Ainley discovered that minke whales drive Adélie penguins from the best krill feeding zones, forcing the penguins to venture farther afield or switch to hunting fish. Humans have also joined the fray, using nets to harvest roughly 100 million tons of krill each year for use in animal feed, dietary supplements, as fish bait, and also for direct human consumption.

Researchers fear that global warming and dwindling pack ice are likely to pose serious challenges for the Antarctic ecosystem. In the short term, however, there is one perk to warmer temperatures: an increased number of icebergs. Marine scientist Maria Vernet has found that these floating oases deliver nutrients to the surrounding water as they melt, creating flourishing (if temporary) mobile ecosystems on and around the bergs.

A North Pole without ice?

“Arctic climate is more sensitive than models suggest,” said J.C. Gascard of the Centre National de la Recherche Scientifique, University Pierre et Marie Curie, Paris, France, in his plenary lecture on “The changing arctic ocean-ocean warming and sea ice extent.” Sea ice is seasonal ice that forms on the surface of the ocean in freezing environments and extends out from the more permanent polar ice-caps and frozen landmasses.

Aerial view of Arctic sea ice.

Gascard reported that in 2005 and 2007, the minimum sea-ice extent (which occurs during the summer season when temperatures are warmer) in the Arctic was far lower than had ever been recorded. Moreover, both were far lower than the Intergovernmenal Panel on Climate Change (IPCC) models had predicted. The IPCC is a scientific intergovernmental body established to provide decision-makers with an objective source of information about climate change.

Arctic sea ice at its 2008 minimum extent, on September 10.

Gascard stressed that the dramatic reduction in the summer extent of Arctic sea ice in 2005 and 2007 were not isolated cases, but part of an evolving trend. Gascard and his colleagues have observed a gradual long-term warming, including a longer melting season, over the last 20 years. During this time, the mean sea ice thickness has decreased by 1.3 meters in most of the Arctic Ocean. Gascard warned that Arctic ice is likely to continuing retreating and that “it will disappear during the Arctic summer in this century.” So why does it matter that sea-ice is retreating? The most sensationalized result is loss of polar bear habitat, but they are certainly not alone in their suffering since many polar organisms depend on the sea ice for their survival. Furthermore, if the sea ice continues to melt, the permafrost on land will also melt, changing the entire Arctic ecosystem with global implications. Stay tuned to learn more about the Arctic permafrost.

Arctic sea ice.

An Antarctic iceberg on the solstice.

Maria Vernet is a marine scientist from Scripps Institution of Oceanography at UC San Diego who studies plankton off the Antarctic Peninsula of West Antarctica. As one of the project leaders for the Palmer Long Term Ecological Research project, Maria has participated in many of the project’s 14 yearly research cruises.

Maria at the helm of a zodiac (small rubber boat.)

The Antarctic Peninsula, experiencing some of the most dramatic warming anywhere on the globe, is also among earth’s most productive marine ecosystems. During winter 2008, Maria studied the ecology of phytoplankton (microscopic plants) and its role within the marine ecosystem at the Palmer Station Long-Term Ecological Research Network (LTER).

The LTER network includes 26 sites mostly in the US, and includes ecosystems from the poles to the tropics. Scientists study the areas from many angles, combining their research to give a broad view of how ecosystems work.