In Antarctica with the Tara Oceans Expedition (December 30, 2010 to January 28, 2011)
What will be Tara’s itinerary on the way to Antarctica?
Tara will leave from Ushuaia (Argentina). The distance, crossing Drake Passage to the first islands of the Antarctic peninsula, is 500 nautical miles and should take 3 or 4 days. Afterwards the boat will sail another 200 miles to reach the Sea of Weddell.
Tara will do this voyage between South America and Antarctica during the full austral summer, beginning December 30. Weather conditions are variable at this time of year, with depressions that are less severe than in the middle of winter. But the swell is always present.
Where in the Antarctic peninsula will scientific sampling be done?
Tara scientists will start doing soundings in the Drake Passage as soon as weather conditions permit, on the way there, as well as on the return trip. This passage is studied all year long thanks to oceanographic vessels, as well as anchors and buoys equipped with captors that measure the physical parameters of the water in this region.
It’s very important for Tara to measure these same parameters, but especially to take samples of the organisms present in function of the physical characteristics of the water. This is a very interesting zone, where the Pacific and the Atlantic mix. Living organisms that move through this passage wind up in the Malouine Current, already studied by Tara Oceans between Buenos Aires and Ushuaia in early December.
As for the Antarctic Peninsula, we will do sampling stations between the volcanic island of Deception and King George Island, then continue south to the entrance of the Weddell Sea.
Do sampling techniques need to be changed because of the weather conditions?
Temperatures may approach 0°C so our scientific instruments will be heated, especially the Rosette, before and after being put into the water. The wet lab will also be heated during sampling stations. And of course the crew will wear clothing adapted to this climate.
We have on board special tubing used during Tara’s Arctic Drift expedition (2006-2008). We’ll use this tubing to circulate the heat produced by our power unit, and thus warm both the wet lab and the Rosette.
What will be the exterior and interior temperatures?
Outside, it will be between -5°C and +10°C, the temperature of the seawater oscillating between -2°C and +2°C. Seawater moderates the air temperature. Inside Tara it will be 15 to 19°C thanks to central heating.
Will it be night or day?
Most of the time will be daylight. Nights will be short, in semi-darkness lasting between 2 and 4 hours, depending on Tara’s latitude.
How are navigating conditions in Antarctica?
The route to the Peninsula passes by Cape Horn, known for severe storms. Tara will probably experience very heavy seas, with huge swells and cross winds as she sails down to Deception Island. The Furious Fifties are usually faithful to their reputation, with winds of more than 50 knots, some snow, and very rough seas.
Tara is at ease in these conditions, sailing at about 9 – 12 knots, with 2 reefs and staysail. Life on board remains “comfortable”.
Towards Antarctica, Tara will encounter “brash”— masses of ice fragments, “growlers”— large pieces of ice floating on the surface, and even some icebergs, including gigantic tabular icebergs in the Weddell Sea. Tara will certainly rub up against the ice-floe, without getting caught in its embrace.
What is the scientific interest of Tara taking samples in Antarctica?
The diversity of the samples, from viruses to macroplankton, using the same techniques as in other oceans. The possibility of comparing all the world’s oceans via the same techniques is certainly the most important aspect of this expedition. In the Antarctic zone studied by Tara, plankton is abundant. Biodiversity is less, but there’s a greater quantity of plankton than in other oceans. It’s imperative to study the austral ocean where consequences of climate change are strongly felt, causing important changes in the plankton community.
Who are the crew members and scientists on board?
Head of the team is Hervé Bourmaud, Tara’s captain for 5 years, who participated in the Arctic Drift of 2006-2008. He is assisted by experienced sailors: Baptiste Régnier, Mike Lunn, Alain Giese and François Noël.
Among the scientists on board, the chief is Marc Picheral who has navigated in the Arctic and on every other ocean. He will be assisted by 2 engineers who have already sailed on Tara, and are both familiar with this region: Céline Dimier and Hervé LeGoff. Hervé also participated in Tara’s Arctic Drift.
When does the Weddell Sea become free of ice?
This is very variable, changing every year. The early austral spring seemed promising, with a large, ice-free band along the Peninsula; but for the past 2 weeks the tendancy has reversed, and ice is forming again. Let’s hope that the wind system end-December will push back the ice towards the south.
The team will go on land. Where and why?
The mission takes place essentially at sea. The team will go on land to visit scientific research bases (Chilean, Chinese, Russian) on King George Island. They will also ‘stretch their legs’ for a few hours on Deception Island or on other islands at the entrance to the Weddell Sea.
Of course we will respect all the rules that apply in this region (as per the Treaty of Antarctica) concerning the fauna and flora, minimizing the impact of our expedition on the local environment.
Has this type of expedition to study plankton already occurred in Antarctica?
Plankton has been studied since the beginning of research in the austral oceans. Recent research can be summed up in these essential points:
-- Influence of environmental changes on planktonic communities (global warming, ozone hole, ocean acidification, etc.)
-- Study of yearly variations in concentration of Antarctic krill (tiny cold water shrimp: Euphausia superba) especially focusing on its role for the larger predators (birds, seals, whales), its exploitation and variations relative to gelatinous organisms (salpes). We have noticed that in warmer years salpes dominate, and in colder years, krill dominates.
-- Study of plankton associated with sea ice (‘young’ ice, 10 to 15 cm).
-- Bio-geography of plankton on a large scale via the program Southern Ocean Continuous Plankton Recorder organized by Graham Hosie of the Australian Antarctic Division and involving several other countries.
-- Physiological and biochemical adaptations of plankton to extreme conditions
-- Ecology of fish larvae
-- The austral ocean is very rich in silicium, element used for manufacturing glass. Many species of diatoms have an exoskeleton (carapace) made of glass. Diatoms are the type of phytoplankton predominant in Antarctica. When they die, they sink to the sea floor because their glass carapace makes them very heavy. They carry with them the carbon and silicium stocked throughout their life.
As a result, the austral ocean is one of the most efficient carbon sinks on the planet.
What’s more, populations of diatoms are the very foundation of an important food chain: they are the principal food for krill.
Tara Oceans Press release