This week at Casey: 21 February 2014

This week at Casey we look at how technology is helping map the area, see how penguin feet are helping study genealogy, and we show off a few photos from recent field trips.

Moss drones

The Casey station surroundings possess one of the largest moss beds in the Eastern Antarctic region. Just around the corner of station limits is an Antarctic Specially Protected Area called ASPA 135, with a significant population of three moss species (Schistidium antarctici, Ceratodon purpureus, and Bryum pseudotriquetrum). Another unprotected but stable moss population is growing at the Robinson Ridge (Robbos), and the largest moss bed is located in Stevenson’s Cove (Clarke peninsula).

For the past few decades Antarctica has experienced changes in temperature, wind speed and stratospheric ozone levels. Decline of mosses, which are very well-adapted to the harsh Antarctic climate, can be seen as an indicator of these climate changes. Mosses are fragile non-vascular plants that are sensitive to any mechanical damage, especially to trampling. To minimise impact of walking through moss beds, scientists from University of Tasmania and University of Wollongong are using light-weight drones — multirotor helicopters (oktokopters) — to investigate the current abundance and health of the Casey moss beds.

In the last four weeks their micro oktokopter flew several times equipped with a standard and a multispectral camera to collect images of moss turfs around Casey. Images stitched into a single mosaic will serve as input for spatial assessment of actual moss bed health. Repeating this survey in future years will allow them to monitor temporal changes of moss bed size and general vigour. Apart of the moss work they also acquired aerial images of the old Casey station, which should help with future soil decontamination at this location. They also performed a short video flight over the abandoned US/AUS Wilkes station in order to document its current appearance. This scientific work is showing that although operating microdrones in Antarctica is quite a challenging task, mainly due to the freezing temperatures and unexpected wind gusts, it is proving to be a very valuable tool for detailed mapping of the station grounds and nearby areas.

Zbyněk Malenovský

Not so happy feet

As the field season draws to a close, I thought it would be a good time to review what we have accomplished this season for the Adélie penguin program. Our main goal was to collect penguin feet from already deceased penguins for genetic analysis in order to quantify genetic diversity of colonies and to assess population structure in East Antarctica. The final tally of feet was a massive 219 from eight colonies in the Casey region. Our team at Mawson were also out collecting feet and will bring back roughly 120 from five colonies.

In addition to investigating Adélie population structure we are also interested in understanding their diet and foraging behavior. This year we collected diet related samples from the Whitney Point colony near Wilkes, including eggshells, claws and faeces. Using a combination of stable isotope and genetic analyses we can determine what the penguins are eating at different times in the breeding season and where their most important foraging areas are. This research will help us to identify any overlap between penguin foraging and any future krill fishing activities.

Our other major focus was past population dynamics and diet. To investigate this we dug holes in abandoned penguin colonies to look for bones and eggshell fragments. These samples will be radiocarbon dated to determine sample age, and then subjected to the same stable isotope and genetic analyses as the modern samples. This will reveal how diet and population structure have changed over the years in relation to changing climate.

I would like to say a massive thank you to all the lovely volunteers who took time out from their own jobs to come into the field with me to cut off penguin feet, dig holes in smelly penguin colonies and haul massive bags of rocks. I wouldn’t have accomplished anywhere near what I did without your help, and it wouldn’t have been half as fun. All my gratitude to Matty, Meg, Clare, Ben K, Nerilie, Tim G, Jane G, James B, Grant, Steve H, Ian, Jukka, Pete R, Laura, Vas and Joe A. I am especially grateful to Dan for being my deadman switch in the lab, Shane for helping with the deeply unpleasant task of disposal of the leftover penguin sediments, Psycho who was with me in the field almost every day and finally Tracey, the organisational queen who made it all possible.

Jane Younger