Ice Stories: Dispatches From Polar Scientists » Jean Pennycook Mon, 15 Nov 2010 20:40:36 +0000 en hourly 1 Where Have All the Whales Gone? Wed, 06 Jan 2010 00:36:14 +0000 Jean Pennycook CAPE ROYDS, ROSS ISLAND, ANTARCTICA– Since the early 20th century when exploration of the Ross Sea became common, killer whales have been sighted regularly and described as the most abundant whale in the area. Recently, the killer whales of this area have been divided into three ecotypes based on their feeding behaviors and identified by their eye patch markings. Of the three defined types, A, B, and C, only two, the B and C, are common to the Ross Sea and McMurdo Sound area. Type Cs, now known as “Ross Sea killer whales” (owing to presence mostly in Ross Sea and a bit to the west), feed primarily on fish, mainly Antarctic toothfish and silverfish, while type Bs feed on seals and perhaps Emperor penguins.

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.

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Fish Story Mon, 04 Jan 2010 18:50:06 +0000 Jean Pennycook CAPE ROYDS, ROSS ISLAND, ANTARCTICA– Antarctic Toothfish has become a popular dish, known as Chilean sea bass, in many expensive restaurants around the world. Little is known about this large slow growing fish which does not reach maturity and begin to spawn until it is 16, and can live to be 50 years old. Once surviving the larval and juvenile stages (first few years), growing only a couple of centimeters and gaining only a kg of weight a year thereafter, these fish are a main food source for the top predators in the Southern Ocean, killer whales and Weddell seals. As a society we choose to protect Antarctic wildlife (penguins and such), but this should include the food source of these creatures as well as large predatory, shark-like fish. In recent years the take of Antarctic toothfish has increased which many believe will force Antarctic seals and whales to move elsewhere or die off. Already there appears to be fewer of these fish-eating killer whales in the southern Ross Sea.

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.

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Penguins 1 – Skuas 0 Wed, 23 Dec 2009 18:22:30 +0000 Jean Pennycook CAPE ROYDS, ROSS ISLAND, ANTARCTICA– When Adélie Penguins adapted to live in the harsh environment of Antarctic they pretty much got this place to themselves. Nesting on the ground in other parts of the world is very risky for birds as this makes them extremely vulnerable to the numerous predators. In Antarctica there are not as many predators, but the one that discovered eating is easy in an Adélie penguin colony is the South Polar Skua.

South Polar Skua.

This large aggressive bird is an opportunist. When the seals haul out on the ice and give birth to their pups the Skuas hang around and eat the after birth. At McMurdo Research station they will wait for people to leave the dining hall with a sandwich or cookie in their hand and swoop down for the ‘kill.’ When it’s time for them to breed many build their nests at the edge of penguin colonies where first the penguin eggs then the chicks can be easy pickings among the penguin parents who are just beginning.

Skuas, tag teaming a penguin to get the egg.

Adult Adélie Penguins can defend themselves so are safe from Skua attack. However, while the penguins are nesting, and before the Skuas lay their own eggs, the Skuas work in pairs, one will fly overhead to distract the Adélie and the other will swoop in and snatch the egg or chick as the penguin stretches to peck at the decoy. Often times when I’ve been sitting watching this, I wish that the penguins would someday take revenge.

The Skuas often build their nest close to the Adélie breeding colony so they do not have to go far for their food. But in the following sets of pictures you can see this Skua was very bold, laying the egg within 10 feet of nesting Adélies. At first the Adélies would walk by with only passing interest in the nesting Skua but finally one penguin decided this was too close and challenged the Skua.

A Skua nest very close to a group of Adélie Penguins.

Some penguins would walk by without paying attention to the intruder.

First a challenge.

Then the Skua is evicted from the nest.

Every attempt by the Skua to return to its nest was thwarted by the penguin.

Finally the egg was lost to other Skuas.

Skuas are no match for adult Adélie penguins so the Skua moved off the egg. The penguin did not chase the Skua but stood at the nest and did not allow the Skua to return. Every attempt by the Skua to return to the egg was thwarted, and meanwhile the Skua egg was getting colder by the minute.

Skuas are indeed opportunist eaters. Even exposed Skua eggs are taken. This egg was no exception and once the penguin walked off, with in a few minutes another Skua made this egg its meal. The Skuas abandoned this nest site and will likely build one a much safer distance away next time. Penguins 1 – Skua 0.

