A Monthlong Journey to Antarctica
Aug. 2—Punta Arenas, Chile
I’m at the southern tip of South America, in the city known as the gateway to Antarctica. Sunlight beams through clouds onto the gray waters of the Strait of Magellan. At the end of a huge concrete dock is my home for the next month: the Nathaniel B. Palmer, a 308-foot National Science Foundation research vessel, its bright orange hull rising from the water in warm contrast to the wintry surroundings.
The Palmer’s glow reminds me why early European explorers named this place Tierra del Fuego, the “Land of Fire.” As Magellan and his crew sailed into the strait that now bears his name, they saw canoes piloted by indigenous people who had painted their skin and built bonfires in their boats to keep warm while at sea.
Five hundred years later, the Palmer—with a crew from the National Oceanic and Atmospheric Administration’s Antarctic Marine Living Resources (AMLR) program—will embark on a monthlong voyage south through the Strait of Magellan, across the Drake Passage, and onward to the Scotia Sea, the Antarctic Peninsula, and the South Shetland Islands. This is the fifth and final year that this AMLR group will make the winter trip.
It’s an adventure traveler’s dream itinerary. But I’m here to work alongside scientists from the United States, Chile, Germany, and Peru, in hopes of better understanding the variability of Antarctic krill, the shrimplike crustacean that forms the base of the food web in the Southern Ocean and is a staple food source for many Antarctic species, including penguins.
It’s the middle of the austral winter, so aside from a smattering of other scientists working in research stations across the Antarctic continent, the Palmer will be alone in the vast darkness as it crunches its way through the sea ice. Most research in Antarctic waters takes place in the summer months, when migratory species and Antarctic predators are most active. Very little of this work has been done in winter, leaving much about this fragile ecosystem during these dark and cold months unknown.
Krill and the species that feed on them face growing threats. The Antarctic Peninsula and the surrounding waters are warming faster than anywhere else on Earth, which scientists suggest is driving declines of the tiny creatures that have adapted to thrive in sea ice conditions.
Also, over the past 40 years, commercial fishing for krill—used in nutraceuticals such as omega-3 supplements and in feed for farmed fish, including salmon—has become increasingly concentrated in this area, particularly in coastal regions. This is reducing the local availability of krill near penguin colonies, which can make it harder for penguins to find food.
What we learn on this voyage could add to the body of science that informs fisheries management policies, which might help the krill populations and the predators that rely on them. We will also gather a host of data on other aspects of this near-pristine ecosystem. But first, onward to the ice. I’m well- aware that I’m headed for some of the roughest waters in the world—and even the most experienced polar scientists are impressed to hear that I’m doing this in the winter. While I’m pretending to be a hard-core Antarctic explorer, I’ve brought along some seasickness medications just in case.
We are now in the Bransfield Strait; icebergs hundreds of feet tall tower in the distance. I’m in the ship’s lab when I hear loud rumbles along the hull and feel the boat vibrating. I run to a porthole and see waves of pancake ice—large slabs with edges rounded from rubbing against each other—undulating on the waves around us.
My first view of sea ice is thrilling, but it belies a grim reality: Because of warming trends in the region, vast portions of the Scotia Sea and the Bransfield Strait are uncharacteristically ice-free this winter. While this is bad news for Adélie penguins and crabeater seals, the thin ice will allow the Palmer to forge farther south than the AMLR Winter Survey has ever gone. Our destination is the southern part of the Gerlache Strait, an area of austere beauty, where we hope to find Antarctic krill. And where there are krill, there are penguins, seals, and whales.
In the few days we’ve been on the ship, my body clock has been turned upside down—apt, perhaps, considering that we’re at the bottom of the Earth. I work from 8 p.m. to 8 a.m., so I rarely see the full midwinter sun, which appears for only about seven hours a day, with about two hours of twilight on either end. I have no complaints, though, as the dusky daylight hours bathe this alien landscape in a gauzy, muted color palette. The wildlife doesn’t seem to mind the low light conditions either; I’ve spotted seabirds—albatrosses, skuas, and a few species of petrel—and a couple of fur seals.
I’ve also seen a bounty of other wildlife through a microscope lens. We are here in part to study zooplankton—tiny animals that drift in the ocean—and learn how they are responding to changes in their environment.
