The observation tube allows us to sit underneath the ice and observe the penguins when the enter the water. There are other creatures that we can see. Here are a few photos.
First of all, the ob tube collects platelet ice rather quickly. The sea water is at approximately –2 C, which is below the freezing point of water. Any object in this water provides a crystallization site and the water freezes out around it.
This is the observation tube, as seen by one of the camera logger birds. You can just make out the collection of ice crystals on the lower half of the ob tube. Paul and Jessica cleared the ice from the windows the last time they went diving.
There are several species of jellyfish in the water. Paul was able to photograph one as it drifted past. This species isn’t very large, only a few inches across.
Of course, we see Weddell seal frequently. Here’s one that decided to explore the ob tube and swam quite close to it.
The real stars of the water are the penguins, naturally. Here are three of our birds. Notice how dark the ice has become compared with the photos taken earlier (above). Algae is starting to grow on the under side of the sea ice and that growth is blocking the light.