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Snow Storms Are Hard on Adélie Penguins Wed, 16 Dec 2009 22:32:42 +0000 Jean Pennycook CAPE ROYDS, ROSS ISLAND, ANTARCTICA– The purpose of an Adélie nest is to keep the egg warm and dry, and prevent it from rolling away. Since it is always near or below 0°C here in coastal Antarctica one adult must be on the eggs at all times or they will freeze very quickly. This year the breeding colony at Cape Royds has experienced several large snow storms. A little snow is okay, but this year the amount is more than usual. The storms, the amount of snow and then the melt run-off all have provided challenges for this year’s breeding pairs. On the other hand, these penguins are Antarctic born and raised; we may feel cold but they don’t!!

Penguins sitting on eggs. In the right-most picture the very busy mate has continued to bring rocks to the nest, to place them on top of the snow.

When storms come the penguin will not leave their nests. To do so would mean their eggs would be blown away or freeze very quickly. During the storm they sit quietly with their face to the wind and wait for it to be over.

Adélie Penguins seem to have a strong sense of where their nest site is even if it is covered with snow! For this group, their sites from last year are under 3 feet of snow. Not discouraged, they simply built their nests on top of the snow pile. How this will affect the egg and chick brooding, hatching and rearing as the snow melts, we are going to find out.

This pair returned to find their long time nest site covered with snow. Instead of building on top of the snow they decided to move elsewhere and found a cozy nest site with a couple of large rocks for protection from the Skuas about 12 meters away. This is nest #3 in our Nest Check and you can follow them throughout the breeding season by seeing the daily pictures here.

Because of their body heat some of the birds are sinking into the snow pile as the days go by. This bird, below, built his nest on top of the pile, but as you can see he is slowly sinking into a larger and larger hole. He is on a nest of a few rocks with two eggs under him. When the female came back it was a challenge to do the nest exchange. We will observe and record the success of this nest.

When the sun comes out and the snow melts, there are small streams everywhere. Small depressions (scrapes) where penguins have built nests in the past fill up with water. This makes it harder to build the nest and the penguins need more rocks. A successful nest will be high enough to keep the egg out of any water run off. The egg will not hatch if it is sitting in freezing water.

The penguins on the left have a challenge to build a dry nest above the water. The third picture shows the result of a poorly built nest in the mud. The egg rolled out and moments later it was picked up by the ever watchful Skuas. The nest shown to the right is a well built nest above the mud, these eggs will be kept dry.

Adélie Penguins are sturdy birds, but stronger and more summer storms pose a challenge to their breeding success. Read how these birds are coping with the effects of climate change here.

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What a Difference a Year Makes Wed, 16 Dec 2009 02:19:27 +0000 Jean Pennycook CAPE ROYDS, ROSS ISLAND, ANTARCTICA– The picture below shows the difference between the ice edge on November 3, 2008 (left) and November 3, 2009 (right) for the Ross Island area. For the penguins at Cape Royds this meant 50 miles less ice to walk over in order to arrive at their breeding colony. As penguins would much rather swim than walk, this was good news. I expected to see penguins arriving earlier than last year and in greater numbers, perhaps building their nests and laying their eggs earlier.

Satellite image of McMurdo sound and the ice cover, Nov 2008, (left) vs. Nov 2009 (right).

At Cape Royds we have a ‘penguin cam’ which is a permanent structure housing a remote camera. The camera takes a picture of the colony every day as long as the solar panels generate the power to keep the batteries charged. Since the research team is not in the field all year round, this allows us to monitor what is happening at the colony when we’re not here. You can see the daily pictures at, as well as a time-lapse of images taken over the last two years. Last year and this year the first penguins were seen the last week of October, so not much changed there, but there were fewer birds and nests being built during the first weeks this season. When we started looking for eggs the picture became even more surprising.

In 2008 the first eggs were seen on November 5th. This year we did not see eggs until November 16th. Plus the number of birds present in the colony continued to stay low. Something was keeping the penguins from arriving, building their nests and laying their eggs on the normal schedule. As the days progressed more birds started showing up and by November 25th the colony looked busy, with many nests completed and females leaving for open ocean to replenish their energy and become fat again.