We’ve entered the Gerlache Strait, renowned for its spiky icebergs and humpback whales, which help draw summer tourists on cruise ships. Within hours, I too fall for the Gerlache, which is at once spectacular, raw, humbling, and alive. The crystalline water is sprinkled with pieces of sea ice and icebergs that growl and creak. Every shifting wave, rotating iceberg, and evolving cloud feeds an ever-changing kaleidoscope of color and shape.
In an area hardest hit by the impacts of climate change, the Gerlache and its surrounding waters are also sensitive to human impacts. In addition to an annual decline in sea ice coverage, the region is one of the most heavily fished for Antarctic krill. With an overall decline in krill biomass, the cumulative impacts on the area are fueling fears that overconcentrated fishing is pushing the penguins that live here to travel farther to find food, putting them at risk.
Despite these challenges, almost on cue I hear faint splashing sounds below, signaling a group of Adélie penguins jumping through the water. Adélies are small, topping out around 28 inches, but as they leapfrog past one another they look even tinier, dwarfed by the icebergs, our boat, and the massive scale of our surroundings. If someone hadn’t pointed out the penguins, I would have missed them. And they were right in front of me.
While each day on board the Nathaniel B. Palmer holds surprises, the survey conducted by the Antarctic Marine Living Resources program is a finely tuned operation: The ship has followed a predetermined grid each year since 1990, allowing the scientists to sample from the same sites every mission to help show year-over-year changes in the ecosystem. Since 2012, researchers have carried out this work in winter, further broadening our understanding of this remote and unique ecosystem.
Researchers use acoustic equipment to locate krill and measure their biomass. AMLR staff then use the data to prepare biomass estimates for the entire region. In daylight, crew members stationed in what we call the ice tower, high above the deck, peer through binoculars to observe conditions, including the prevalence of sea ice, as well as whales, seals, penguins, and other seabirds.
Once we reach a predetermined sampling site, we deploy a monitoring instrument 750 meters deep, which measures ocean conductivity (salinity), temperature, and fluorescence (the presence of chlorophyll). These indicators help scientists assess how well a given site will support organisms at the base of the food web—and by extension, the species that rely on them for food.
We’ve already encountered temperatures as low as minus 20 degrees Celsius (minus 4 F) with a wind chill of minus 47 C (minus 53 Fahrenheit), winds over 40 knots, swells splashing onto the deck, and thick patches of sea ice that can cause hourslong delays. So before going on deck to deploy the Isaacs-Kidd midwater trawl—a conical net-and-bucket device used to collect zooplankton samples—we don our extreme cold weather gear, steel-toe rain boots, and hard hats.
The winch operator lowers the net from a crane to a depth of 170 meters, while the captain holds the ship at a steady 2 knots to maintain tension on the cable and minimize damage to specimens caught in the net. Once the net reaches the desired depth, the winch operator slowly brings it back to the surface, where the deck crew hoses it off and removes the codend—a little bucket attached at the end of the net, where, if all went well, the zooplankton samples have been collected. I will then spend hours in the ship’s lab staring at the microscopic creatures, which hold clues to the health of an ecosystem and are often bellwethers of how life is adapting to change.
The Antarctic Marine Living Resources Winter Survey sailed to appointed monitoring sites to gather data on a critical staple for penguins, the small fish called krill, which have been heavily fished for commercial purposes in recent years. (© The Pew Charitable Trusts)
Sept. 2—Punta Arenas, Chile
After a long, choppy crossing over the Drake Passage, which put me in sickbed for a few days, we’ve finally made it back to South America. As the Nathaniel B. Palmer eases into dock, I’ve never been so happy to see dry, level land, but I’m also not ready for the adventure and discovery to end. I’ve finally experienced the beauty and serenity of the Antarctic, and I will miss it, just as I’ll miss working with the dedicated team of world-class scientists who have accomplished so much here in recent years.
Prior to the first U.S. AMLR Winter Survey five years ago, scientists could only speculate about how the Antarctic ecosystem fluctuated in winter. Now those researchers know that a large percentage of Antarctic krill overwinter in the Bransfield Strait, making it a key refuge for species like Adélie penguins and crabeater seals—a fact that raises further alarm over the rapid decline in sea ice coverage.
Still, the scientific community has only begun to understand Antarctica and the Southern Ocean in winter. To continue expanding that knowledge—and to help others safeguard the region’s unique biodiversity—will require a continued government commitment to maintain missions to the region, including during its coldest, darkest months.