By Dona Bertarelli
I want to thank all our partner schools, in France and Switzerland, and the 2,000 students who are following us. Whenever I can, I will be answering your many questions throughout this journey around the planet, a journey that we are taking together to discover the wonders of our world.
With all the crew of Spindrift 2, through our observations and our encounters, not only with marine life, but also with the islands and peninsulas that we pass, with the meteorological phenomena we experience, and with the birds and the stars that accompany us during our voyage, we will help you to live this adventure, like Phileas Fogg in Jules Verne’s famous book. We are calling our Spindrift for Schools series - Out of the Classroom.
The Seabirds of Antarctica
As we have rounded Cape Horn and started sailing back up the Atlantic following the coast of Argentina, we have gently left the South Seas. As a farewell, many birds have followed us during these past days, more than we ever seen in our entire rounding of Antarctica. As sudden as it might sound, and surprising as well, the sea temperature increased from 3 degrees to 15 over night and the seabirds of Antarctica gave way to the flying fishes.
Many species of seabirds spend the majority of their lives at sea, far from the eyes of humans. As a result, little is known about their habitats and movements. Despite their mystery, seabirds still provide one of the most visible indicators of ocean health, acting as sentinels of what is going on beneath the ocean surface. It is particularly telling, but not altogether surprising, that over the past several decades, during which time many of the world’s fisheries have suffered precipitous declines, the populations of many seabird species have also suffered dramatic reductions in their numbers, declines that are linked to commercial fisheries targeting their feeding areas, making them amongst the most threatened group of birds in the world. Some 45 species of seabirds live south of the Antarctic Convergence, but only 19 of these breed on the Antarctic continent itself. These include pelagic, or free-ranging, species such as albatrosses and petrels. By contrast, coastal species, including skuas, cormorants, terns and sheathbills, forage close to the shore. And last, but certainly not least, are 7 different species of penguins, flightless birds who make up in aquatic dexterity, what they lack in the air.
The seabirds of Antarctica face unique challenges. Able to withstand the harshest climate on earth, each species has its own unique survival techniques and characteristics ranging from shared parenting and monogamy to flexible webbed feet and feathering that gives them greater buoyancy and insulation. Long-lived and slow to reproduce, the common thread among these remarkable denizens of the southern oceans is the important role they play in Antarctica’s intricate food web, both as predator and prey. Seabirds need forage species—in particular, tiny Antarctic krill—to survive. They can feed on huge amounts of these tiny crustaceans and expend enormous amounts of energy in doing so. For example, the emperor penguin is the deepest diving bird in the world, capable of reaching depths of more than 600 meters in search of food. But some unlucky few may end up as meals for orca whales or leopard seals, top predators in the Southern Ocean who rely on seabirds and other prey for their own survival.
Other birds, like petrels, thrive on the continent. Antarctic petrels live along the entire Antarctic coastline, nearby islands, and even on the pack ice, where they have little competition for food. They are able to stay so far south because they meticulously clean, dry, and oil their feathers to insulate them from the harsh weather. The snow petrel is the most southern breeding of all birds, and they have been found living up to 435 miles inland on the continent of Antarctica. Like Antarctic petrels, feather care is critical to these birds. Taking “snow baths” helps keep them clean, and their thick, beautiful white feathers help to keep them warm from wind and ice.
Terns are a familiar sight in coastal waters around the globe. But the most impressive is the Arctic tern which arrives in large numbers in Antarctica each summer to feed, following a journey of some 19,000 kilometers from their nesting grounds in the Arctic, only to turn around and do the same journey in reverse, the longest migration of any species of bird on Earth.
As I mentioned in another post, the albatross could truly be considered the “ruler of the high seas.” Built to fly, the wandering albatross has the largest wingspan of any living bird—measuring 2.5 to 3.5 meters—a wingspan so long, that they can stay in the air for many hours, riding the wind currents without ever flapping their wings.
Albatros in La Maire strait | © Yann Riou - Spindrift racing
There are many other species of birds that rely on Antarctica and the Southern Ocean for survival, and all of them have special adaptations that help them thrive in the cold, snow, and ice. But as climate change begins to warm the ocean they depend on, altering their food supply and forcing them to adapt in short periods of time to conditions which increase their vulnerability to weather, predators and lack of food, they will face greater challenges.
Climate change, for example, is predicted to have hugely detrimental impacts on emperor penguins, with projected losses in some colonies of over 80%. The only way to address the problem of warming temperatures in Antarctica, as is the case everywhere in the world, is to bring down emissions of carbon dioxide associated with the burning of fossil fuel. However, there are a number of steps that can be taken to make it easier for these birds to survive in a changing world. In particular, the establishment of large, full-scale marine reserves combined with management measures designed to prevent the localized depletion of krill and forage fish that are their primary food source will help these spectacular birds to better withstand the changes that are coming, and hopefully ensure their presence in the waters of Antarctica for years to come.