An early arrival at the colony. He could have all the stones he needed so he built a large nest. Now he waits for the female to show up and guards his rocks from other males as they arrive.

The breeding season in Antarctica is very short. Adélie penguin chicks must gain the weight they need to sustain themselves through their molt to adult plumage before they are able to swim and find their own food. If the sea ice closes in around Ross Island before this happens they will have a huge task walking to open water and food. They can not swim until they have their adult plumage. We do not know what will happen this season, but that is why we are here so we can observe and record this event. We are hoping you will follow along as well.

Did you know that penguin researchers also use the satellites to track penguins when they are out in the open ocean foraging for food? See how they do this here.

Learn more about Adélie penguins at

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The Last Task of the Season Thu, 19 Feb 2009 00:06:33 +0000 Jean Pennycook CAPE ROYDS, ROSS ISLAND, ANTARCTICA– The Adélie Penguin breeding season in Antarctica is short. By late January it is time for everyone to leave including the penguins. Before our team departs our last task is to band the chicks. We select the biggest and most mature chicks in the hopes they will survive their first winter on the ice. It is rare to see one year olds — we will have to wait two or even three years before seeing the chicks we band today. This year the chicks are in good shape: big, strong and heavy.

Catching them means we use a corral to surround the crèche and then move in hopefully herding them into the pen. Stepping inside the pen, we sort out any adults that were caught by mistake, then the smaller chicks we will not band. Now the work begins. Catch a chick, hold it between your legs, place the hard metal band around its wing and press it closed. It is very important to make sure the ends of the band are flush and together otherwise the band may interfere with the swimming ability of the bird.

This pen is used to catch the chicks. We get inside and sort out the adults and small ones, then band the big ones.

Banding the chicks. It’s important to get the band on exactly right, otherwise it will interfere with the birds swimming.

We now say good by to these chicks, leave them alone to finish their molting and find their way to the open ocean and food. Many of the adults have already left, these chicks are on their own.

These chicks have been banded. It may be two or three years before we see them again.

The adults have left these chicks to finish molting on their own.

It’s hard for us to say goodbye. The pile of equipment is the last load of the season. Our amazing helitech solves the puzzle, and still there is room for all five of us. We are covered in penguin guano, feathers and dirt after a day of banding, but feel good as this last task of the research project brings this season to an end.

The last trip of the season. All this equipment must fit into the helo, and the five of us too.

All that equipment made it; now we have to get in. It is goodbye to Cape Royds for the winter.
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The Molt Is On Tue, 17 Feb 2009 19:35:23 +0000 Jean Pennycook CAPE ROYDS, ROSS ISLAND, ANTARCTICA–

Penguin chicks are born with a fine cover of small soft feathers.

In a few days they will loose those feathers and grow wooly thick gray ones. These feathers will keep them warm for the next few weeks, but are not waterproof.

Before the chicks can be on their own, swimming in the ocean and catching food, they must loose these feathers and grow their adult plumage. Adult feathers are strong, dense and waterproof.

During this stage these birds are a source of entertainment for us as they we call them the ‘awkward teenagers,’ each one with its own sense of style.

Adult feathers take a beating during the course of a year in Antarctica. Wind, ice and water take their toll, and each year adult Adélies lose the old feathers and grow new ones. This bird will stay on land or an ice floe as he is unable to swim until the new feathers grow in.
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Rye Rover Rivals Real Rig Mon, 29 Dec 2008 23:21:18 +0000 Jean Pennycook MCMURDO STATION, ANTARCTICA– Eighth grade science students at Rye Middle School in Rye, New Hampshire, got into the act in Antarctica. Under the direction of their teacher Robin Ellwood, they built a submersible robotic camera that was launched in the Ross Sea.

Ms. Ellwood, a veteran science teacher, is also an accomplished ice diver working with a science research group in Antarctica’s Dry Valleys. Headed by Dr. Peter Doran from the University of Illinois, they are studying the fresh water lakes of that remote region. The lakes form primarily from glacier runoff, as it rarely snows and never rains in this part of the continent.

This year the team brought down the Endurance, a large robotic camera and data collector, or ‘Bot’ as it is affectionately called. Gathering data in larger amounts and in a shorter time than humans could do from the surface or diving, this sophisticated machine will map the floor, and provide water analysis of these remarkable lakes. You can learn more about their project and see pictures of the Bot here.

