The study, co-led by Te Whare Wānanga o Waitaha | University of Canterbury (UC) scientist Associate Professor Michelle LaRue, incorporates high resolution (VHR) satellite imagery with field-based validation surveys and long-term data. The VHR satellite imagery uses 30–60-centimeter ground resolution to examine the entirety of the penguins’ range during springtime around the Antarctic coast.
“In a rapidly changing world, we have to constantly push the envelope to combine new approaches with tried-and-true methods if we want to understand the consequences of that change, especially in places we cannot get to,” Dr LaRue says.
The research identified the East Indian Ocean and Weddell Sea areas of Antarctica as being the two sectors of the continent where there is the greatest probability of declines in regional populations of emperor penguins. These locations are where the extent of fast ice generally has decreased in recent decades.
During the study, researchers detected several new colonies, bringing the total to 66 known colony locations. It is now likely that most emperor penguin colony locations have been detected, with around half having been detected with satellite imagery.
Emperor penguin populations have been exceedingly difficult to monitor because of their remote locations, and because individuals form breeding colonies on seasonal sea ice fastened to land (known as fast ice) during the dark, cold Antarctic winter.
Combining satellite images with animal tracking, ground observations and molecular tools, such as genetic analysis, will be needed if researchers want to fully understand mechanisms to describe some of the changes they observe.
Scientists cannot yet explain the population trend. However, additional research should help with a better understanding of the causal factors – including the role of climate change. This new monitoring methodology could also help researchers help in the development of adaptive conservation management efforts.
Funding for this research was provided by the National Science Foundation, NASA; the French Polar Institute Paul-Émile Victor, Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association, World Wide Fund for Nature (UK), and the German Research Foundation.
