Summer Series 2017 - Spectacular scenes under the 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. 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,” Dr Lohrer said.
New Harbour sea ice can go for years without breaking out, and this multiyear ice can grow up to 4.5 meters thick. When the ice is thick, very little light can penetrate the ice to fuel primary production (for example algae) 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.
Water samples were collected from the benthic incubation chambers twice and day, after which they were processed in the “laboratory”. Drew Lohrer and Jen Hillman make measurements, record data, and filter samples. About 300 filtered seawater samples were frozen and brought back to NIWA Hamilton’s analytical chemistry laboratory for analysis. [Photo: Patrick Degerman.]
A large Polar Haven tent, used for eating and meal preparation. A team of nine camping for 20 days requires a lot of food. Red food boxes with dry goods, chilly bins of frozen meats and veg, and LPG bottles for the stoves are lined up outside the tent in an orderly fashion. This was one of three heated huts at camp. The team slept in unheated tents atop the sea ice. [Photo: Patrick Degerman]