At Sea
The southern ocean gently rocks our sturdy ship, as National Geographic Explorer heads southeast towards the Sub-Antarctic Island of South Georgia. The air and sea temperatures have dropped, and we have picked up an escort of Petrels and Prions zipping across the ocean’s surface catching meals on the cresting swells, while Grey-Headed Albatross are happy for the stiff sea breeze that pushes us along. What amazing birds - staying at sea for years at a time, finding everything they need on the wind and waves, except a stable place to nest.
While we move from one incredible destination to another on this expedition, there is one very obscure place we explore, the underwater world. As Undersea Specialist on National Geographic Explorer it is my pleasure to bring back pictures of the southern ocean using scuba, Splash-Cam, or ROV (Remotely Operated Vehicle). In these costal ecosystems, the underwater niche is just as important as the terrestrial one.
The underwater exploration thus far has been concentrated in southern Argentina, and the Falkland Islands. Both have temperate waters ranging from 45 – 55„aF. Argentina sent a delegation of Southern Sea Lion’s to welcome us into her underwater realm, while the Falkland’s kelp forest revealed, grazing spider crabs, delicate anemones, and the great sun star.
Sailing across the ocean’s surface, one cannot forget how important these temperate and polar seas are for sustaining all the creatures we see in the air and on the land during the voyage. These are some of the most nutrient-rich waters in the world. The cycle of life that is happening below the water’s surface is what will feed the penguins, albatross, and seals through the summer. Longer hours of sunlight are warming the waters, and feeding small phytoplankton (small plant-organisms such as diatoms), through photosynthesis. The phytoplankton then becomes food for the zooplankton (small animal organisms like copepods). Zooplankton are choice meals for birds such as prions, who simply have to dip into the oceans surface and filter these tasty crustaceans out. As we move into the colder waters of the Sub-Antarctic and Antarctic, zooplankton feed the most important animal of all – krill. We say “krill is king,” as it feeds not only the penguins, but seals and whales as well.
For now we bid the warmer waters of the Falklands and South America adieu, but our melancholy feelings are being replaced by apprehension, excitement, and wonderment. South Georgia, for many of us the pinnacle of our expedition and a world unto itself, lies ahead.
