Wednesday, February 27, 2019

Antarctica: a Continent at a Crossroads --- Guest Photo Essay ---

Travel to Antarctica takes about four days from leaving your house to first sight of land. As a photographer traveling there for the first time, my interest was in the colors of the ice, the stark monochromatic landscape, and the sheer vastness of the continent. I was looking forward to this backdrop to photograph penguins, seals, and whales, but I had only cursory knowledge about these animals. What I found was a bustling and interconnected ecosystem full of life. 

The first part of the journey by ship is crossing the Drake Passage. The stretch of ocean between South America and Antarctica is notorious for rough seas, but we were in luck with smooth sailing. Various species of albatross cruised past the bow while giant petrels crisscrossed in the wake of the ship. After about 36 hours at sea we spotted our first iceberg and the shadows of the South Shetland Islands.


When visiting Antarctica, there is a requirement to check and decontaminate all gear prior to setting foot on land. While completing this process our ship pulled alongside an enormous iceberg. Dubbed A57a based on its point of origin, it is a tabular iceberg, or piece of ice shelf, about 12nm long by 5nm wide. The iceberg calved off of the Filchner-Ronne Ice Shelf in 2008 and it has traveled almost 1,000 miles to its current location. While not nearly the largest iceberg of its kind, A57a dwarfed the ship and the humpback whales feeding alongside it.

One thing you learn when you travel to Antarctica is that there are many different kinds of ice. NOAA defines an iceberg as ice greater than 16 feet above sea level, with a thickness of 98-164 feet. While tabular icebergs like A57a qualify in size there are also gorgeous blue glacial icebergs. Smaller chunks of floating ice are called bergy bits and growlers. There is also pack ice, which forms when floating ice is driven together by wind and waves, brash ice when the sea is covered in small fragments, fast ice when the ice is connected to land, and sea ice when the sea itself has frozen into a flat expanse.


After spending some time at iceberg A57a, we made a stop at False Bay, a quiet cove sheltered from the wind. During a small boat tour, we spotted 20 leopard seals lounging on pack ice. This was a surprising number to find in such close proximity. Leopard seals are typically solitary hunters whose diet includes fish, penguins, and smaller seal species. They are huge animals that can weigh around 1,000 pounds and they are nearly an apex predator with only the occasional killer whale to worry about. Leopard also seals make a variety of strange, otherworldly noises. If you have never heard them, they are definitely worth a listen. Scientists have monitored these vocalizations during breeding season and have found that visual counts may underestimate leopard seal populations.  


Next up was a visit to Paulet Island, home to about 100,000 breeding pairs of Adelie penguins. The island is rocky, ice free and very crowded with simple pebble-reinforced scrapes that the penguins use as a nest. Adult penguins and chicks occupied every flat surface and pungent guano stained most of the land a dull red. At this time of year Adelie penguin chicks are nearly full grown and going through the process of molting their down. Most chicks looked like miniature punk rockers with downy mullets; their plump bodies covered in grime from life in the colony. The chicks were eager for food and constantly pestered their parents. 

While penguin chicks are developing, one parent will stay with the chick to keep it warm until it becomes thermally independent. Then both parents will leave the chick to search for food. Penguins feed their chicks be regurgitating a slurry of partially digested fish and krill into their mouths. Adult birds have enzymes and antibacterial agents in their digestive tracts that allow them to store this food for a few weeks without it going bad. Having built in preservatives allows one parent to protect and feed the chick while the other parent forages.


Brown Skuas, large seabirds with stout bills, circled the penguin colony looking for weak chicks to prey on or carcasses to scavenge. While some people compare them to vultures they are better described as an opportunistic predator. During penguin breeding season, skuas will steal eggs and take chicks whenever they can. In fact, researchers believe that skua breeding season is timed to take maximum advantage of the sudden uptick in available food. Skuas will also eat fish and scavenge food from other sources such as seal carcasses.


Another bird found around penguin colonies is the Snowy Sheathbill. You may hear about animals having an ecological niche and this bird is no exception. They will eat nearly anything - from seal placenta to fecal matter to algae growing on rocks. While they play a vital role as the Antarctic clean-up crew Snowy Sheathbills will also steal penguin eggs and gang up on adult penguins to get them to disgorge food. They are plump, white, homely pigeon-like birds belonging to the only bird family that breeds solely on Antarctica. They are also the only bird on the continent that does not have webbed feet and they avoid water. During winter, Snowy Sheathbills migrate north to South America.


