Diving Deep Below Arctic Ice to Bring Back Our Ocean’s Skeletons

Polar expeditions to explore the ocean are not for the faint of heart. Above the water's surface, you better be on alert for polar bears. Below, you better be game for diving 60 feet under sea ice into freezing temperatures. Watch National Geographic grantee Branwen Williams lead a team to the Canadian Arctic to do both in an effort to better understand how our oceans and the climate are changing over time.

Williams describes leaping from one floating block of ice to another, over freezing Arctic water, as “exhilarating”—the rest of us might call that downright scary. But this fearless passion for the ocean is what drives Williams’ research and exploration; she is determined to help the oceans thrive and survive.

From a very young age Williams loved the ocean, and by graduate school she was studying ways to mitigate the stress and strain humans inflict on it. “I started researching ways that we can create records of how the oceans change because if we want to know how people are changing it, we have to know how it changes by itself,” she says.

Williams’ approach to unlocking the oceans’ secrets is to analyze the hard skeleton bodies of the oceans’ coralline algae. Like the rings of a tree, coralline algae grow in layers, each one representing one year. For a tree, a year with good growing conditions produces a thick ring. For poorer years, the tree’s ring will be thinner. Cut a tree open exposing these rings and you have illustrative evidence of changing atmospheric conditions. Coralline algae works in a similar fashion. Its layers record a veritable treasure trove of data, including shifts in the ocean’s temperature, light availability and carbon composition. But harvesting this algae poses quite a challenge.

Coralline algae is found in the coldest of oceans at the highest of latitudes, from the Gulf of Maine up to the Canadian Arctic, stretching around the globe to the Aleutian Archipelago. Ten months out of the year, the algae living in the Arctic Ocean are snuggly encapsulated under a thick blanket of sea ice.

In 2015, Williams traveled from Los Angeles to the 500-person village of Qikiqtarjuaq in Nunavut, Canada, to collect samples. It took six flights and two full days of travel to get there. “This was the first time that anyone has gone to this part of the arctic to collect our species of algae,” she recalls. Her hope was to find samples that have been growing for a very long time. In some parts of the arctic, 650-year-old algae have been extracted. Williams is striving to find a thousand-year-old algae.

Finding and collecting coralline algae 20 meters beneath the sea ice in freezing water is challenging work and demands unique and specialized skills. “We relied very heavily on our local guide, an Iqaluit hunter.” Williams said, “He guided us to show us where it was safe to stand.” This knowledge grew increasingly imperative throughout the week as the sea ice began to melt. “There was still ice covering the ocean when we got there,” Williams says. “We would use the Ski-Doos to get to and from our field sites. By the end of the week, we were actually using a boat.”

Once at a prospective field site, the crew would use a hand-crank device resembling a giant corkscrew to drill a hole and send a camera down to survey the underwater landscape. When a promising location was identified, the hole was expanded and Eric Brasseur, a French scientist and cold-water diver, went down to collect the algae. Eric was exceptionally qualified for this endeavor, since he was diving in what could be considered as his backyard. Each winter, Eric, his wife, and their two children live aboard a sailboat that they strand over winter in the ice of Qikiqtarjuaq.

This past expedition, Eric retrieved 20 viable samples of algae to send back to Williams’ lab. She later determined that the oldest sample collected was 50 years old. Although this did not surpass the 650 year-old record-setting sample, she considers Eric’s dives, and the trip, an unequivocal success. As Williams’ algae collection grows so does her understanding of the ocean’s complex history and people’s impact within that narrative. “The ocean is absolutely an amazing, massive, dynamic part of our world. Really, my goal is to understand how the oceans change so we can figure out how humans are changing it so then we can know how to try and mitigate some of the negative changes that people are causing. That’s the part I do.”

Branwen Williams is a grantee of the National Geographic Society's Committee for Research and Exploration. Learn more about the science and exploration supported by the nonprofit National Geographic Society at natgeo.org/grants, and see more explorers at work in the rest of the Best Job Ever series.

PRODUCERS/EDITORS: Sharon Pieczenik and Nora Rappaport
SERIES PRODUCER/GRAPHICS: Chris Mattle