Antarctica: Life beneath the ice

A pencil urchin covered in epibionts including a large sea squirt (left) and several varieties of sponge. The image was captured at about 15m depth at New Harbour. Photo / Peter Marriott

Niwa has released new photos revealing an abundance of life in the freezing waters beneath Antarctica's ice.

In October, a team of scientists from New Zealand and Finland travelled to Antarctica for a scientific diving expedition under the ice.

Led by Niwa marine ecologist Dr Drew Lohrer, the aim of the expedition was to explore how climate change is affecting the marine biodiversity in Antarctica.

Image 1 of 10: A pencil urchin covered in epibionts including a large sea squirt (left) and several varieties of sponge. The image was captured at about 15m depth at New Harbour. Photo / Peter Marriott

A unique combination of species and isolation has provided an area largely unaffected by human activity.

The divers found that there have been surprisingly big changes in the coastal seafloor communities in just a few years.

"What used to be a very stable, sparse and food-deprived animal community on the seafloor under the thick ice in New Harbour is now much richer with more species and higher densities of animals," Lohrer said.

New Harbour sea ice can go for years without breaking out, and this multiyear ice can grow up to 4.5m thick.

When the ice is thick, very little light can penetrate the ice to fuel primary production, and therefore food supply to the animals on the seafloor is limited.

The rich community now observed is most likely a rapid response to the sea ice breaking out two years in a row, resulting in more light and higher productivity in the ecosystem.

While under the ice divers captured spectacular images of the creatures they saw which they will use for further study.