Science from the poles: Penguins and microbes
Photo: Australian Antarctic Division, Kristin Raw
Polar ecosystems of the earth have significant influence on the climate of our planet and are important habitats for organisms uniquely adapted to survive in harsh conditions. Although the regions are vastly different from each other, Arctic and Antarctic systems are among the most impacted by global climate change. However, the remote nature of these areas makes scientific study of organisms and the environment difficult and expensive. Recently, two studies provide further insight into the biology and ecology of organisms in these extreme environments.
1. Adélie penguins in Antarctica
Adélie penguins (Pygoscelis adeliae) live in Antarctica and are listed as “Near Threatened” on the IUCN Red List. Following a winter offshore, the penguins live in colonies on land during the breeding season, reaching populations of thousands of individuals. While hunting, they feed on krill, fish, and squid, often traveling great distances to find food. Populations of Adélie penguins are under threat from a host of factors, including climate change, pollution, and habitat loss. Since they are a keystone species in Antarctica, it is important to monitor their health and survival. Funded by the Italian National Antarctic Research Programme, researchers at the University of Siena and University of Plymouth conducted a study on immune and genetic stability in a colony of penguins in southern Antarctica. With blood tests from 19 penguins, the researchers analyzed presence of erythrocyte nuclear abnormalities and white blood cell levels, finding cell types associated with genomic instability and a decline in immune health, including potential cancer development. As an effect of human activity and climate change, bioavailability of toxic contaminants is increasing and is expected to increasingly negatively impact wildlife. This study provides information on the health of an important species in Antarctica and can be used in the future to monitor changes in the population.
Read the study here:
Silvia Olmastroni, Giulia Pompeo, Awadhesh N. Jha, Emiliano Mori, Maria Luisa Vannuccini, Niccolò Fattorini, Nicoletta Ademollo, Ilaria Corsi. Erythrocytes nuclear abnormalities and leukocyte profile of the immune system of Adélie penguins (Pygoscelis adeliae) breeding at Edmonson Point, Ross Sea, Antarctica. Polar Biology, 2019; 42 (7): 1343 DOI: 10.1007/s00300-019-02522-3
2. Bacteria in salty, cold Artic water
On the opposite pole, researchers at the University of Washington are working to understand microscopic life in one of the most extreme conditions in the Artic. In an effort to understand whether life is possible on other planets, researchers study life that exists in similar conditions here on Earth. One of these similar environments is created in “cryopegs”, or trapped layers of sediment with water at very high salinity levels and below-freezing temperatures. Trapped in permafrost, microbial communities present in these cryopegs could be preserved for thousands of years. To determine whether these microbial communities exist in old layers of permafrost, researchers extract DNA from samples collected by drilling a tunnel through the ice. Within these cryopegs, researchers have found dense bacterial communities and co-evolved viruses, with Marinobacter playing a dominant role. The presence of thriving microbial communities in these extreme conditions demonstrates the vast diversity of life that exists on Earth.