Not to be left out of the project, the Rye students designed and built their own robotic camera which had to be able to function in the extreme cold salty water of the Antarctica ocean. Getting the neutral buoyancy just right and using materials that were appropriate in Antarctica’s fragile environment provided many challenges, but all were well met.

“ScubaDoobaDoo” was successfully launched in the ocean and took its first underwater video in the Ross Sea, Antarctica, November 2008. Its performance was outstanding, it was easy to maneuver and the videos were excellent, reported Ms. Ellwood.

The students can be very proud of their accomplishment. The students’ project was funded in part by the school’s PTA.


ScubaDoobaDoo’s camera in front uses the LED light source next to it. Under the ice in Antarctica it is not only very cold, but very dark. The switch box houses the controls: right and left motors for turning and forward and back motion, the top motor for up and down motion. The video is sent to the DVD player through the 100 foot cable attached to the camera.

ScubaDoobaDoo taking a video of me taking a picture of it.

Close up of one of the motors.

Robin Ellwood getting ready to launch ScubaDoobaDoo in the fish tank, Crary Laboratory, McMurdo.

ScubaDoobaDoo at neutral buoyancy in -1.6 C ocean water. Ready for action.

ScubaDoobaDoo next to the ‘Bot’.

Next to the Bot, ScubaDoobaDoo was overheard saying “When I grow up, I want to be like him.” He is well on his way.

In the video below, see ScubaDoobaDoo perform in one of the large aquarium tanks in McMurdo.

Get the Flash Player to see this player.

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Little Ice Tue, 16 Dec 2008 19:44:45 +0000 Jean Pennycook see my last dispatch). These larger scale visions persists until you begin to look closer...]]> CAPE ROYDS, ROSS ISLAND, ANTARCTICA– When you first come to Antarctica you are overwhelmed by the enormity, vastness and seemingly endless large structures of ice which dominate this continent (see my last dispatch). These larger scale visions persists until you begin to look closer. Ice can be delicate, fragile, intricate and blue. Patterns are created showing that water obeys both the natures laws of chaos and order. Playing a part in the dance, gas bubbles squeezed out of the liquid water during the phase change do not escape from the surface in time and remain prisoners in a frozen matrix until the thawing process releases them Wind too contributes to the creation of patterns reminding us it will not be dismissed as a force in this process.

A single Antarctic snowflake. Two things have always given me headaches: the number of stars in the universe and the number of these in Antarctica.

Prisoners in time, these frozen gas bubbles give pattern and beauty to the ice.

A different pond and a different pattern.

Ice crystals obey their own rules of pattern formation.

A different place in the ice, these formations did their own thing.

These frozen ice waves remind us, the wind will be heeded.

The large ice structures of Antarctica remind us of the power of this place; the small ones, how fragile it is.

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Big Ice Mon, 15 Dec 2008 23:34:19 +0000 Jean Pennycook CAPE ROYDS, ROSS ISLAND, ANTARCTICA– When you first come to Antarctica you are overwhelmed with the amount of ice. Every direction you turn you are surrounded by it dominating and controlling the landscape, white against white. Beautiful and powerful, this visual element controls every byte of memory you will take away with you, and every photo. The first time you stand on sea ice which extends to the horizon in all directions you feel the enormity and significance of this place and finally understand what they mean when they say “Antarctica’s ice influences the global system.” This place has a lot of ice.

Icebergs are broken off pieces of glaciers and contain snow that fell 10 000’s of years ago. When you move close to one, what you see is several 100 feet tall and yet only 10% of its actual size and you come to understand not only how much ice there is here, but also how long it has been here.

Sea ice to the horizon.

The end of a glacier as it comes off the land. Here you see frozen ocean holding the edge of the glacier ice in place. This wall of ice is 200 feet high with 9 times that much under water. That’s a lot of ice!

This is also part of a land glacier which has moved off the land over the ocean. It is called an ice shelf because although it is still attached to the land portion of the glacier it is floating on water. This shelf is the size of France and a couple thousand feet thick. That’s a lot of ice!!!

Icebergs off the coast of Beaufort Island. What you see is several 100 feet high, and only 10% of its size. These are enormous pieces of glacier that broke off from the ice shelf above, floated around for a while and are now grounded. Much of the year the frozen ocean holds them in place.

There is a lot of ice in Antarctica.

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