03 November, 2015 by Nicholas O'Flaherty
Researchers from the Auckland University of Technology (AUT) flew drones with special cameras over the Taylor Dry Valley in Antarctica to study microbial life.
The data from those flights in 2014 has now been analysed and reveals some remarkable characteristics about the peculiar forms of life thriving there. The drones were specifically tasked to take multispectral images of the unique cyanobacterial mats in the region.
Professor Steve Pointing, director of the Institute for Applied Ecology New Zealand at AUT is one of the world’s top scientists studying the Dry Valleys and oversaw the research.
“There are actually two different types of mat. There is a greenish-orangish one which is a cyanobacterium that grows extremely fast but is restricted to just around the lake edges. The other one is a thick dark black mat which can grow in slightly less waterlogged areas,” Pointing said.
The drone flights were used to map the extent of biology specifically around the lake margins. They provided scientists with images that allowed them to determine if the cyanobacteria was hydrated and doing photosynthesis or if they were dried out and dormant.
The scientists discovered that the two distinctly different types of mats actually reproduce in different ways. The greenish mats are able to survive this dry desert environment because they have the ability to dry out and essentially hibernate. Once dried, these mats are broken up by strong katabatic winds of up to 322km/h which strews bits and pieces of the mats everywhere. When these pieces encounter moisture, they begin to grow again.
The black mats grow into huge leathery carpets which may continually expand for hundreds of metres.
The Discovery of Life
With temperatures as low as -68 degrees Celsius, it was assumed there was no life in the Dry Valleys.
“The Dry Valleys is the coldest-driest desert on the planet. The general consensus for decades was that there was pretty much nothing living there,” Pointing said.
But what geologists first thought were copper deposits turned out to be cyanobacteria. Pointing decided to map out where these tiny lifeforms were and was surprised at the results.
“It was simply incredible. What we discovered is they’re pretty much everywhere. I call it this microbial blanket. Literally every exposed rock surface, if its sandstone or granite, has this green layer beneath the surface of essentially microbial plants.”
In this formidable environment these cyanobacterial mats are harnessing carbon dioxide to build their bodies. They are taking in nitrogen and releasing oxygen in what’s referred to as primary productivity - the first input of carbon to the biological system. It’s assumed the nematodes found here must be feeding on the mats.
Scientists were so amazed that life could survive in such a hostile environment that they decided to look at its genetic make-up. They used a GeoChip to analyse the many thousands of genes related to stress and metabolism.
“We found out the microbes that live in the rocks have got a much bigger set of weaponry to fight stress than the ones that live in the soil because they are exposed,” Pointing said.
Dry Valleys Conservation Plan
The Dry Valleys is the largest ice-free region of Antarctica and is designated as an Antarctic Specially Managed Area (ASMA) which restricts human activity there. But Pointing says that the Antarctic is already showing signs of human intervention with campsites and trails clearly evident. He and other scientists are keen to make sure that this geologically-beautiful environment can be conserved and a solid responsible management plan developed.
“The research in the Dry Valleys has moved from being one of discovery-based science to very much an applied angle to try and work out the metrics we’ll need moving forward to manage it as a resource, as and when people start going there for tourism,” Pointing said.
Tourism is a greater threat to this landscape than climate change. If the temperatures rise here, we may just see the introduction of slightly higher-level plant life such as moss. But when a human steps anywhere on the surface, they leave a footprint which will scar the land for decades.
“The whole point with the drones is that we’re trying to develop a method where you don’t need to put people on the ground. The whole push is for zero-harm in Antarctica,” Pointing said.
For the 2015/2016 season, Pointing will lead a drone and rover team to create a 3-D topographical map charting areas which have been affected by human activity. He wants to create an “index of disturbance” in the hopes of preserving this incredible landscape for the future.
“The Dry Valleys are quite special because they are hauntingly strange compared to human environments. There is nowhere else like them.”