The Southern Ocean and South Georgia Island
Geography and Climate
The continent Antarctica is located in the south of our planet. It is surrounded by the Southern Ocean. In the Southern Ocean the (ACC) flows clockwise around Antarctica. This cold ocean current is separated from warm sub-antarctic water by the Antarctic Convergence where the cold water – -1°C (30 °F)in winter to 4°C (39°F) in summer of the Southern Ocean sinks down from sea level to 800 m below sea level. The difference in water temperature from the antarctic to the sub-antarctic water causes a ring of fog around the Southern Ocean.
There is also a different flora and fauna. Especially Antarctic krill can only be found south of the Antarctic Convergence in the Southern Ocean. This krill is a important source of food for whales, seals, penguins and fish.
The Island South Georgia is located south of the Antarctic Convergence. It is part of the British Overseas Territory South Georgia and the South Sandwich Islands. South Georgia is a 35 km (22 mi) wide and 165 km (103 mi) long island, which is located at approximately latitude 54 south and from longitude 36 west to 38 west. It is a mountainous island which tallest mountain Mount Paget is 2935 m tall.
Most parts of South Georgia Island are covered by ice and snow, but at the coastline there are regions free from ice and snow in summer. The average temperatures in South Georgia change from -5°C- 1°C in June to 2°C-9°C in February at the – warmer – northern side of South Georgia. Föhn winds can cause much higher temperatures, up to 29°C.
The weather on South Georgia Island is often very windy. On the leeward side of a mountain this wind can cause turbulences. Above this turbulences there can be stacks of standing waves with lentil shaped clouds, which are called lenticular clouds.
A second characteristic weather phenomenon for South Georgia Island are katabatic winds. Above the mountains covered with ice and snow cold air accumulates. This cold air suddenly flows down like an avalanche causing strong winds in which it is often difficult to stand.
This elephant seal weaner was lying at beach with almost no wind at all.
5 seconds later there was katabatic wind in which I was hardly able to stand. Since the beach was filled sand this causes a katabatic sand storm.
Seabirds
Heading to South Georgia Island with a ship you will be followed by different types of sea birds. You can often watch black-browed albatrosses. They can easily be identified by the black feathers at the albatross’ eyes. Like all albatrosses Black.browed albatrosses are tubenoses. At the end of this tubes are salt glands though which the tubenoses secrete a saline solution. With it’s wingspan of 2.1 m to 2.5 m and a weight of 3-5 kg it is able to use the strong winds near the surface of the ocean for long distance flight without much effort. Black-browed albatrosses hunt fish, jellyfish, squid and crustaceans.
Black-browed albatrosses start breeding in colonies approximately at a age of ten. A couple of Black-browed Albatrosses can raise one chick every year. The breeding season is from September to March. The chicks leave the nest from late April to May. The black-browed albatross can live 30 years or more.
Like it’s relatives they are endangered through long-line fisheries. Long-line fisheries uses lines, which can be longer than 100 km and are are equipped with hooks and bait. Eating this bait albatrosses are catched by the hooks. They are dragged under water which result in drowning.
With a wingspan of 250 cm-350 cm the wandering albatross has the largest wingspan of any living bird and can live up to 60 years. They are mainly white, have a pink bill. Most parts of the top and some of the bottom of the wings are black. They feed squid and fish. Starting with age 11 Wandering Albatrosses mate for live and lay a single egg in December. The egg is incubated alternating by male and female and hatches in March. The chick leave the nest in November or December.
There are type different species of giant petrels, which can be distinguished by theirs bill tip. The Northern Giant Petrel has a red bill tip and the southern giant petrel has a green bill tip. With 180-210 cm giant petrels have a slightly smaller wingspan than Black-browed albatrosses. Their food consists mainly of carrion and young or sick animals. A single egg is laid from August to November and the chick fledges between March and May.
Cape petrels are another kind of Tubenoses, which follow ships in smaller or larger flocks. With 80 cm wingspan and 500 g weight they are much smaller than albatrosses and giant petrels. They have a black head, a black bill and feet, a white belly and black and white checkered upperparts. They feed on krill and other small crustaceans, nut also fish and squid.They breed single, in groups and colonies up to 2000 pairs. They lay a single egg in November and the chick fledges in March.
