Swamp Stomp

Volume 18 Issue 13

Penguins have captured the hearts of many of us, long before March of the Penguins debuted in movie theaters. They are one of the most unique birds on our planet, from their habit of mating for life to their ability to “fly” not in the air, but through the water. For many years, scientists have used penguin populations to study the effects of a changing climate on the home of the penguins, the Antarctic. Recently though, large amounts of valuable new data have been collected and not just from penguin population numbers.  The data demonstrates not only the effects of a changing climate but many other environmental changes, created by humans, that need to be prevented in order to preserve the Antarctic.

At the American Geophysical Union’s 2018 Ocean Sciences Meeting held on February 12, 2018, researchers discussed the growing importance of penguins in the fight to preserve the Antarctic. As the “heart of the Antarctic food web,” researchers have found that penguins’ feathers and eggshells tell the story of the changing Antarctic environment. Penguin tissue cells capture important details concerning the food they take in. These particular tissues contain different amounts of certain chemicals that are specifically found in the fish and other sea life the penguins consume. For instance, krill may be high in the nitrogen-14 isotope and a fish may be high in nitrogen-15. If a penguin consumes a lot of krill, its eggshells and feathers will contain more nitrogen-14 than nitrogen-15.

Over-fishing has been a persistent problem in the Southern Ocean for many years. By observing the food penguins ingest, scientists can discover just how much over-fishing has affected the Antarctic environment, especially in regards to the declining krill population.

Kelton McMahon, an oceanic ecogeochemist at the University of Rhode Island in Kingston,  is using this information to track the changes in the environment. McMahon and his team compare penguins from the wild to captive penguins at the Omaha Henry Doorly Zoo in Nebraska to observe how much wild penguins’ diets have changed. They use different amino acids, as well as the different types of nitrogen isotopes, to study dietary changes. From this information, it has been determined that penguins’ diets consisted primarily of fish approximately 80 years ago, then krill, and now fish once again with the declining krill population. This information is extremely valuable in determining food web changes that may have resulted from over-fishing or climate change. Once scientists have determined what these changes are, they can take the best action needed in order to fix potentially negative effects.

Recently, scientists have found yet another characteristic that makes penguins even more fascinating. From eggshells preserved by vast sheets of ice and collected by researchers, scientists believe that they can determine what the Antarctic food web looked like as long as 10,000 years ago. Just as geologists use radioactive decay of certain isotopes to date the earth, scientists can now use the fossil remains of penguins to see into the past, and give us a new image of a time long ago, another chapter in the history of the home we call Earth.

Sources:

Gramling, Carolyn. “Look to Penguins to Track Antarctic Changes.” Science News. Science News. February 14, 2018. Web. March 20, 2018.