Layered lakes in the Vestfold Hills

Layered lakes in the Vestfold Hills

Video transcript

In Antarctica, biodiversity is greatest in the ice-free areas where animals and plants can live.

The Vestfold Hills is one of Antarctica’s most biodiverse regions.

An area near Davis research station is being assessed as the site for a new aerodrome.

Dr Catherine King, ecotoxicologist, Australian Antarctic Division
“So this is one of our lake transect sites. You see this lake right here? That’s one of our sampling sites. And what we’re doing in this program is looking at biodiversity across this region.”

Scientists are studying the lakes around the proposed site in unprecedented detail.

Dr Catherine King
”Importantly at Davis we have very complex lake systems and over 300 lakes of varying sizes, from small metres-squared up to several kilometres long. And the lakes in the Davis region are particularly unique because we have a range of freshwater lakes, as you’d expect, but also hypersaline or super salty lakes.”

Comparing the water and the soil between lakes will show if they are connected.

Dr Catherine King
“Our program out here is looking at a range of lakes of different sizes, different salinities. Looking at the biological communities and how diverse they are. And whether there’s any connectivity or differences between those lakes.”

Samples will be analysed in the lab for their DNA to reveal the full range of microscopic life-forms

Dr Catherine King
“That will give us a really good idea of the complexity of the communities, and whether they are similar to pockets of communities that we see elsewhere in the Vestfold Hills.”

[end transcript]

two scientists on rocky shore beside lake
Dr Kathryn Brown (left) and Dr Catherine King collect soil samples in Antarctica. (Photo: AAD)
two scientists sample soiltwo scientists with probe in laketwo scientists put sample in bag with troweltwo scientists in a rocky landscape

Complex lake systems around the proposed site of the Davis aerodrome are being intensively studied by scientists from the Australian Antarctic Division (AAD).

The Vestfold Hills is the location of Davis research station and the proposed aerodrome, and has hundreds of lakes of various sizes and salinities.

Leader of the lakes team, AAD ecotoxicologist Dr Catherine King, said each water body is likely to have different chemical and physical properties, which may be home to distinct biological communities.

“Our program is looking at a range of lakes of different sizes and salinities, and studying the biological communities and how diverse they are,” said Dr King.

Along with water samples, Dr King and Dr Kathryn Brown are collecting soil and sediment samples from the base of each lake or pond, at the water’s edge, and at varying distances from each site.

“We’re looking at what occurs in the soil community as you progress along a moisture gradient out from each lake, or alternatively, from one lake to another.”

“And whether there’s any connectivity or differences between lakes that we might need to be particularly careful about protecting,” Dr King said.

One of the unique characteristics of the Vestfold Hills are meromictic lakes, where the water column is stratified into layers of varying density ranging from freshwater to hypersaline.

“Vestfold Hills has the largest concentration of meromictic lakes on the planet,” Dr King said.

“Between the layers you get very different chemistry, as well as very different biological communities.”

A part of their sampling, the lakes team will tow nets to capture plankton, using inflatable boats to access the larger lakes.

Most of the samples will be analysed by microscopy back in Australia to identify microalgae and micro-invertebrates.

Broader community composition will also be assessed by DNA sequencing of water, algae, and soil samples.

This research will determine whether there are unique communities in the area of the proposed aerodrome area, and how similar they are to communities found elsewhere in the Vestfold Hills.

The Davis aerodrome project is required to undergo environmental assessments under the Antarctic Treaty (Environment Protection) Act 1980 (ATEP Act) and the Environment Protection and Biodiversity Conservation Act 1999(EPBC Act). Public comment is currently open until 26 February 2020 and can be made via the Regulator’s website