Snow petrels are also tubenoses and have a white plumage providing a good camouflage for snow. Bill, eyes and feet are black. With 75 cm wingspan and up to 450 g weight they are slightly smaller than cape petrels. They live and breed mainly on the Antarctic mainland, but can also been seen in South Georgia Island. They can frequently be seen near glaciers and floating ice. They lay a single egg in November or December. The chick fledges in February, April or May.
Penguins
King penguins are nearly 1 m tall, have a black head and a white belly. They have a silver grey back and an orange-golden plumage near the ears and at the neck.
The beaches of South Georgia Island are a good place to raise a chick for king penguins. After incubating their single egg on their feet for 8 weeks a small brown chick hatches from it’s egg. Five weeks later the brown chicks join a kindergarten for another 45 weeks. Since this breeding cycle is longer than one year, king penguins at best can raise two chicks in 3 years. Their food mainly consists of fish and squid.
With up to 90 cm gentoo penguins are a somewhat bit smaller than King Pinguins, have a black back and head and a white front. They also have a white patch above their eyes and a white ring around their eyes. Their feet are whitish-pink. Their bill is orange-red and have a black plumage at it’s top and bottom. Like all other penguins they mostly move and hunt in small groups. Their food consists of krill and other crustaceans, fish and squid. They typically raise two chicks in summer.
Chinstrap Penguins have a white front, a black Back and a characteristic black chinstrap. They are approximately 53 cm tall. Their food consists mainly of krill, but they also eat fish and other crustaceans. Chinstraps lay two eggs in a small depression. The chicks hatch 30-40 days later, stay in nest for another 20 days and join a kindergarten for 50-60 days.
Macaroni penguins are 70 cm tall, have a white front and a black back and head and red eyes. On the front of their head they have characteristic golden-yellow plume of feathers. Macaroni penguins feed krill, fish and squid. They lay two eggs in November, but normally raise only one chick which fledges in February or March.
Rockhopper penguins breed on sub-antarctic islands like the Falklands. They are significant smaller than macaroni penguins, but have also red eyes. They have yellow feathers above each eye but no yellow patch on the forehead. Their feet are pale pink with black soles. Their food consists of krill, other crustaceans and fish. They can raise up to 2 chicks each year.
Magellanic penguins live in South America and the Falklands. With 55-70 cm height they are taller than rockhopper penguins. Apart from their pink skin near their eyes they are only black and white. They have a white breast with a black band and another black band across their throat. On each side of their head they have an c-shaped white band. Their back and their feet are black. They feed mainly on fish, but also on squid and crustaceans. They breed in holes and under bushes and in hollows. They lay two eggs and raise up to two chicks.
Seals
The beaches of South Georgia are dominated by two different species of seals: Antarctic fur seals and southern elephant seals.
The Antarctic Fur Seal is an Eared Seal . They were nearly extincted by hunters at the beginning of the 20th century, but now in the breeding season the beaches are populated with so many fur seals that some one can not cross. Male Fur Seals are up to 2 m long and weigh up to 200 kg. From November to January they set up small territories (60 m² to 20 m²) at the beach in order to mate with female Antarctic Fur Seals, which are up to 1,5 m long and weighs up to 50 kg. The best territories are located near the ocean. Males defend their territories aggressively against other males and also other intruders like humans since they do not want to loose their territory. Antarctic Fur Seal bites are said to cause very dangerous infections.
Southern Sea Elephant Seals are earless seals, also called true seals. Elephant Seal Bulls are the largest of all Seals, weighing up to 4500 kg with a length up to more than 5 m. Only Sea Elephant Bulls have the long nose. Sea Elephant Cows are obviously smaller with a weight up to 900 kg and a length up to 3 m. In the breeding season Sea Elephant Seal Bulls live at the beach as beachmasters with harems of up to more than 30 Seal Elephant cows. The beachmasters do not eat but lie at the beach defending their harem if needed. The cows went ashore in September and October and give birth to their black pups. Drinking milk within 23 days they gain weight from 40 kg at birth up to 120-180 kg. Then the cows become fertile again, mate with the beachmaster and abandon their pups. The pups will become silver-gray weaners for 4-6 weeks eating nothing. This weaners live in groups at the beach and seem to be very curious – presumably they are searching their mothers. One has move constantly to not get surrounded. The weaners molt, learn to swim and feed.