Sailing in the Antarctic summer, the waters along the northern Antarctic Peninsula were mostly ice-free. The ship rounded the northern tip of the peninsula and headed for the Weddell Sea. During this part of the journey, we made a stop at Brown Bluff and were able to observe a colony of Gentoo penguins raising chicks. We all laughed as we watched a parent run away with a noisy chick trailing behind. Later we learned that penguin parents purposely lead the chicks away from the rest of the colony to feed them without harassment. Here we also got our first glimpse of penguin highways - deep furrows in the snow that make travel easier between the colony and the sea. Penguins establish them early in the breeding season and use them all summer long.


Later that evening we spotted a pod of killer whales nearby. The whale researchers on board told us that these were small Type B killer whales, or “Little B’s. Interestingly, killer whale research in the Antarctic has suggested that each of the four types of killer whale seem to occupy distinct ecological niches with each feeding on different types of prey. Most people are familiar with Type A killer whales. Their favorite food is Weddell seal and they will locate seals by spy hopping - peeking above the surface of the water to see what is there. The whales then coordinate to form a wave and wash unlucky seals off the pack ice and into the sea. By contrast, scientists believe Little B’s feed exclusively on fish. 


As the whale research team set off to attempt to ID individual killer whales and gather DNA the ship was surrounded by an astonishing number of baleen whales - fin whales, humpback whales, and even a critically endangered Antarctic blue whale! There were whales in every direction. The humpback whales coordinated feeding by using bubbles to concentrate schools of small crustaceans called krill and then surfacing, mouth agape, through the tightly packed school. The whales were so close we were able to see their baleen plates – built-in filters in their mouths used to strain the krill from the water.


Many animals in Antarctica, including birds, seals, fish, and whales, feed on krill. While krill are only about the size of a paperclip, they are a keystone species of the Antarctic food chain. During certain times of year, they can form in large enough masses that they are visible from space. One issue to keep an eye on is the commercial fishing of krill for products like omega-3 supplements and as food for both fish stocks and people. It is difficult to quantify the impact of commercial hauls as krill populations can vary with changes in the environment, but a collapse in krill populations would be dire for the Antarctic ecosystem.

We spent the next few days exploring - kayaking, hiking, even taking a plunge into frigid Antarctic waters - all while continuing to learn about Antarctica from the various scientists on board the ship. Different scientists presented each day and were happy to teach and answer questions. I learned a quite a bit and gained a much better understanding of the Antarctic ecosystem than I could have imagined. Given their knowledge, I asked many of them what they thought about Antarctic tourism and every one had a similar answer - if people come then they will care and if they care then people will want to preserve it. 


One of the last stops our ship made was at a Gentoo penguin colony at Jougla Point on the shore of Wiencke Island. The island forms part of a natural harbor that was used by whalers at the turn of the 20th century. The shore is littered with whale bones including a nearly intact humpback whale skeleton. Like many places on Earth, people rushed to exploit Antarctica’s resources during the 19th and 20th centuries. They hunted penguins, seals, and whales – in some cases decimating entire populations - and sold the extracted resources for profit. Fortunately, prohibitions on hunting and protection for these species have allowed many populations to recover.

For our last stop, we took a short trip to nearby Port Lockroy on Goudier Island. The old British outpost had seen the whalers come and go, the fear of an Axis takeover during WWII come and go, and is now a historical site complete with a small museum, post office, and gift shop. The site is a popular stop funded by tourist dollars and various vessels anchored nearby. We could see hikers climbing the glacier across the channel under sunny skies in relatively warm weather. Antarctica is, by international treaty, a land preserved for peaceful purposes and scientific discovery. It is also a tourist destination on a planet confronting the potentially existential challenge of global warming. It is at a crossroads where the conflict is between having people see it and want to preserve it and the high cost of getting there.





About the Author

Jen Cross has a Masters of Science in Enginee
ring and works in new product development. She has leveraged her background in science to learn and understand more about wildlife biology, ecology, and conservation

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