December 5th.Kristen Gorman and Jen Blum go out early every day and come back around 10pm. They are among the hardest working people at the station. But what a job !: they spend the day betweenpenguinsYcormorants,petrels andskúas(those birds that look like huge brown seagulls). They count them, mark them, measure them, weigh them. They study exactly what parents and babies eat, when and where. They study the effort it takes for birds to get their food (thekrill), the dynamics of their populations, what happens in the nest. Who dies, how and why. Who eats whom and how does all this fit with global warming, since it is a tightly “packed” chain, and everything, absolutely everything, affects the rest.
“The populations ofadelie penguinsin the area of the Palmer Archipelago, in the Antarctic Peninsula, they are declining, “says Kristen.? Because this is a species that depends on sea ice for many things. For example, they need the icebergs and the extensive ice sheets that cover the sea to rest on them. And they need that ice to catch the krill that lays their eggs underneath? With less ice covering the water, the penguins have to swim farther to get it.
Instead,gentoo penguins(those with orange beaks) need the open waters to catch their own food. They must swim quickly and skip over the water, while building momentum to skim the surface with their beaks open. So these gentoo, who don’t like ice, have been establishing themselves in this area more and more. And the adelia, they have been decreasing.
Where do the adelias go? No one knows for sure yet. They may simply be disappearing from the peninsula. A decade ago there were many. Only on Torgersen Island there were 10,000 couples; now there are about 3,000 left. Have they migrated to other places? It doesn’t seem very viable. The truth is that not all the islands or the coastal areas of the peninsula south of the Palmer Archipelago are an easy environment for adelias. Either they are extremely steep, or they do not have the proper feeding conditions.
And yet Kristen and Jen found a nearly inaccessible colony on theIsla Charcot, a few months ago. This was a great find. Because Charcot has some tough shores. That topography for a penguin is almost like going to the Andes for a human. And yet there they are, in the heights, having to go down to the sea constantly to go back up to take care of the nest. How attractive do they find you? “Nothing less than the appeal of thefood in great abundance“says Jen.? The underwater topography and geology of Charcot are similar to those of the Chilean and Peruvian coasts: it has almost vertical walls that descend to the bottom forming submarine canyons ?, he adds.” This makes the water cold and dense from the bottom, which is loaded with nutrients, can rise to the surface to enrich everything. It is the same that happens in Charcot, and in other similar Antarctic islands, but on a smaller scale than on the South American coast, naturally. “
The discovery could not have been made without the interaction of various instruments and scientific disciplines, since the underwater geology of the islands and the amount of plant plankton in them was discovered by the glider robots. And in turn the robots had to follow the penguins. “The penguins eat the krill, but the krill in turn eat the plant plankton,” says Kristen.
In January, both teams of biologists will explore Charcot again. “It’s hard for me to believe that we were the first to stand on those shores of Charcot,” says Jen. But that’s the way Antarctica is: there is still room for discovery and exploration.
Angela Posada-Swafford
For more informationFollow Angela’s journey in “From Antarctica”
