9) nzTABS Expedition: Terrestrial Antarctic “megafauna”

Back in the helicopter, and back into the mountains for another soil sampling siege – I’m just about convinced that I am James Bond. Antarctica New Zealand has provided some impressive helicopter logistics, orchestrated by Barry, the operations scheduler at Scott Base to get us to all the 75 sampling sites. It has been most appreciated.

View from the help - Wilson Piedmont Glacier draining inland into Lake Vida

View from the helo – Wilson Piedmont Glacier draining inland into Lake Vida

This time, it was team Blond, not team Bond. And Kristi and I were specifically on an Invertebrate hunt, as we hiked back to base camp over two days.

Kristi, myself and Alia in the base camp tent.

Kristi, myself and Alia in the base camp tent.

Kristi Bennet is a Masters student from the University of Waikato studying population genetics of springtails in the McMurdo Dry Valleys. Springtails are the largest living terrestrial organism in Antarctica, measuring in at a whooping 1-3mm. The only other visible living invertebrates are Mites. These are the ‘lions and tigers’ of Antarctica, top of the food chain – the megafauna! Springtails are found worldwide and are the words most abundant soil arthropod. They have a long evolutionary history and are one of the first arthropods that show up in the fossil record. There are 3 species found in the Dry Valleys, Antarcticinella monoculata, Neocryptopygus nivicolus and Gompheocephalous hodgsoni. During this expedition Antarcticinella monoculata was found, for the first time since the 1960s. The current hypothesis for their distribution is that they are remnants from Gondwanaland and have survived the once warmer continent becoming a polar ice cap.

Kristi Bennet - Masters student researching Antarctic springtails

Kristi Bennet – Masters student researching Antarctic springtails

Hunting for Springtails and Mites is a fine art. They have very particular places they like to hang out. They are found on the mountain peaks, in areas with some water, where snow naturally accumulates. They like to live under flat black rocks, sheltered from the harsh winds by larger boulders, on north facing slopes, with good school zoning and close to the shops…. For us, it means spending lots of time on our hands and knees turning over rocks. So I am a glaciologist by trade, and until this point the field groups had had very little luck in finding any mites or springtails. It was when I finally turned over a rock to see tiny red mites scuttling across the underside of the rock, that I truly understood the microbiologists passion and yelled at Kristi “oh oh oh, Ive found some mites!!!”. 

Next we had to collect the mites. A specially designed aspirator was used. They are sucked up through a tube, and to prevent eating them, they are caught on a filter and fall into a plastic vile. Mites and springtails are also found in the soil samples. To separate them form the soil, in the lab the soil is mixed with a sugar solution and any organic matter, including the mites and springtails floats out. They are then scooped out, preserved in ethanol and taken back to New Zealand for genetic analysis.

Alia and Kristi working with samples in the field lab at base camp

Alia and Kristi working with samples in the field lab at base camp

By the end of the field time, the total count of springtails found was approximately 100, and 300 mites were also collected. Needless to say, Kristi was pretty happy with the count, and will be spending time in the lab, studying the genetics of these springtails.

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