Expedition explores life that spent thousands of years under ice


Fearsome ice kept a Ghent biologist from exploring newly uncovered waters in Antarctica, but an alternative plan turned up a similarly rich diversity of species

Thriving in the dark

Last month, Ghent University (UGent) marine biologist Ann Vanreusel left for the South Pole on an ambitious mission: to explore life that had been hidden beneath an ice shelf for up to 120,000 years. While the plan ultimately had to change because of local conditions, she certainly didn’t return empty handed.

In July last year, an iceberg about four times of the size of London calved off from the Larsen C ice shelf on the eastern side of the Antarctic Peninsula. While this was a negative environmental effect linked to climate change, it also created opportunities for scientists, who could analyse the newly exposed seabed covering an area of about 5,820 square kilometres.

“It was a unique chance to get a look at the ecosystem that had existed under the ice for thousands of years,” explains Vanreusel (pictured), “with species that didn’t need light to survive but perhaps lived on chemical energy such as methane gasses. We had to be quick because sunlight causes the development of algae in the water, which transforms the marine ecosystem.”

Vanreusel was meant to collect samples in order to investigate smaller invertebrates, like minuscule crustaceans and worms, living in the sediments. “These species may be invisible to the eye, but they are often pioneers, among the first to colonise new habitats.”

The UGent professor was part of an international team led by the British Antarctic Survey. Unfortunately, the research ship, RRS James Clark Ross, couldn’t make it through the thick sea ice quickly enough. “In the end, we could only travel eight kilometres in one day, with still 400 kilometres to go,” says Vanreusel.

Plan B

So the team switched to plan B, an exploration of the Prince Gustav Channel, also on the Peninsula. It was covered with ice until about 20 years ago.

“This channel has so-called deep basins, which allowed us to take samples much deeper than normal – more than a kilometre below the surface” says Vanreusel. “One hypothesis is that these basins formed a refuge for species during times of heavy glaciation.”

The team will now analyse the assembled samples but could already determine that the basins contained a rich diversity of species. Vanreusel also hopes she can join a new effort next year to explore the area at the Larsen C ice shelf, set up by a German institute this time.

Newly uncovered waters deserve the status of protected areas, teeming with life that is scientifically valuable

- Biologist Ann Vanreusel

Such research missions also serve a broader goal of providing arguments as to the unique character of these newly uncovered areas in Antarctica. “We have to avoid that they are immediately used for fishing,” Vanreusel explains. “They deserve the status of protected areas, teeming with life that is scientifically valuable.”

The luck of another Antarctic expedition this winter, the Belgian Belgica120, was even worse. This team’s goal was to examine biodiversity in the Gerlache Strait along the Antarctic Peninsula 120 years after the Flemish explorer Adrien de Gerlache did so – the first and only time it had been done.

On the second day of navigation, 26 February, the engine of their boat malfunctioned. The team hopes to have another go next year.